- Apologies dear Reader- I have reworked this blog entry to remove much of the repetition and bitterness over incorrect materials and wasted time!
The battery in the Excel is a type 067 but type 027 has the same dimensions and offers improved performance. I bought an Exide version for about £50 which should let me use the original battery strap and cover with its newly installed replacement turnbuckles.
I also have a problem with the battery cables- largely of my own making! I had got quite fed up with constantly attaching and re-attaching the battery terminals, so I removed these (the neg was soldered and had to be cut off) and fitted a pair of Halfords quick-release terminals. This was an error! Those terminals do indeed grip and release the battery posts in a convenient fashion; but the grip to fasten the battery cable is very poor. In general there are three acceptable ways of fastening a battery terminal: Solder, Crimp or use a screw on terminal where two screws penetrate the conductor wire. Soldering is best but I worry about doing this in position. I don't fancy naked flames anywhere in the boot or near the tank. Crimping is to my mind safer on the car, and seems to be of two types- a socket that is crimped around the wire using a hexagonal crimp, or two wings which are folded and crimped in on top of one another using an Anderson crimper. Crimped terminals are sometimes soldered as well giving a good solid joint with excellent conductivity. Sadly the Halfords terminal uses none of these methods. Its a simple screw clamp rather like the cable grip found in a domestic plug: The screws are puny and don't penetrate the copper conductor. If the cable is under any strain at all it just slips out of the clamp!
Quick release battery terminal- Wire clamped in grip plate by a screw at each side- its pulled out again
Top view 
"cable grip" style very puny clamps
The negative cable provides the only connection between battery and car; everything electrical earths eventually through this contact so its vital to keep it in good order at both battery and chassis terminals.
At the battery end, my cable is now just a few inches too short to reach the terminal without strain and keeps pulling out. I can either replace it or extend it, and as extending it is cheaper I will try that first. Lotus used copper cored battery cable. The copper interior is 8 mm diameter and the cable including insulation is 10mm diameter. I realise that this gives a predicted copper area close to 50mm2 but I ordered some of that and it was far too big... the wire seems to be 35mm2..? This I later discovered is a common confusion. Even some suppliers will send the wrong size cable. As a working assumption I now assume all multistrand cable is actually the size below its measured and calculated size because of the gaps between the strands, although the disparity does reduce as the cable size decreases. So a bundle sized at 70mm2 is probably 50; one sized at 50 is probably 35 and one sized at 35 is probably 25! I ordered new cable, solder-or-crimp-on terminals for both positive and negative battery connections and a butt joining sleeve to connect a short extension to the cable. I also ordered new terminal covers as my existing were split.
Battery Post Terminal
I bought a Chinese made hydraulic crimper from Ebay- seems to be similar to the harbour freight model although 8 ton rather than 10. This was very cheap at £15 and should be fine for the occasional use I envisage. I also bought some 35-50mm terminals both battery bolt on type and eyelet fixings.
8 tonne hydraulic crimper
Butt joining tubes
From the foregoing it should be clear that it was my intention to do this job "properly". In the event, it didn't turn out that way. Firstly I trimmed the wire to fit the new terminal-cutting back the insulation over the length of the socket.
Insulation stripped from wire to depth of socket
I could then slip on the terminal cover and the heat shrink needed to finalise the terminal...
...and then I tried to crimp it! There are several videos online and the crimper I bought is similar to that sold by Harbor freight (USA) and others- although mine is only an 8 tonne version. Most videos are from the US and state all wire sizes in AWG- for both wire and terminals. Great if you buy your materials in AWG, but in the UK they are sold by cross-sectional area.
My initial experiences weren't good. This was largely due to mismatches between cable, fitting and die size. Although a 35 cable does fit easily into a 35-50 post terminal I found that it was virtually impossible to crimp tightly enough to hold the cable and when I did so the terminal promptly fractured. I will investigate the right way to crimp these terminals but in the meantime I was able to reconnect a new bolt-on type terminal. I also fitted the new battery and and although the cable is stretched, it could reach the new battery (Exide Premium EA612 Carbon Boost 61Ah 12v Type 075). Thus for the first time I was able to fit the battery carrier, cables and cover to finally neaten up the boot.
Installing new battery and restored clamp- new turnbuckle female halves (these are cheaper if you buy Range Rover turn fasteners)
... connecting...wire a bit tight still.
Well it looks nice and the starter motor turns with more ooomph now!! The cable is still too short and once I get more terminals and solve the crimping problem (or solder the post terminal on!) I will extend it to make a more comfortable fit. I will update this blog at that point but since I'm also waiting on getting the car up on ramps to get at the chassis connection and exhausts (see below) I thought I'd post now and update later!
Case installed
Crimping Revisited!
For what its worth my experience:
What follows has been gleaned from my extensive experience of at least a week, two lengths of cable purchased and about half a dozen terminals destroyed! It may help you, but bear in mind it may be/probably is wrong! If anyone can supply a more accurate guide then I will be delighted- send me a comment or PM me and I will be happy to put it here.
I had several attempts but this is what worked for me... If you don't want to read my painful voyage then here is the conclusion!
- Use SEIWA tin plated brass terminals
- Use 7mm ID terminals (25mm2) and connectors for both 35 and 25mm2 cable.
- You may need to neaten a 35mm2 strand bundle with a 16 or 10 die before it will slip in.
- Crimp battery post terminals with a 25mm die
- Crimp 35mm2 cables in butt and eyelet terminals with a 25mm die
- Crimp 25mm2 cables in butt and eyelet connectors with a 16mm die.
For anyone more interested in what I actually did then the account follows...
Post terminals- I bought tin plated brass SEIWA terminals in 2 sizes specified by internal diameter 7mm and 11mm from nnc-tuning (eBay). I did try other types but they cracked- possibly due to my error. These worked and I'm sticking with them in future. The 11mm was really too big for use on this car.
Two post terminal sizes, sold by ID; 11mm on left, 7mm on right
Smaller terminal ID 7mm 
and OD 11MM
I tried to ID the cable size I was working with- this is the cable I was sent as 35mm2. The inner bundle diameter is 6mm and the cable outer diameter (inc insulation) is about 8mm. This gives a calculated area of the core as 28mm2 and I suspect its really 25mm2 cable. In any event it would slip firmly into the smaller 7mm ID terminal with minimal compressing
Internal diameter of copper bundle 6mm.
External diameter inc insulation 8mm.
The cable I had bought would fit comfortably into the 7mm terminal, but how to crimp? The recommendation is to use the same size die as the cable area, but perhaps its better to consider the terminal you are about to use. This was a 7mm post terminal intended for 25mm2 cable. Test-aligning a 35 mm2 die showed that it wasn't likely to compress the fitting much and the 25 gave a better looking gap and so should compress well.
Cable inserted into 7mm terminal
35mm die surrounds terminal- little compression is obtained when the die is closed
I therefore inserted the cable into the post terminal...
25mm die still has room to compress
And crimped well using the 25mm die pair
I slipped on the heat shrink and cable terminal cover, shrinking the tube
I then crimped a 25 sized butt join connector onto the other end. This is a thin walled terminal and the 25mm2 dies seemed too small for this application. I therefore used a 16
This is where I got yet more evidence that the 35mm2 cable supplied was actually 25 since the cable in the car was larger- it was too large to fit into the terminal unless pre-crimped. I squeezed it with a 10mm die to neaten the ends.
25mm cable butt connector crimped onto the other end using a 16mm die.
...and it then fitted nicely. I used a 25mm die to take the larger cable into account. The join was then...
... covered in heat shrink...
Butt joint- 16mm crimp to new cable (upper) and 25mm to existing (lower)
..to make a neat butt join.
I could then refit the battery case- its a better fit now that the cable has enough length to bend naturally onto the terminal without lifting the carpet or displacing the battery cover.
Overall its now my view that crimping is difficult to get right and confusion in cable sizing is largely to blame. This is probably why there are a lot of soldered and bolted terminals out there. I am not happy that I have ended up with a smaller diameter cable connecting to the battery and I will probably change that later. For the moment I'm going to stick with it as a week spent buying wrong cables and connectors is too unpleasant to repeat just yet. It seems to me that the US system of marking and matching terminals to cables using AWG could remove much confusion. It would also help if UK cables were similarly embossed with their CSA.
Chassis Connection.
The chassis connection is made at the rear underneath the car. The cable penetrates the body, exiting the boot at the front and there are a number of grommets and sheaths to prevent it chafing. It terminates in an eyelet bolted on to the chassis. This seems an obvious place to corrode and I'd like to check and clean the contact under the car. This attachment is apparently accessible via the rear right-hand wheel arch. I don't know what mine is like because I haven't found it yet! I will need to raise the car to get at this connection so I'll leave the underside work until I can drive the car up onto ramps and tackle the exhaust at the same time.
... on a different tack...
I will just note two unrelated observations that emerged from my considerable time spent in the boot. These will need tackling in due course.
Firstly, the wiring loom crosses the boot and passes through the carpet at the top right above the battery. It then crosses above the battery to connect with the rear light. However there seems no way to fasten it securely to the top of the boot as it passes over the battery and the self adhesive clips used previously have long failed. I'm having to hold it out of the way in the picture above. This means it looks anything but neat! I'm not sure what would be best to hold it up out of the way and out of sight but I will see what I can find. Sadly as this is the outer skin of the car I can't use a screw fastening.
Secondly, I found that there is a very brittle tube that seems to run around the boot and dives under the carpet on the the RHS. In my case this is not (or no longer) connected to anything and its somewhat mysterious. I did identify this and describe it here.
Wiring loom passing above battery. Old failed adhesive clips present
Brittle plastic tube underneath carpet on RHS- apparently dipping down to leave boot at rear right corner.
Thursday 26 January 2017
Battery, terminals, case and cables
Tuesday 24 January 2017
Carburettors continued light at the end of the tunnel?
Greetings to my faithful reader! I hope you haven't lost interest during my latest lull in activity. I am still awaiting my new floats. Motorsporttools-uk (trading through Ebay) may be cheaper, but they are no-where near as prompt in dispatch as Eurocarb. They took 4 days to mail the floats and another 2 to arrive! Great if you don't mind waiting- but its hard to wait if you are stuck like this....
Its been bloomin' cold here, and although I have forced myself out to the car, it wasn't pleasant. To be frank, the weather may even have been the source of some of my problems! Well anyway, if you recall I was getting a series of non-sensical observations suggesting that my fuel was both too high and too low at the same time! I'm now pretty sure that a good part of this was down to my battery: this was clearly on the way out and making it supply juice in below zero temperatures was obviously not a good idea. I had taken the slowing of the pump ticks to mean that the fuel had reached pressure... whereas in reality it probably owed more to battery failure and fuel bowls may not have been filling properly. Recharging improved matters no end and both carbs immediately pee'd copious fuel out of the trumpets as soon as I energised the ignition- clearly what had previously appeared as too low a fuel level setting was actually very high! However, resetting the floats on the front carb to 15mm then gave me far too low a level again. It seemed I could get levels of 25mm (overflow) or 32mm but nothing really in between. Now the battery has been eliminated as a cause of this variation I had to look elsewhere.
The web guides suggest that in order to check fuel levels (floats out) you should connect the fuel line, energise the system and wait 30 sec for the float bowls to fill. I can say categorically that this doesn't work- certainly not if you are disconnecting the fuel hoses as I have now started to do, because each re-connection introduces air locks into the hoses and these do affect the carb fuel levels even though they probably should not. Its necessary to loosen the fuel pipe-to-carb unions to bleed the air out and bring fuel to the carbs before they will fill properly. Luckily for me the outer casing of my fuel hoses has already fallen off (!) eventually I will recover with "Roundit". However at the moment I can at least monitor fuel flow and airlocks easily. Its probably also a good idea to crank (or preferably run) the motor for a little while if you can before resting it (motor stopped, fuel pump on) for 10-20 seconds to let the levels settle. This will ensure that you get consistent values at each test. However the fact remained that I was still getting fuel levels about 30 mm at a 15mm float setting instead of the expected 27mm.
It was at this point that I happened to notice the droop down distance of the floats seemed to have become rather large. I had become rather obsessed with achieving an exact 15 mm float setting and hadn't appreciated that as I changed this by a variety of tab and arm bending steps I was also altering the float droop. This is controlled by the stop tab at the rear of the float arm yoke. Droop had crept up to around 35mm and in a man of my age excessive droop is never something to be welcomed! To be fair I hadn't really thought that this setting could have any bearing on fuel level and so had paid it little attention. Its tricky to adjust this tab but I managed to bend it inwards and set the droop height back to 25mm as per Mr Hammill's advice. Check floats again, reassemble, retest... Hey presto fuel level now 27.3 mm with floats set at 14.9mm!!! Joy and rapture!! I have no idea how or why the droop distance affects fuel level but my experience here was that it does. So, front carb now behaving!! ****
***Sadly this didnt stand the test of time and in subsequent measurements it reverted to 30.9mm again. I have no idea why, I have even changed the floats and still get the same fuel level. Currently I'm thinking that this must result from performing the determination on a slope. What ever the true fuel level, I am now confident that all floats are set correctly and this level of fuel is sufficient for running.
I have added a summary of how I would do this floats out test in future to my original post on float level adjustment. Its chronologically out of place but might assist anyone who is just looking for a method and doesn't want to go through all of my struggles.
... Joy sadly short lived as I now set about resetting the rear carb. It too had an excessive droop distance and so I set the floats back to as close to 15mm as I could make them and the droop to 25mm. I re-pressurised the fuel, but the fuel level was still low at 30mm despite my best efforts. However on the credit side, with both carbs set up as specified, the motor did start and actually ran rather well after it had settled down. I was able to run it up to temp for the first time and observed a charging voltage, good oil pressure and eventually a water temp reading on the gauge. The thermostat opened and I got water circulation through the heater- thankfully without leakage from my newly repaired hoses although I was unable to confirm whether the otter switch works or not. Furthermore of course, I have no idea how the motor would behave under load but it wasn't all bad news. I'm pleased it was running so well.
My next step was to set the timing with the strobe. Set statically I had achieved 8 deg btdc when tested by strobe. Using the strobe I reset this to 10 deg btdc at idle speed. I had hoped that this would improve running and possibly the fuel drippage problem but sadly this was not the case. If anything the motor runs rougher now than when set at 8 deg btdc. So matters are improved, but I would be deceiving you if I said that the fuel-in-the-trumpet problem was now solved, its not! Although the front carb (apparently with the correct fuel level) looks pretty much cured, there is still fuel visible in both barrels of the rear carburettor suggesting that this carb at least is running very rich. I think the timing change has shown up these defects in carburation so I need to re-address this problem. Given my progress to date, I may be going around this loop for a while!
Tim Engel does mention that although the enrichment devices fail so rarely that there is no description of them in any book or on any site I can find, they can fail occasionally and when they do they can allow excess fuel through. This failure he states is usually down to the "washer"... sadly there is no washer listed on the Dellorto parts diagram in this area, but I believe this is because its usually supplied as part of the choke piston (fitted into the bottom a little like the washer in the piston of a plumbing ballcock valve) so it might be necessary to renew the whole piston.
In order to test the cause of this difference between carbs I swapped carburettor lids/float assemblies. The front carb still ran well but the rear still flooded. I therefore conclude that the flooding problem is not related to float setting or enrichment device, but must be determined by the lower part of the carb.
Currently I am wondering if the anti reversion spacers are fitted correctly (cone towards engine). These spacers reduce backflow of gases from the manifold and such a backflow might push fuel through the overflows and acceleration pump. My blog shows that I had fitted them correctly but can I be sure?
The second thought that occurs to me is to suspect the acceleration pumps themselves. Mr Hammill advised leaving them well alone- so I have (!) but this does assume that they have been set up correctly in the past and I have no guarantee of this. Since the motor has had a very chequered history the pumps may well been "tweaked" to offset some other problem in the past. Since the motor has now been rebuilt and the carbs cleaned and rebuilt, then any such tweaks would now be out of date.
In order to check these points I had to remove the carbs again. Immediately this showed that there was no problem with the spacers, these were indeed correctly installed with the cones pointing in towards the motor.
When I took the spacers off it was clear that cylinders 3 and 4 (rear) had been running rich with a deposit of soot around the manifold edges. This is to be exected given the excess fuel in these two barrels but it again indicated that I needed to sort out the carburettors, and given that fuel levels are definitely not too high (if anything maybe a little low), the two items that could be responsible for over richness: To my mind the front running candidates are the enrichment device and acceleration pump.
I had difficulty in getting my head around the operation of both of these and I have therefore written my own "take" on their operation, servicing and adjustment which I will move to a second post. This at last enabled me to sort out the excess fuel in the trumpets.
Its been bloomin' cold here, and although I have forced myself out to the car, it wasn't pleasant. To be frank, the weather may even have been the source of some of my problems! Well anyway, if you recall I was getting a series of non-sensical observations suggesting that my fuel was both too high and too low at the same time! I'm now pretty sure that a good part of this was down to my battery: this was clearly on the way out and making it supply juice in below zero temperatures was obviously not a good idea. I had taken the slowing of the pump ticks to mean that the fuel had reached pressure... whereas in reality it probably owed more to battery failure and fuel bowls may not have been filling properly. Recharging improved matters no end and both carbs immediately pee'd copious fuel out of the trumpets as soon as I energised the ignition- clearly what had previously appeared as too low a fuel level setting was actually very high! However, resetting the floats on the front carb to 15mm then gave me far too low a level again. It seemed I could get levels of 25mm (overflow) or 32mm but nothing really in between. Now the battery has been eliminated as a cause of this variation I had to look elsewhere.
The web guides suggest that in order to check fuel levels (floats out) you should connect the fuel line, energise the system and wait 30 sec for the float bowls to fill. I can say categorically that this doesn't work- certainly not if you are disconnecting the fuel hoses as I have now started to do, because each re-connection introduces air locks into the hoses and these do affect the carb fuel levels even though they probably should not. Its necessary to loosen the fuel pipe-to-carb unions to bleed the air out and bring fuel to the carbs before they will fill properly. Luckily for me the outer casing of my fuel hoses has already fallen off (!) eventually I will recover with "Roundit". However at the moment I can at least monitor fuel flow and airlocks easily. Its probably also a good idea to crank (or preferably run) the motor for a little while if you can before resting it (motor stopped, fuel pump on) for 10-20 seconds to let the levels settle. This will ensure that you get consistent values at each test. However the fact remained that I was still getting fuel levels about 30 mm at a 15mm float setting instead of the expected 27mm.
It was at this point that I happened to notice the droop down distance of the floats seemed to have become rather large. I had become rather obsessed with achieving an exact 15 mm float setting and hadn't appreciated that as I changed this by a variety of tab and arm bending steps I was also altering the float droop. This is controlled by the stop tab at the rear of the float arm yoke. Droop had crept up to around 35mm and in a man of my age excessive droop is never something to be welcomed! To be fair I hadn't really thought that this setting could have any bearing on fuel level and so had paid it little attention. Its tricky to adjust this tab but I managed to bend it inwards and set the droop height back to 25mm as per Mr Hammill's advice. Check floats again, reassemble, retest... Hey presto fuel level now 27.3 mm with floats set at 14.9mm!!! Joy and rapture!! I have no idea how or why the droop distance affects fuel level but my experience here was that it does. So, front carb now behaving!! ****
***Sadly this didnt stand the test of time and in subsequent measurements it reverted to 30.9mm again. I have no idea why, I have even changed the floats and still get the same fuel level. Currently I'm thinking that this must result from performing the determination on a slope. What ever the true fuel level, I am now confident that all floats are set correctly and this level of fuel is sufficient for running.
I have added a summary of how I would do this floats out test in future to my original post on float level adjustment. Its chronologically out of place but might assist anyone who is just looking for a method and doesn't want to go through all of my struggles.
 |
| Float yoke set. Droop adjustment tab at rear, with forked float adjustment tab in front. |
... Joy sadly short lived as I now set about resetting the rear carb. It too had an excessive droop distance and so I set the floats back to as close to 15mm as I could make them and the droop to 25mm. I re-pressurised the fuel, but the fuel level was still low at 30mm despite my best efforts. However on the credit side, with both carbs set up as specified, the motor did start and actually ran rather well after it had settled down. I was able to run it up to temp for the first time and observed a charging voltage, good oil pressure and eventually a water temp reading on the gauge. The thermostat opened and I got water circulation through the heater- thankfully without leakage from my newly repaired hoses although I was unable to confirm whether the otter switch works or not. Furthermore of course, I have no idea how the motor would behave under load but it wasn't all bad news. I'm pleased it was running so well.
My next step was to set the timing with the strobe. Set statically I had achieved 8 deg btdc when tested by strobe. Using the strobe I reset this to 10 deg btdc at idle speed. I had hoped that this would improve running and possibly the fuel drippage problem but sadly this was not the case. If anything the motor runs rougher now than when set at 8 deg btdc. So matters are improved, but I would be deceiving you if I said that the fuel-in-the-trumpet problem was now solved, its not! Although the front carb (apparently with the correct fuel level) looks pretty much cured, there is still fuel visible in both barrels of the rear carburettor suggesting that this carb at least is running very rich. I think the timing change has shown up these defects in carburation so I need to re-address this problem. Given my progress to date, I may be going around this loop for a while!
Tim Engel does mention that although the enrichment devices fail so rarely that there is no description of them in any book or on any site I can find, they can fail occasionally and when they do they can allow excess fuel through. This failure he states is usually down to the "washer"... sadly there is no washer listed on the Dellorto parts diagram in this area, but I believe this is because its usually supplied as part of the choke piston (fitted into the bottom a little like the washer in the piston of a plumbing ballcock valve) so it might be necessary to renew the whole piston.
In order to test the cause of this difference between carbs I swapped carburettor lids/float assemblies. The front carb still ran well but the rear still flooded. I therefore conclude that the flooding problem is not related to float setting or enrichment device, but must be determined by the lower part of the carb.
Currently I am wondering if the anti reversion spacers are fitted correctly (cone towards engine). These spacers reduce backflow of gases from the manifold and such a backflow might push fuel through the overflows and acceleration pump. My blog shows that I had fitted them correctly but can I be sure?
The second thought that occurs to me is to suspect the acceleration pumps themselves. Mr Hammill advised leaving them well alone- so I have (!) but this does assume that they have been set up correctly in the past and I have no guarantee of this. Since the motor has had a very chequered history the pumps may well been "tweaked" to offset some other problem in the past. Since the motor has now been rebuilt and the carbs cleaned and rebuilt, then any such tweaks would now be out of date.
In order to check these points I had to remove the carbs again. Immediately this showed that there was no problem with the spacers, these were indeed correctly installed with the cones pointing in towards the motor.
 |
| Anti-reversion spacers- fitted the right way round! |
 |
| Inlet manifold cylinders 3 and 2 - note excess sootiness around inlet for cylinder 3 (lhs) compared with that for cylinder 2 (rhs). |
I had difficulty in getting my head around the operation of both of these and I have therefore written my own "take" on their operation, servicing and adjustment which I will move to a second post. This at last enabled me to sort out the excess fuel in the trumpets.
Friday 13 January 2017
Carburettors revisited
Apologies Dear reader - I have reworked this entry to try and remove the repetition and improve clarity.
Well having sorted the pedal box and now refitted the dash I was able to try starting the motor again to see the effect of the float level alterations;
The news wasn't good! The car refused to start, at first I suspected ignition failure but this was quickly excluded and I found that the car started perfectly if the carb intakes were treated to a squirt of Bradex Easy Start! This pretty much excluded timing or ignition faults and pointed the finger squarely at fuel supply. Fuel was visible moving along the carb feed tubes, I did add more to the tank as levels were low and the gauge was registering below. I had suspected that the pump might be struggling, but adding more fuel changed nothing. There was nothing for it; I had to revisit the fuel levels in the carbs. I think it will help if I refer to the adjustments that can be made as "clearances"
Float clearance- measured between carburettor top (with gasket) and float top is the gap above the float when the needle valve has shut- smaller this clearance the higher the float (and thus the fuel level the bowl) before the valve shuts.
Fuel clearance- the distance above the fuel to a fixed point in the carb, namely the top of the internal pedestal. The Lower this clearance measurement, the higher is the fuel in the bowl.
To check adjustment I monitored the fuel clearance values using the floats-out method. I removed the choke connections for simplicity and I found that if the fuel inlet pipes are disconnected at the carb after the bowls have been pressurised, pressure is cancelled; excess fuel can be collected in a small container for re-use and and there is very little extra fuel to leak into the bowl from the needle valve as the carb tops are removed. Cumbersome and awkward but it was do-able. Doing the test this way I was much more confident in the results and discovered that the fuel clearances were higher than expected; 30.2 mm in the front carb was as I thought, but that in the rear carb was even higher at 32.8mm, meaning that fuel levels in the bowl were much too low.
Floats were still set at the 15mm clearance value where I had set them when last adjusted. This setting gives much lower fuel than expected and I suspect means that the floats have themselves been bent so that float level no longer correlates even approximately with fuel depth. These low fuel levels appear to be too low to allow the motor to start so I had no choice but to re-visit the adjustment.
The float clearance is set by bending the tab- bending it away from the arm and towards the needle will hold the arm off the valve, depressing the float. This means the valve will close when the float is in a lower position and so increases the measured float clearance. This also means that fuel in the bowl can now close the valve at a lower level so less fuel will be in the bowl; in other words fuel clearance will be increased. Bending the tab towards the needle increases float clearance and increases fuel clearance; it lowers fuel levels and weakens the mixture. Conversely bending the tab away from the needle allows the float to ride higher before the valve is shut- this will mean higher fuel levels are needed before the valve is shut off. Bending the tab away from the needle will decrease float clearance and decrease fuel clearance fuel levels will rise and richen the mixture. BUT the tab can only function in this direction if the tab is the first thing to contact the valve. You cannot raise the float (ie decrease float setting) for ever using the tab. When the tab is bent so far towards the float arm that the arm itself contacts the needle before the tab then further tab adjustment will have no effect. It seems that this will give a minimum float clearance obtainable of around 12mm and in fact applied to both of my carbs. The picture below illustrates the problem as the valve is now closed by the float arm and the tab is no longer making contact.
I adjusted the tabs with a small pair of snipe-nosed pliers to decrease float clearance (raise float) by a few mm to around 12mm with the tabs just in contact with the valve body, and repeated the tests. Very fiddly because the fuel hoses have to be disconnected and reconnected in each check. I was able to obtain higher fuel levels (floats out) of 27.2 mm in the front carb and 26.3 mm in the rear. Float settings that gave this were around 12 mm, again supporting the idea that the float arms may have been bent. This was close enough to the desired fuel level to prompt me to run a starting test and now the motor fired up easily. It tended to race because the new throttle cable wasn't properly adjusted (it needed to be screwed in to the bulkhead to place the adjustment range within the adjustment possibilities of the cam-cover screw adjuster but this was easily done). The motor then ran reasonably well (bearing in mind that it has not been adjusted for dynamic timing).
However, I still have the problem of fuel puddling in the carb throats which I had hoped was solved! I did get a short video of this happening- I should say that I know the motor sounds rough in this video- but its not been set up yet for dynamic timing.-Adjusting the timing may in itself help improve the situation.
This was worse than before! Obviously very disappointing! In the rear carb at least it seems that fuel is now streaming from the acceleration jet as well! This looks like a stuck float in this carb but I need to investigate a bit more.
Update:
Well I have to confess I am totally baffled by these carbs! I remeasured the fuel clearances and found that both were now higher than I had expected from my determinations above. I repeated the tests to get some consistency and both were coming out at 30mm rather than the 26-27mm I had obtained before. I think the difference is due to improved technique (disconnecting the fuel hose before raising the carb lid). This is still too low but its about the maximum adjustment possible on the float arm and I can't decrease float clearance to raise fuel levels (decrease fuel clearance) any further. I checked with Eurocarb that their recommended replacement 170 needle does not require an alteration in float setting. The trouble is my findings have now led me to two mutually incompatible conclusions!
My first problem is that setting the float at 15mm gives me a fuel clearance of 32mm and not the expected 27mm; at this level fuel depth in the bowl is too low for the motor even to run! Resetting them to 12mm clearance (the minimum I can obtain) decreases the fuel clearance to around 30.5 mm. This is still way off the 27mm desired, but it does mean that the fuel depth is raised by 1-2 mm, and at this point the motor will start. I.e. this finding implies that my fuel levels are too low and I have insufficient adjustment in the float to reach the desired fuel clearance value of 27mm.
Secondly, if fuel levels are too low then fuel overflow should not be a problem. In my case turning on the fuel pump and filling the carb bowls is fine- no overflow is evident. However, this brings me to my second problem in that if the motor is actually started and run for a short while, then fuel overflow soon becomes obvious! This implies that fuel levels are now too high!
It doesn't seem likely to me that I could have a fuel levels in both carbs which are both too low and too high at the same time! I've thought about it a lot and maybe the following features might be involved:
1. Perhaps the floats are very bent- disconnecting the expected correlation between float and fuel clearances- although they don't look that way.
2. Perhaps the floats are tending to stick or jam when the engine is running (and therefore vibrating) leading to leakage and overflow when running.
3. Perhaps float buoyancy has been altered such that they don't rise as fast and so do not shut off the needle valve as quickly as they should when the motor is running and rapid valve operation is required. However, if the floats are too heavy then they should float lower in the fuel and fuel levels should be higher at any given float setting not lower.
4. One possibility I have had at the back of my mind (and have been trying to ignore) is that the inlet valves might be leaking allowing gas pressure to pressurise the carb and force fuel from the float chamber through the acceleration pump- although I suspect this wouldn't explain overflow through the venturi.*
5. Ignition timing wrong (and it is!) Trouble is I don't want to set it up with the strobe since I don't want to run it with fuel leaking out!
6. Poor battery failing to run fuel pump to correct pressure unless motor running and alternator supplementing power. This could lead to low fuel levels in my test but higher when running... Seems like a long shot but I will charge it up in case.
I'm not altogether sure if 4 or 5 could be an explanation, and as I'm not anxious to strip the head off again (with its associated gasket costs), I think that at this stage, and given the possibility of bent float arms, I have to try a float swap. The 8.5 g floats aren't available any more from Eurocarb who only stock 7g. Further they are expensive at £42 for each float assembly (plus postage). I was able to find 8.5g floats and save about £20 on the pair by shopping around. I will fit these and re-test all clearance values. Its probably also a good idea to do a compression test and look for leaking valves... possibly even maybe screw up my courage and set the timing...?
* I should add that I did eventually check compression values. Gratifyingly they were all very similar at 175, 175, 172 and 170psi. This similarity means I can probably discard this outside possibility... thank goodness!!
Well having sorted the pedal box and now refitted the dash I was able to try starting the motor again to see the effect of the float level alterations;
The news wasn't good! The car refused to start, at first I suspected ignition failure but this was quickly excluded and I found that the car started perfectly if the carb intakes were treated to a squirt of Bradex Easy Start! This pretty much excluded timing or ignition faults and pointed the finger squarely at fuel supply. Fuel was visible moving along the carb feed tubes, I did add more to the tank as levels were low and the gauge was registering below. I had suspected that the pump might be struggling, but adding more fuel changed nothing. There was nothing for it; I had to revisit the fuel levels in the carbs. I think it will help if I refer to the adjustments that can be made as "clearances"
Float clearance- measured between carburettor top (with gasket) and float top is the gap above the float when the needle valve has shut- smaller this clearance the higher the float (and thus the fuel level the bowl) before the valve shuts.
Fuel clearance- the distance above the fuel to a fixed point in the carb, namely the top of the internal pedestal. The Lower this clearance measurement, the higher is the fuel in the bowl.
To check adjustment I monitored the fuel clearance values using the floats-out method. I removed the choke connections for simplicity and I found that if the fuel inlet pipes are disconnected at the carb after the bowls have been pressurised, pressure is cancelled; excess fuel can be collected in a small container for re-use and and there is very little extra fuel to leak into the bowl from the needle valve as the carb tops are removed. Cumbersome and awkward but it was do-able. Doing the test this way I was much more confident in the results and discovered that the fuel clearances were higher than expected; 30.2 mm in the front carb was as I thought, but that in the rear carb was even higher at 32.8mm, meaning that fuel levels in the bowl were much too low.
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| Testing rear carb fuel level via floats-out method. |
Floats were still set at the 15mm clearance value where I had set them when last adjusted. This setting gives much lower fuel than expected and I suspect means that the floats have themselves been bent so that float level no longer correlates even approximately with fuel depth. These low fuel levels appear to be too low to allow the motor to start so I had no choice but to re-visit the adjustment.
The float clearance is set by bending the tab- bending it away from the arm and towards the needle will hold the arm off the valve, depressing the float. This means the valve will close when the float is in a lower position and so increases the measured float clearance. This also means that fuel in the bowl can now close the valve at a lower level so less fuel will be in the bowl; in other words fuel clearance will be increased. Bending the tab towards the needle increases float clearance and increases fuel clearance; it lowers fuel levels and weakens the mixture. Conversely bending the tab away from the needle allows the float to ride higher before the valve is shut- this will mean higher fuel levels are needed before the valve is shut off. Bending the tab away from the needle will decrease float clearance and decrease fuel clearance fuel levels will rise and richen the mixture. BUT the tab can only function in this direction if the tab is the first thing to contact the valve. You cannot raise the float (ie decrease float setting) for ever using the tab. When the tab is bent so far towards the float arm that the arm itself contacts the needle before the tab then further tab adjustment will have no effect. It seems that this will give a minimum float clearance obtainable of around 12mm and in fact applied to both of my carbs. The picture below illustrates the problem as the valve is now closed by the float arm and the tab is no longer making contact.
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| Non adjustable float shown with the carb top in the near vertical position in which float height is adjusted. Float arm hinge uppermost, float arm to right. Forked adjustment tab below arm engaged with the narrow spring loaded section of the needle protruding from the needle shoulder. The needle is seated by the float arm itself and the tab is not controlling float setting. This means that 12mm is the minimum float setting obtainable. |
However, I still have the problem of fuel puddling in the carb throats which I had hoped was solved! I did get a short video of this happening- I should say that I know the motor sounds rough in this video- but its not been set up yet for dynamic timing.-Adjusting the timing may in itself help improve the situation.
This was worse than before! Obviously very disappointing! In the rear carb at least it seems that fuel is now streaming from the acceleration jet as well! This looks like a stuck float in this carb but I need to investigate a bit more.
Update:
Well I have to confess I am totally baffled by these carbs! I remeasured the fuel clearances and found that both were now higher than I had expected from my determinations above. I repeated the tests to get some consistency and both were coming out at 30mm rather than the 26-27mm I had obtained before. I think the difference is due to improved technique (disconnecting the fuel hose before raising the carb lid). This is still too low but its about the maximum adjustment possible on the float arm and I can't decrease float clearance to raise fuel levels (decrease fuel clearance) any further. I checked with Eurocarb that their recommended replacement 170 needle does not require an alteration in float setting. The trouble is my findings have now led me to two mutually incompatible conclusions!
My first problem is that setting the float at 15mm gives me a fuel clearance of 32mm and not the expected 27mm; at this level fuel depth in the bowl is too low for the motor even to run! Resetting them to 12mm clearance (the minimum I can obtain) decreases the fuel clearance to around 30.5 mm. This is still way off the 27mm desired, but it does mean that the fuel depth is raised by 1-2 mm, and at this point the motor will start. I.e. this finding implies that my fuel levels are too low and I have insufficient adjustment in the float to reach the desired fuel clearance value of 27mm.
Secondly, if fuel levels are too low then fuel overflow should not be a problem. In my case turning on the fuel pump and filling the carb bowls is fine- no overflow is evident. However, this brings me to my second problem in that if the motor is actually started and run for a short while, then fuel overflow soon becomes obvious! This implies that fuel levels are now too high!
It doesn't seem likely to me that I could have a fuel levels in both carbs which are both too low and too high at the same time! I've thought about it a lot and maybe the following features might be involved:
1. Perhaps the floats are very bent- disconnecting the expected correlation between float and fuel clearances- although they don't look that way.
2. Perhaps the floats are tending to stick or jam when the engine is running (and therefore vibrating) leading to leakage and overflow when running.
3. Perhaps float buoyancy has been altered such that they don't rise as fast and so do not shut off the needle valve as quickly as they should when the motor is running and rapid valve operation is required. However, if the floats are too heavy then they should float lower in the fuel and fuel levels should be higher at any given float setting not lower.
4. One possibility I have had at the back of my mind (and have been trying to ignore) is that the inlet valves might be leaking allowing gas pressure to pressurise the carb and force fuel from the float chamber through the acceleration pump- although I suspect this wouldn't explain overflow through the venturi.*
5. Ignition timing wrong (and it is!) Trouble is I don't want to set it up with the strobe since I don't want to run it with fuel leaking out!
6. Poor battery failing to run fuel pump to correct pressure unless motor running and alternator supplementing power. This could lead to low fuel levels in my test but higher when running... Seems like a long shot but I will charge it up in case.
I'm not altogether sure if 4 or 5 could be an explanation, and as I'm not anxious to strip the head off again (with its associated gasket costs), I think that at this stage, and given the possibility of bent float arms, I have to try a float swap. The 8.5 g floats aren't available any more from Eurocarb who only stock 7g. Further they are expensive at £42 for each float assembly (plus postage). I was able to find 8.5g floats and save about £20 on the pair by shopping around. I will fit these and re-test all clearance values. Its probably also a good idea to do a compression test and look for leaking valves... possibly even maybe screw up my courage and set the timing...?
* I should add that I did eventually check compression values. Gratifyingly they were all very similar at 175, 175, 172 and 170psi. This similarity means I can probably discard this outside possibility... thank goodness!!
Wednesday 11 January 2017
Progress is a great thing- wish I had some.
This one is more of a diary entry than anything too technical. The weather is set to deteriorate in the UK this week. Its likely to get colder, snow even down here in the South and its getting increasingly hard to force my aging frame in, around and under the car. However, I have been doing a few little things; I have been trying to sort out the carpets (now the pedal box was back in) and also to test the effect of my carburettor float height settings now that the dash is back in and I can try to start the motor. I have added a new post on carburettors revisited and updated my post:
-but basically the motor wouldn't start at all with the new float settings and I needed to fiddle about a lot to get it to run... and I still have overflow problems! If interested you can read the relevant post (above) but I'm feeling a bit frustrated at the moment and have retired to wait out the cold snap!
However on the upside I think I must be near a milestone now- the motor does run and now that the clutch seems to move I may be able to actually move the car under its own power- something that hasn't happened certainly for 10 and possibly not for 20 years! All the same- any restoration project has low spots and the frustration of the carbs coupled with the poor weather means that I have hit one low spot big time! I am starting to look at MGBs...
-but basically the motor wouldn't start at all with the new float settings and I needed to fiddle about a lot to get it to run... and I still have overflow problems! If interested you can read the relevant post (above) but I'm feeling a bit frustrated at the moment and have retired to wait out the cold snap!
However on the upside I think I must be near a milestone now- the motor does run and now that the clutch seems to move I may be able to actually move the car under its own power- something that hasn't happened certainly for 10 and possibly not for 20 years! All the same- any restoration project has low spots and the frustration of the carbs coupled with the poor weather means that I have hit one low spot big time! I am starting to look at MGBs...
Sunday 8 January 2017
Lucas YXB135 ignition (igniter) module tester
Hi All- followers of this blog may recall that I recently had the joyous experience of tracing an intermittent ignition fault. Although this was ultimately due to a duff ignition switch I got confused, as I had swapped the DAB125 module inside the AB14 as a first step in order to eliminate this as a fault. Sad to say the new Intermotor module I had used was actually faulty itself and this stopped me from solving the problem by changing the switch. When I eventually refitted the old module all was well.
I wanted to avoid a recurrence and although I did get a testing protocol for these modules eventually, I also found that Lucas had produced a dedicated module tester the YWB135 which can test a whole variety of modules.
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| YWB135 Lucas module tester |
This seemed really useful so when one of these came up on Ebay I grabbed it. However caveat emptor clearly applied, and although the unit did come with an instruction booklet, the description failed to mention that in fact there should be 2! I am lacking the red covered book which contains the operating instructions, test procedures and how to interpret the results.
Well I did eventually get the instructions and I'm greatly indebted to Bos Automaterialen of the Netherlands for copying a booklet he had in stock- at no charge! You dont get service like that very often these days! Anyway Many thanks Bos! If anyone would like to visit/like his facebook page you will find it here.
Just in case anyone is curious (and for backup purposes) I'm posting the pics here:
Well I did eventually get the instructions and I'm greatly indebted to Bos Automaterialen of the Netherlands for copying a booklet he had in stock- at no charge! You dont get service like that very often these days! Anyway Many thanks Bos! If anyone would like to visit/like his facebook page you will find it here.
Just in case anyone is curious (and for backup purposes) I'm posting the pics here:
Great to say the module I have fitted passed the test, the "new" Intermotor part I had bought previously failed. I ordered another from China at only £12 I wasn't too confident and I've not tested it in the car yet, but I did put it through the meter test and it passed fine! I will keep this one as a spare.
Saturday 7 January 2017
Adjusting the clutch...
Well constant reader, you will recall that my first attempts to adjust the clutch led to the grim discovery of a bent pedal box. Having now changed that its time to revisit clutch adjustment. Overall a worry that I hope turned out to be nothing at all- does owning a Lotus induce paranoia? I suspect so.
As summarised before the WM shows only two adjustments need to be made to the clutch; the slave cylinder push rod is adjusted so that full travel is achieved just as the pedal reaches the carpet during depression- and there is a pedal upstop that should be adjusted such that there is around 1 cm free play when the pedal is in the "up" position. In other words the distance that it can be pushed without significant resistance before it starts to move the clutch. This free play ensures that the clutch isn't being pre-loaded by the pedal. This puzzled me greatly because adjustment of the up stop itself cannot actually create this free play- it can only limit it. This is because the push rod is metal and doesn't stretch! If you set the pedal to max push rod movement at the pedal down stroke, then since the push rod is of fixed length then the "up" position must also be fixed. Further the amount of free play obtainable is limited to the amount the push rod can move between contacting the piston inside the M/C (forward), and jamming on the stop washer (rearwards). This free play is already detectable in an isolated master cylinder independently of pedal connection. All the pedal up-stop can do is reduce this to a target of about 1-1.5 cm.
The problem I had was that even with the new pedal box, adjustment is still not obvious by these guidelines and if anyone has more insight I'd be pleased to hear.
Firstly, I found that the MC push rod needed to be adjusted to its shortest possible length in order to bottom out near the carpet- in fact if the goal is at the carpet, then the push rod just isn't short enough!
Secondly, when the push rod is adjusted to this length, then the pedal doesn't move back up far enough to contact the up-stop at all! Its upward travel is limited by the length of the push rod and available end play in the MC. This means that the pedal return spring is effectively always pulling on the push rod which I don't think can be a good situation. I messed about with these adjustments for a while before deciding that what is going to matter ultimately is the operation of the clutch. This means setting a convenient pedal height and achieving smooth dis/re-engagement without binding when its depressed. Disengagement is likely to occur before full depression of the pedal anyway. This can only be checked as a running adjustment when the car is mobile; so I wound the push rod back out enough that the pedal contacts the up-stop bolt to take the strain of the MC, and decided to shelve the adjustment and tackle it again if/when the car can move.
I also attempted to bleed the clutch system. This would be easy if I had a helper, but working on my own I cannot check the exiting fluid for bubbles at the same time as pressing the pedal to expel the fluid. I decided therefore to use a vacuum bleeder, and although this was successful, it was difficult to be certain when bleeding had been achieved because air was obviously leaking in through the threads of the loosened bleed nipple and creating bubbles in the vacuum pump tubing. Once I realised this was happening I resorted to bleeding using my old Castrol bleed system; a one way valve on a tube I had bought back in the 70s! Surprisingly it still works.
At this point I got a nasty shock as the slave push-rod was not in firm contact with the clutch operating arm. The operating arm appeared to be able to flop fore and aft through a movement of around 5 cm. The slave push-rod is only app 7 cm long so this was obviously worrying, and the movement was such that the arm could be pushed back and the slave cylinder push-rod disengaged from it entirely! Looking back I'm not sure why, but I had expected the operating arm to be sprung firmly forwards against the slave push-rod by the clutch springs pushing the CRB backwards (and thus the release arm forwards).
I spent a worrying night considering how the arm could have detached from either the release bearing or the pivot point, and fretting that a gearbox or engine removal would be needed.
However the forum was reassuring- and some members provided pictures of their own release arms in position. The next morning more thought had alleviated the worry a little: Since some cars actually have a modification in that a rearward acting assist spring is installed, it can't be that the actuating arm is always sprung forwards. The reasons for this modification seem to include assisting the push-rod in moving a very heavy clutch but also reducing noise caused by the actuating arm moving about. This has to mean that a certain amount of play in the lever is to be expected and it seems that if anything, the lever should be pulled away from the push-rod. My car wasn't fitted with a clutch arm return spring, and there is no trace of the fixing bracket suggesting that it never was. The modification seems to have been made as and when it was needed. I also found that the next day the slave push-rod was now against the release arm I think it might extend gradually on its own (under gravity?) or through my attempts at bleeding. Anyway, the operating arm was now fully back on the outside (i.e. fully forward against the clutch springs on the inside) and couldn't be pushed backwards by hand against the clutch spring. In this position the operating arm was app 4 cm from the rear of the slave cylinder and 13 cm from the front end by the bleed nipple. Access/visibility was pretty hard-to-impossible but I did get a couple of images from an endoscope.
This was a pretty similar position to that shown in the pictures on the forum. Roping in an assistant, I was able to determine that the operating arm was moving backwards when the clutch was depressed; and returning when it was released! This is all boding well for a running adjustment later when I can check if the clutch is disengaging for a smooth gearchange.
Thinking about this whole situation I think the problem was really one of simply having the wrong expectations; I had expected the clutch arm to be sprung forwards on the outside of the bell-housing but in fact its loose and floppy, and if anything, it may need to be held backwards. This being the case my clutch is probably OK: Cue massive sigh of relief... Mine's a pint!
As summarised before the WM shows only two adjustments need to be made to the clutch; the slave cylinder push rod is adjusted so that full travel is achieved just as the pedal reaches the carpet during depression- and there is a pedal upstop that should be adjusted such that there is around 1 cm free play when the pedal is in the "up" position. In other words the distance that it can be pushed without significant resistance before it starts to move the clutch. This free play ensures that the clutch isn't being pre-loaded by the pedal. This puzzled me greatly because adjustment of the up stop itself cannot actually create this free play- it can only limit it. This is because the push rod is metal and doesn't stretch! If you set the pedal to max push rod movement at the pedal down stroke, then since the push rod is of fixed length then the "up" position must also be fixed. Further the amount of free play obtainable is limited to the amount the push rod can move between contacting the piston inside the M/C (forward), and jamming on the stop washer (rearwards). This free play is already detectable in an isolated master cylinder independently of pedal connection. All the pedal up-stop can do is reduce this to a target of about 1-1.5 cm.
The problem I had was that even with the new pedal box, adjustment is still not obvious by these guidelines and if anyone has more insight I'd be pleased to hear.
Firstly, I found that the MC push rod needed to be adjusted to its shortest possible length in order to bottom out near the carpet- in fact if the goal is at the carpet, then the push rod just isn't short enough!
Secondly, when the push rod is adjusted to this length, then the pedal doesn't move back up far enough to contact the up-stop at all! Its upward travel is limited by the length of the push rod and available end play in the MC. This means that the pedal return spring is effectively always pulling on the push rod which I don't think can be a good situation. I messed about with these adjustments for a while before deciding that what is going to matter ultimately is the operation of the clutch. This means setting a convenient pedal height and achieving smooth dis/re-engagement without binding when its depressed. Disengagement is likely to occur before full depression of the pedal anyway. This can only be checked as a running adjustment when the car is mobile; so I wound the push rod back out enough that the pedal contacts the up-stop bolt to take the strain of the MC, and decided to shelve the adjustment and tackle it again if/when the car can move.
I also attempted to bleed the clutch system. This would be easy if I had a helper, but working on my own I cannot check the exiting fluid for bubbles at the same time as pressing the pedal to expel the fluid. I decided therefore to use a vacuum bleeder, and although this was successful, it was difficult to be certain when bleeding had been achieved because air was obviously leaking in through the threads of the loosened bleed nipple and creating bubbles in the vacuum pump tubing. Once I realised this was happening I resorted to bleeding using my old Castrol bleed system; a one way valve on a tube I had bought back in the 70s! Surprisingly it still works.
At this point I got a nasty shock as the slave push-rod was not in firm contact with the clutch operating arm. The operating arm appeared to be able to flop fore and aft through a movement of around 5 cm. The slave push-rod is only app 7 cm long so this was obviously worrying, and the movement was such that the arm could be pushed back and the slave cylinder push-rod disengaged from it entirely! Looking back I'm not sure why, but I had expected the operating arm to be sprung firmly forwards against the slave push-rod by the clutch springs pushing the CRB backwards (and thus the release arm forwards).
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| Push-rod removed from my old slave cylinder- app 7cm. |
However the forum was reassuring- and some members provided pictures of their own release arms in position. The next morning more thought had alleviated the worry a little: Since some cars actually have a modification in that a rearward acting assist spring is installed, it can't be that the actuating arm is always sprung forwards. The reasons for this modification seem to include assisting the push-rod in moving a very heavy clutch but also reducing noise caused by the actuating arm moving about. This has to mean that a certain amount of play in the lever is to be expected and it seems that if anything, the lever should be pulled away from the push-rod. My car wasn't fitted with a clutch arm return spring, and there is no trace of the fixing bracket suggesting that it never was. The modification seems to have been made as and when it was needed. I also found that the next day the slave push-rod was now against the release arm I think it might extend gradually on its own (under gravity?) or through my attempts at bleeding. Anyway, the operating arm was now fully back on the outside (i.e. fully forward against the clutch springs on the inside) and couldn't be pushed backwards by hand against the clutch spring. In this position the operating arm was app 4 cm from the rear of the slave cylinder and 13 cm from the front end by the bleed nipple. Access/visibility was pretty hard-to-impossible but I did get a couple of images from an endoscope.
 |
| Slave cylinder to actuating arm. You can just see that the distance with the arm pressed backwards (ie forwards against the clutch in the bell housing) is app 4 cm from lever to the groove in the slave cylinder that locates the rubber end boot. |
This was a pretty similar position to that shown in the pictures on the forum. Roping in an assistant, I was able to determine that the operating arm was moving backwards when the clutch was depressed; and returning when it was released! This is all boding well for a running adjustment later when I can check if the clutch is disengaging for a smooth gearchange.
Thinking about this whole situation I think the problem was really one of simply having the wrong expectations; I had expected the clutch arm to be sprung forwards on the outside of the bell-housing but in fact its loose and floppy, and if anything, it may need to be held backwards. This being the case my clutch is probably OK: Cue massive sigh of relief... Mine's a pint!
Tuesday 3 January 2017
Lotus Excel Pedal box 4: how I would remove it now!
Well the job of removing and replacing the pedal box has taken me four days! Most of this was caused by backtracking, redoing things I had done wrongly and simply trying to find a more effective way to reach the offending fittings! So here is a short summary of how I would do the job if ever (heaven forbid) I have to do this job again! The following applies to the early cars which have a bracing system that attaches only to the steering column. Have a look at my various posts on removing and refitting the pedal box for illustrations.
1. Remove the steering column shrouds (1 screw either side two at front) Don't unscrew the central screw in the base of the bottom section.
2. Remove the instrument panel trim plate and then the 4 self-tapping screws that hold the panel on, and pull the whole dashpod forward off its two retaining posts.
3. As the panel comes forward disconnect the speedo cable (on these early cars its a clip fastening).
4. Reaching in through the dash panel opening, remove the two relays and using a flexible screwdriver remove the relay block mounting screws; pull the footwell heater ducting out of the pedal box.
5. From underneath remove the wiper delay module and disconnect the brake switch and cables from the earthing post.
6. Detach the brake and clutch M/C pushrods by removing the R clips and withdrawing their clevis pins. Leave the throttle cable attached at this stage.
7. Detach the throttle cable at the carburettor end.
8. Remove the central knee pad trim to expose the steering column mountings; there are three of these. The front two screw into captive spacers. Remove the third using an 18mm stubby spanner to hold the loose nut from above and a 16mm socket on the bolt head below.
9. Preferably using a helper, hold the heads of the two bolts that penetrate through the top of the pedal box and emerge inside the engine bay (one bolt is below the heater air intake scuttle). Use 1/4 inch drive sockets on a wobble bar extn to reach the bolts from the underside.
10. Remove the brake master cylinder and then from inside the car remove the 4 servo retaining nuts using a 1/4 drive socket, UJ and extension rods. Remove the servo. Removing the clutch MC may also help.
11. The pedal box is now free, tip it down at the bulkhead side so that the steering column end rises, then slip the box to the right to clear the steering column and pull the box downwards. Do not pull too far as the throttle cable will limit the movement possible.
12. Reach around the box and detach the throttle cable by sliding it across the trunnion and down the slot so that the nipple is released through the keyhole. This should be achieved by sliding the cable to the right; but I have come across cars where movement to the left is necessary. The box is heavy with an awkward weight distribution; You may need a partner to support it through the the servo hole from outside the car.
13. When the box is out, I recommend that you check that the throttle cable trunnion has its keyhole opening on the right of the box- i.e. positioned towards the outside of the box and not facing towards the brake pedal.
Refitting is the reverse but note:
1. Use masking tape to secure the box spacers to the front two column mounting points; if your box had the bar spacer at the rear, tape that in position too.
2. Refit the throttle cable to the trunnion before positioning the box over the steering column. It can be done later (see below) but its best done before the box obstructs access.
3. Use screwdriver podgers to align the holes in the spacers with the bolt holes in the column mounts or bulkhead.
4. If you refit the cable after fitting the box (or if you are changing the cable) fit the new cable into the keyhole by poking the ball end into the keyhole and slipping it upwards. Snipe nosed pliers should help but beware; access is tricky- and impossible if the keyhole is positioned towards the brake pedal.
5. Ensure that the trunnion yokes on the brake servo and clutch MC pushrods locate over their respective pedals as these are refitted.
6. If (who am I kidding- "When") you have trouble offering up the clevis pins to the trunnions mount them sideways across the end of a magnetic pickup tool and offer them up to the hole in the trunnions that way- easing them in from the side either with a finger if possible, or the flat bladed side of a screwdriver.
7. Use bolt or screwdriver podgers to align the servo holes in the pedal box with those in the body before refitting the brake servo.
If you are replacing the box make sure that the self-tapping screws that attach the relay block and wiper module do actually fit and tighten easily, also that the earthing post thread isn't stripped. If not select appropriate screws or drill out the holes and chase the thread if needed before fitting the pedal box as its awkward to do this later.
1. Remove the steering column shrouds (1 screw either side two at front) Don't unscrew the central screw in the base of the bottom section.
2. Remove the instrument panel trim plate and then the 4 self-tapping screws that hold the panel on, and pull the whole dashpod forward off its two retaining posts.
3. As the panel comes forward disconnect the speedo cable (on these early cars its a clip fastening).
4. Reaching in through the dash panel opening, remove the two relays and using a flexible screwdriver remove the relay block mounting screws; pull the footwell heater ducting out of the pedal box.
5. From underneath remove the wiper delay module and disconnect the brake switch and cables from the earthing post.
6. Detach the brake and clutch M/C pushrods by removing the R clips and withdrawing their clevis pins. Leave the throttle cable attached at this stage.
7. Detach the throttle cable at the carburettor end.
8. Remove the central knee pad trim to expose the steering column mountings; there are three of these. The front two screw into captive spacers. Remove the third using an 18mm stubby spanner to hold the loose nut from above and a 16mm socket on the bolt head below.
9. Preferably using a helper, hold the heads of the two bolts that penetrate through the top of the pedal box and emerge inside the engine bay (one bolt is below the heater air intake scuttle). Use 1/4 inch drive sockets on a wobble bar extn to reach the bolts from the underside.
10. Remove the brake master cylinder and then from inside the car remove the 4 servo retaining nuts using a 1/4 drive socket, UJ and extension rods. Remove the servo. Removing the clutch MC may also help.
11. The pedal box is now free, tip it down at the bulkhead side so that the steering column end rises, then slip the box to the right to clear the steering column and pull the box downwards. Do not pull too far as the throttle cable will limit the movement possible.
12. Reach around the box and detach the throttle cable by sliding it across the trunnion and down the slot so that the nipple is released through the keyhole. This should be achieved by sliding the cable to the right; but I have come across cars where movement to the left is necessary. The box is heavy with an awkward weight distribution; You may need a partner to support it through the the servo hole from outside the car.
13. When the box is out, I recommend that you check that the throttle cable trunnion has its keyhole opening on the right of the box- i.e. positioned towards the outside of the box and not facing towards the brake pedal.
Refitting is the reverse but note:
1. Use masking tape to secure the box spacers to the front two column mounting points; if your box had the bar spacer at the rear, tape that in position too.
2. Refit the throttle cable to the trunnion before positioning the box over the steering column. It can be done later (see below) but its best done before the box obstructs access.
3. Use screwdriver podgers to align the holes in the spacers with the bolt holes in the column mounts or bulkhead.
4. If you refit the cable after fitting the box (or if you are changing the cable) fit the new cable into the keyhole by poking the ball end into the keyhole and slipping it upwards. Snipe nosed pliers should help but beware; access is tricky- and impossible if the keyhole is positioned towards the brake pedal.
5. Ensure that the trunnion yokes on the brake servo and clutch MC pushrods locate over their respective pedals as these are refitted.
6. If (who am I kidding- "When") you have trouble offering up the clevis pins to the trunnions mount them sideways across the end of a magnetic pickup tool and offer them up to the hole in the trunnions that way- easing them in from the side either with a finger if possible, or the flat bladed side of a screwdriver.
7. Use bolt or screwdriver podgers to align the servo holes in the pedal box with those in the body before refitting the brake servo.
If you are replacing the box make sure that the self-tapping screws that attach the relay block and wiper module do actually fit and tighten easily, also that the earthing post thread isn't stripped. If not select appropriate screws or drill out the holes and chase the thread if needed before fitting the pedal box as its awkward to do this later.
Lotus Excel pedal box 3: post Xmas return reconnecting controls
Well a belated Happy Christmas and a Happy New Year to my follower and of course all/any readers. I hope Santa brought you whatever you need to finish your own Lotuses. Sadly in my case it was pants and socks... necessary and very welcome but not furthering my resto directly! Anyway, after 2 weeks of "family duty" its time to return to the car and finish the installation of the pedal box. Jobs still outstanding are fit the last steering column bolt and tighten all 3; clean, grease and install speedo cable and dashpod; reconnect all 3 pedals; adjust all controls; refill cooling system and bleed brakes and clutch. - All assuming that no new problems emerge and I never did manage to bleed the rear brakes so more work likely to be found there!
I inserted the remaining steering column nut and bolt; this was if you remember a non-caged nut that was free to turn as the bolt is tightened. Since the nut is a nyloc, it tightens onto the bolt even before its hard against the mounting and as the bolt is I think, too long, this means the bolt is free to flap about making holding the invisible nut with a spanner in a confined space very tricky. I therefore swapped the nyloc for a plain nut which could be screwed all the way down by hand and inserted a spring washer below the bolt head to try and put some tension on the bolt and resist any tendency to unscrew. I don't think this is likely given the position, but it made fitting and tightening the bolt really simple. Finally I tightened all the column bolts up.
Reconnecting the throttle cable was a real bitch- I think it would have been easier if the throttle cable yoke/trunnion had been fitted with the keyhole opening to the right as you view it from the driver's seat (ie facing towards the side of the car). I think it would be slightly easier to insert the cable nipple from the outside of the pedal box; as it was I had fitted the yoke the other way around (this was the way I found it on the new pedal box- see my blog on refitting the box and its ancillaries) and opposite to the way my original trunnion had been fitted (see my blog on removal of the box). Since I had one fitted one way round and one the other I took pot luck, and matched the fitting in the box I was going to install- but I think I got it wrong. Access is simply too restricted to permit you to push the cable through the trunnion keyhole from inside the box. After three hours I gave up and decided I had to remove the whole trunnion again- At least I had fitted this with an R clip so it was comparatively easy using a pair of snipe-nosed pliers to pull this out and remove the clevis. I flipped the trunnion over so that the keyhole was towards the right (ie towards the nearest side of the car) as this will help I think in future, but as the trunnion was now free I inserted the cable while it was off. This cable nipple is a split bullet- the rounded end goes through the hole in the trunnion and the barrel section sits outside. The trunnion itself fits into a groove in the nipple so that it can transmit both pull and push demands. (This can be seen in my blog on removing the pedal box).
Of course refitting the trunnion and its clevis was again tricky: It wasn't possible to position the clevis as you really need fingers like an Aye aye - mine were just an inch or so too short- plus I lacked the second opposable thumb evolved by most long term Lotus mechanics! Anyway after an hour I hit upon using a magnetic retrieval tool to hold the clevis. As this is very slim it can slip up inside the box beside the crush of pedal shafts and offer it up to the trunnion once that had been safely hooked over the throttle pedal. I could then push the clevis through. It took a couple of attempts but this was much better than straining to get my arms in far enough and allowed me to rest my bleeding stumps.
The R clip was likewise attached to the magnetic tool and positioned on the clevis. The clip was then pushed home using a steel punch held in the other hand. Once I had adopted the mag tool approach it took only 30 min to connect the cable.
I reattached the throttle cable at the carb end and while I was there I also reconnected the choke- possibly prematurely as I don't know for certain that I will not need to remove the carb tops again! While I was doing that I noticed several cracks in the outer cable. The wound inner case was intact so I covered these with heat shrink tubing to keep the damp out.
In contrast to the problems with the throttle, it was the work of but 5 mins to connect the clutch push rod to the pedal- the alignment was perfect: Since this was the reason I had needed to start this whole horrible pedal box process, I'm very pleased with the result.
The brake servo push rod took slightly longer but wasn't too difficult. It was a bit fiddly to get the holes in the trunnion and pedal to align, but I positioned the clevis pin on the mag tool and pushed it through the trunnion and pedal using a screwdriver blade. The R clip was relatively easily fitted using snipe nosed pliers.
I re-positioned the heater ducting so that it ran back through the pedal box to where it will eventually connect with the vent in the dash bottom panel. I was then able to push the dashpod back into place locating it over the two (left and right) studs and securing it with the 4 instrument panel screws. This was also a bit fiddly as its hard to get the electrics etc back correctly so that the instrument panel can slide back into the pod. However the ducting was the main problem (see above) and after much fiddling the panel eventually slid home. I then refitted the centre console (two screws in the tray) and gear gaiter section.
I still have to adjust the pedals but hey- this completes the whole circle-of-Lotus and gets me back to where I thought I was about a month ago when I found the clutch pedal action was so dodgy! I will add more about the adjustment - and maybe a few extra pics if I can remember to take them but hopefully now its onward and upward!
I inserted the remaining steering column nut and bolt; this was if you remember a non-caged nut that was free to turn as the bolt is tightened. Since the nut is a nyloc, it tightens onto the bolt even before its hard against the mounting and as the bolt is I think, too long, this means the bolt is free to flap about making holding the invisible nut with a spanner in a confined space very tricky. I therefore swapped the nyloc for a plain nut which could be screwed all the way down by hand and inserted a spring washer below the bolt head to try and put some tension on the bolt and resist any tendency to unscrew. I don't think this is likely given the position, but it made fitting and tightening the bolt really simple. Finally I tightened all the column bolts up.
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| Original bolt, washer and nyloc changed for... |
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| Plain nut and spring washer above original washer |
Of course refitting the trunnion and its clevis was again tricky: It wasn't possible to position the clevis as you really need fingers like an Aye aye - mine were just an inch or so too short- plus I lacked the second opposable thumb evolved by most long term Lotus mechanics! Anyway after an hour I hit upon using a magnetic retrieval tool to hold the clevis. As this is very slim it can slip up inside the box beside the crush of pedal shafts and offer it up to the trunnion once that had been safely hooked over the throttle pedal. I could then push the clevis through. It took a couple of attempts but this was much better than straining to get my arms in far enough and allowed me to rest my bleeding stumps.
 |
| Clevis pin held on magnet prior to introducing it up beside the trunnion on the throttle pedal- trunnion shown here for illustration. |
The R clip was likewise attached to the magnetic tool and positioned on the clevis. The clip was then pushed home using a steel punch held in the other hand. Once I had adopted the mag tool approach it took only 30 min to connect the cable.
I reattached the throttle cable at the carb end and while I was there I also reconnected the choke- possibly prematurely as I don't know for certain that I will not need to remove the carb tops again! While I was doing that I noticed several cracks in the outer cable. The wound inner case was intact so I covered these with heat shrink tubing to keep the damp out.
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| Choke cable; cracks covered in heat shrink |
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| Clutch MC push rod trunnion secured to pedal extension using clevis and R clip- note pedal pulls in line with pushrod now! |
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| Brake servo push rod attached via clevis through trunnion. Servo boot to left. |
I cleaned and applied corrosion block grease lightly to the end of the speedo cable before re-clipping this onto the back of the speedometer.
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| Speedo cable end cleaned and v lightly greased... |
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| ... and refitted to the rear of the speedo. |
I still have to adjust the pedals but hey- this completes the whole circle-of-Lotus and gets me back to where I thought I was about a month ago when I found the clutch pedal action was so dodgy! I will add more about the adjustment - and maybe a few extra pics if I can remember to take them but hopefully now its onward and upward!
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