Cooling system; radiator and mounting brackets.

I am having to wait a while for the company to fit in the crank work so in the meantime I will get on with a few bits and pieces. I think you will recall that I have fitted a recon water pump?
Anyway I took the radiator and oil cooler down to Guildford radiators (Cranleigh branch) to be checked.
I also detached the overflow tank and found its spigot was badly corroded- no way I can attach a new pipe there, so I took that as well.

Overflow/header tank removed- three bolts from inside wheel arch. Spigot doesnt look too bad here...

... but viewed from the other side its rusted through and what remains is very thin.

 The total bill for all this (see below) was £66 inc VAT.  I was expecting about half this because a good used header tank is only £30 from Lotus bits and the spigot turned out to be the only work needed. However  this boiled down to one hrs labour so I guess its about right. I really wish I got £66 for every hour I've been putting into this project!


Oil cooler was checked and found to be fine- it was returned to me in a cleaned up state that was most satisfactory.

The guys there also fixed the header tank by welding on a new section with a new spigot. It was repainted as well and acquired a nice new sticker!

The radiator unfortunately turned out to be totally blocked. I was quoted £270 plus VAT to fit 2 new cores. There is a Chinese version on Ebay at £197 outright (not an exchange) but I don't know anything about this. I have bought a rad from China previously for my bike. It wasn't quite the same as the original and although it worked, it was tricky to fit so I didn't fancy a repeat of that on a larger scale. I would love to hear from anyone who has tried the Chinese version but I opted to get an original. Anyway,  I got a reconditioned (and upgraded) three core radiator from Lotus bits. This was £240 including VAT and delivery and should improve cooling... if the motor ever fires up that is!

Lovely new three core rad from Lotus bits.

 The new radiator didn't come with mounting brackets so I had drilled out the pop rivets to save all 4 from my old rad before I sent it back. These are held on by 4 rivets each in the front two holes of the series of three at each corner.

Drilling out the pop rivets from the mounting brackets- this one overhangs the rad at the corners but I cant recall if they all did. Sadly my camera ran out of charge here and so I didn't get pictures.

After de-rusting, three of my brackets were fine and one a bit dodgy- all were serviceable though and if I need a new one then they are £5.50 each plus the usual add-ons from SJS. .... Sadly however I can't use any of them! It turns out that the new radiator is the more up-to-date and wide-bodied form. Brackets for this type are more than double the price at £12.50 each  for some reason- and as I would need 4 this is exhorbitant. I decided to make them:

The new rad is 5cm thick inside the top and bottom channels and the brackets need a 1cm up-stand on each side. I decided to make them 6cm long so making one for a spare means I needed metal at 30 x 7cm.

I scribed a 30 x 7cm rectangle on sheet metal

Cut this out with aviation snips and flattened it, scribing a fold line 1cm from each side

I dont have a sheet metal brake so I formed the up-stand in stages by hammering it in the vise...

... on both sides to make a channel. Lucky this is the wider section as the narrow one would be possible in this size vise!

Check fit- a little high but I can cut the up-stands down

Cut to length.

The originals were fitted with M6 weld bolts positioned on the centre line and drilled 0.75 cms from one end. As this rad is thicker, not lot longer, I'm assuming that this is where the new bolts will need to go as well. Checking the pics on the SJS website supports this idea. I drilled 5.5mm holes in this position and was able the self-thread M6 bolts through these. I welded these in place before cleaning the brackets and spraying them in grey zinc primer and finally in gloss black.

Bolts welded in place. Sprayed in zinc primer
However its hard to be certain where the pop rivet holes should go before the radiator box is in position so I need to refit that. Even new brackets have to be drilled so I suspect this can only be done accurately in position.

I remembered to reconnect the compressor hose to the air horns and The new crash panels weren't in the way but refitting the radiator box upper section was surprisingly tricky: It was difficult to pop the front of the tray back under the bottom of the nose at the front of the car. Eventually I found the way was to get it in position and then hit it sharply at the front with the side of my fist to pop it under the nose. It then pushed back easily and fitted nicely against the new panels at the sides and the top of the air intake mesh at the front.

Radiator box upper section clipped into nose and rests above low level air grill. My new fibreglassing fills in the strange and apparently functionless rubber grommet holes.

Coil of wires under nose, unfastened and brought forward. I cant remember what these serve- or even if they were u in use when I stripped the rad!!

I also found some coiled wires and a surprise tube (with what looks like an in-line brass valve) under the top of the nose (i.e. in front of the radiator). I don't know/can't remember whether I tied up the wires with a cable tie when I stripped the rad, or if they were unused and just like that from Lotus. I freed them now in case I need to connect them as it will be easier to hide them again if they aren't used than to retrieve them after the radiator is fitted if I find they are needed. I don't know what the hose is; I cant find it in the parts diagrams- but they don't show everything. I had thought it might go to the headlamp motor but checking my pics from when I last tried to fix those, there is no sign of the hose attaching to it. Anyway I don't have one the other side. The hose disappears into the void above the wheel arch, heading for the passenger side of the dashboard, but I would need to remove trim to see where it emerges inside the car. It doesn't seem to be being used so I will leave it for the moment. (see blog "Heater" for more explanation)

Hose emerging from headlight pods via a brass valve-like structure. All firmly  clipped to the front of the nose.

I held the top section of the rad box with the front 3 bolts and then fitted the under tray. As you may recall  the captive nut for the RHS of the radiator undertray gave me a lot of trouble during disassembly and eventually pulled out leaving a larger round hole. I could have compensated for this by simply fitting a large repair washer and a nut and bolt through from the headlamp pod (as indeed the upper tray is fixed) but this would mean removing the headlamp everytime I needed to remove the undertray to hold the bolt head for unscrewing- and this need turned out to be quite frequent as I replaced the radiator and needed to do a fair bit of test fitting. I decided to replace the captive nut and so secured an aluminum  M6 Rivnut in a large galvanised steel mudguard washer, this should keep rusting to a minimum.

Rivnut installed in galvanised washer

Flat file to allow the washer to sit alongside the crash panles with the rivnut in position

Finally I drilled and pop rivetted the washer into position.

New rivnut pop-riveted into position in front of the upper box mounting and next to the new crash panel. RHS is towards the motor (ie rear), radiator box top section held on by the nut and bolt to the left. The tray can then be attached to the rivnut using an M6 bolt.

The repaired under-tray fitted well and I installed two self-tapping screws at the front to replace those that were missing when I stripped.

I then tried to fit the rad...  It seems just about impossible to fit this from the front of the radiator box (i.e. from inside the engine compartment). However its a doddle from underneath. This means I had to remove the undertray again and the radiator can then just slide up into place. In my case I needed to fit the mounting brackets to the rad so to get these in the right position I fixed them to the top of the glass fibre radiator top box using their bolts to hold them firmly in place.

Offering the radiator up to but in front of the top clips already fixed to radiator box in order to mark the pop rivet holes.

I could then offer up the radiator from below (the car is already raised in my case) and fit it into the clips. Of course the clips would usually fit inside the channels at the top and bottom of the rad but by overlapping the rad outside I was able to mark through the holes in the rad channel side to indicate where my new brackets needed to be drilled.

Brackets removed from car and installed into radiator matching the marks with the holes in the radiator top channel..

Drill holes for...

... pop rivets

I could then remove both the radiator and brackets, fit the brackets in their intended position in the radiator top channel and align the marks with the holes in the radiator side. I could then drill through with a 5mm bit and pop rivet the brackets into position for a perfect fit. These 5mm rivets were a real pain as they tended to jam in the gun and the force needed to compress them was quite high. I would prefer to use 3.5mm rivets, but I think the 5mm are really needed for the rad which will be quite heavy when full. As time went on I found the secret is to make sure that both the nozzle and the rivet guide are tightened up into the gun with a spanner- hand tight just isn't good enough and seems to favour jammed rivet tails.

The next step is to fit the radiator using the now permanent top brackets and retain it with their nuts so it hangs from the top of the rad box. Fit the other two brackets to the rad under tray and offer the tray up to the radiator to repeat the marking out process. This worked but you do need several hands and very long arms- again much easier with two!

Marking out positions for pop rivet holes: Radiator is secured at the top via the newly installed brackets and the bottom brackets are fitted to the under tray which is held in position using your third hand for marking. 

As I have already ordered new hoses- or thoroughly cleaned those that are still serviceable (most needed de-rust treatment as there were  crunchy rust deposits inside); this just about completes my cooling system overhaul. The only bit I haven't dealt with yet is the heater see on!