Loud tapping- not little end or valve gear! Traced to servo NR valve -fixed!

Ever since I have restored this motor there has been an obvious tapping whilst it runs. Being the type of person I am I immediately assumed the worst and imagined another major overhaul. However, it didn't seem to be engine speed related, the noise comes on starting and acceleration, vanishes on overrun- obviously the motor is still turning then so this at least  suggests its not motor-originated. My next suspicion was that it was the speedo cable (I've had these tap on bikes) or something rattling on the pedal box which I have also changed. However these were eliminated and poking the stethoscope around the rear of the dash I found that the noise was detectable on the master cylinder but loudest on servo body. Finally I identified it to my surprise as coming from the servo non return valve. On close inspection I could actually see through the nylon cover and see the valve opening and closing. Its a ball bearing and when it closes it makes a metallic "tap". Research shows this is by no means unusual and experience could have saved me a 30 min search.

I have a short video of this phenomenon... needed  a bit of editing so sorry for the enforced freeware logos. 

Since manifold vacuum is related to engine speed the NR valve is needed to preserve vacuum in the servo plenum chamber. You wouldn't want servo assistance to vanish with engine speed would you? Consequently the valve opens when manifold pressure is lower than pressure inside the servo and allows air to be sucked out of the servo into manifold producing the vacuum inside the servo to assist the brakes. If manifold vacuum falls the valve shuts preventing air from flowing  from the manifold into the servo and so preserving vacuum assistance.  In other words the valve allows air out of the servo but doesn't let it flow in the other direction.

The most likely cause of this tapping behaviour seemed to me to be an air leak making it hard to maintain servo vacuum- either in the servo, the NR valve itself, or possibly even the manifold. However, given the rapidity of this valve movement, I would expect the mother of all air leaks as the cause. In fact I can detect no hissing from servo, valve or heater actuators so for the time being I'm going to ignore leaks as a possible cause.

One odd possibility is that this constant valve cycling is caused by pressure pulses along the vacuum hose. Ideally you would want the servo valve to respond to average pressure in the intake manifold, but every time cylinder 4 descends on intake there will be a transitory increase in vacuum in the manifold above no 4 intake valve... in other words just where the vacuum hose connects.  I am aware that this effect was a complication in later cars that used a vacuum driven ignition advance system for the distributor, and a restrictor was needed to even out these pressure pulses- the simple metal elbow of my car being replaced in later versions by a right-angled plastic junction with a narrow bore.

Whilst a restrictor would probably solve this problem, there is no evidence that such an item was ever fitted to my car and yet valve cycling wasn't a problem. There must be another solution. Checking the parts lists showed that Lotus specified a 711mm hose between the rear manifold take-off and the servo for early cars like mine that have no restrictor. It was so long it had to have a separate P clip to hold it out of the way on the bulkhead. I don't think Lotus would specify such an inconvenient length (or a length at all) unless it were important.  Looking at my car it seems I have a shorter hose at 670mm

My vacuum hose... 67cms only

Can these 5 cms really make a difference? I cut an extension of 10 cm and fitted it with a plastic hose joiner.

So splice in an extra length-I started at 10cm

I didn't expect anything- and indeed on starting I did get the usual tap tap tap... but after a couple of seconds this vanished. This behaviour seems reproducible- some tapping whilst vacuum is established immediately after starting and then none!

I am truly amazed that such a simple cure could solve the problem! Anyway I tidied up the hose, fitting jubilee clips to all joins and trimming it down a little so it fitted better. Currently my hose is around 72cms long and at this length it slips easily through the bulkhead P clip without rubbing on the fuel pipe- and I still have no tapping!

Looking vertically down the bulkhead at the hose routed through the P clip(its the black vacuum hose below PVC fuel pipe)

Incidentally if you do need to change the non return valve the original Girling kits are now hard to find and expensive.  Unlike the originals,  new valves such as those from Sjsportscars don't come with the sealing grommet.  You can manage with a normal grommet which will seal G10R270-12-210 although it's not shaped correctly internally. A better replacement can be obtained from Rimmer Bros where it's sold for the Mk1 Ford escort
https://rimmerbros.com/Item--i-BAU1019 .

Lotus Excel: Brochures, price lists and owners' handbooks.

I know its very sad but I like to collect the original sales brochures for any cars I own. They do appear on eBay from time to time so I guess I'm not the only one! Anyway I'm trying to assemble a set for the Excel...sadly Lotus didn't keep a library of their publicity publications, I guess running a cutting edge company in tricky times and a vicious market did tend to take priority! However, this means that as far as I can tell there is no definitive list of publications for any model. Some attempts have already been made and there is a rough chronology for most Lotus models on the Lotus drivers guide. However its not complete and having been compiled on the continent, it includes a few foreign language version which were not presumably available originally in the UK.  

Its possible to get wound up in an ever tightening spiral  if you collect this sort of stuff, so I will state here the limitations to my own collecting:  I limit myself to UK Lotus published original material although I do include road tests which I think were reprinted from the magazines at Lotus' request and used as publicity in showrooms. I don't personally collect  magazine ads or articles that weren't actually reprinted for Lotus. Anyway, my car is an '84, so I'm primarily interested in anything that covers the period when the Eclat became the Eclat Excel and finally the Excel. Beyond this my collection is more fragmentary but it does include something of the SE and SA models and currently it finishes in 1990. I hope to fill in the gaps later but unless (or until) I get a later model car this wont be a high priority.  

Lotus printed several types of publicity material.

• Model Brochures covering one or more models
• Price lists covering one or more models
• Dedicated  single model sheet fliers often combined with other items in a folder
• Range guides, range specifications and range price lists
• Colour range charts
• Press releases
• Special anniversary brochures and pamphlets

Not everything was produced every year- Its complex and I expect I have missed something!

Lotus have a nasty habit of not printing id numbers or dates on most of their (early) material so I don't know how many different versions may exist of any single item. Dates are obviously a bit of a guess and I'm taking them from the link above and guidance from the various style revisions to the car- and also to the brochure formats, Lotus badge and logo. As usual, if you can add any more info please get in touch and if you have jpgs of missing publications please let me know and I can at least make this page more complete- even if the gaps persist in my physical collection! 

1982

Lotus press release dated 1982. Announcement if the Eclat Exvel. I suspect this is incomplete and should be in a folder. Not currently in my collection.

1983: Single sheet Eclat Excel. tech specs on rear

 Gold covered Eclat Excel Brochure   2 sheet brochure opens to 4 pages, tech specs on rear

Silver cover Excel 6 pages 

A4 style Lotus price list Oct 1982

Reprinted from Motor Oct 2nd 1982 "Lotus Blossom"- Review of an early production Eclat Excel

1983

1983 The Lotus Excel  2 sheet brochure opens to 4 pages. Incorporates

Reverse of brochure above; note  the oval Lotus badging trade mark present on rear, lacking ACBC initials.

A4 style printed price list dated March 1983

Lotus colour range 1983 Note Silver metallic predates silver fox.

Reprinted from Autocar April 16th 1983 "Lotus Eclat Excel, paragon of poise"

1984

Lotus range brochure- black cover. This is the only black cover brochure I have found and I suspect it is in memory of Mr Chapman who had died in December 1982. I suspect that the 1983 brochures were at that time already in the pipeline if not actually already printed. Of course this may be wrong

!984 range brochure- inside. Further pictures/text on rear

April 1984 price list accompanying the range brochure. red cover.. This is an odd size (21 x 19.4 cms) and its the first time I have seen brochures and price list in this format. Until now and for many years price lists had been printed A4 sheets. 

Model specifications on rear

Single page info sheet for 1984 Excel

1984 "A new look for the 1984 Lotus Excel" Single sheet tech specs on rear. Surprisingly this sheet lacks lotus badges completely.

Range Brochure (4 sides)

 1984 model Excel

The above brochure describes my car which is also in silver metallic and I think its the last one that does.

"Locking horns" Road test comparison with Porsche 944 reprinted from Motor June 1984

Road test reprinted from Motor Oct 27th 1984 "Striving to Excel" Review of the new, updated Excel.

1985

In 1985  the range brochure appeared with green cover in A4 format. The Excel now boasts front fogs as standard. The Lotus logo has been redesigned, loosing the outer circle and Mr Chapman's initials

1985 The Lotus range for those with driving ambition; new style badge lacking initials

Oct 1985 range Price list - trifold brochure

Inside of price list trifold

Review reprinted from Motor October 1985 (not currently in my collection)

1986

1986 Range brochure - double folding sheet.

Excel 1986 brochure inside. Specifications on rear.

It gets quite confusing from here on in. 1986 also saw the launch of the SE and SA versions of the Excel. Separate brochures were produced for both of these.  According to the Lotus Drivers guide, there were two versions of the SE brochure but I haven't seen either.  If I ever acquire them I will add them to this listing.

SE brochure- 1986 4 pages (not currently in my collection).

 Interior of SE brochure.

1986 Range brochure 4 folding pages, cover has reverted to green

1986 Range brochure reverse

1986 Model range price list. This is the first list in the folded slim format (10.5 x 29.5 cm) and does not match the '86 range brochure above- perhaps there is another?. Mr Chapman's initials have reappeared on the logo

Range price list interior  Excel (all types)and Esprit

1987

UK sales fold out brochure Lotus Excel 4 pages folds to 8 sides. Dated 1987 it was actually released in Oct 86 with accompanying press statement.

1987 black cover range brochure.  internal pages below

Press release Lotus SE for 1987- released Oct 1986

Although this is an A4 sized dedicated model brochure, range brochures were still produced in the slim format with accompanying price lists.

1987 Lotus Range. Range brochure now in slim format

1987 Range back page specifications

October 1987 Range price list

1987 Range price list reverse

1987 also siwed this pull-out artucle frim Motor cimparing the Excel with a Porsche... evens but overall the Lotus came out well, let down by some aspects of build quality.

1988

1988 Lotus Range- slim format

1988 Range reverse

1988 colour range brochure Date uncertain

Interior

UK-Market-Foldout-Sales-Brochure-2-2-Standard-SE-SA

Reverse of brochure

Colin Chapman produced his first car (Lotus 1) in 1948. Thus, although Lotus (the company) wasn't founded until 1952, it was felt appropriate to celebrate 40 years of achievement in 1988/89. A celebration brochure "40 years of Excellence" made its appearance and was available in 1988 with associated press pack at the launch.
The brochure had sections on the history of Lotus as well as the current range and had a folder at the rear to accept individual model specification sheets, price ranges and colour schemes. The brochure was issued by individual dealers and had a space inside for a dealer's card. This means it may not routinely have included lists of other UK dealers although this was present in the press launch pack.1988 also saw the issue of a press pack, although I do not know how frequently these were issued. So far this is the only one I have come across and I suspect it is issued to launch the 40 year anniversary (not currently in my collection)

Lotus press pack (not in my collection)

Press pack contents

Press back brochure detail

1988 celebration press pack photographs

There was also a poster although I dont think this was issued in the kit

40 th anniversary poster (not currently in my collection)

1989

Cover- 40 Years of Excellence brochure containing individual sheets for models etc. I show only those for the Excel below- there were also similar sheets for the Esprit.

Individual flier sheet- lotus Excel

Excel- specs on rear

Individual flier sheet for the Excel SE

Excel SE specs to rear

Individual flier sheet Excel SA

Specifications for Excel SA on rear

1989 Colour range

Colour range illustrated on rear

1989 Price list

May 1989 Prices on rear

Special Edition- Aquascutum

This isn't so much a new version of the car but a collaboration with Aquascutum providing a different cloth for the seats and a set of luggage. I've never seen a car like this and this version doesn't appear in any of the range price lists. This means its pretty much impossible to date so I've put in it '89 by reference to the car's features- but this could well be out a few years. Again if you know better please let me know and I will be happy to incorporate your info.

 

 1990

 The only publication I have identified from 1990 to date is this price list. This is the type that would have been issued in a folder and it seems that Lotus persevered with the cover artwork of the celebration brochure but removed the "40 years" statement for later years.

.

1990 Price list Excel (Esprit to rear)

1991

This is a motor show press release from 1991 containing much of what would be available in Dealer showrooms that year.- presumably these were issued every year but this is the only one I have seen.

 More to be added if/when acquired.

Owners Handbooks

I'd like to compile a list of owners handbooks as supplied to new owners with their cars but this is proving quite difficult. 

Its a little too expensive to compile a collection of these handbooks, so I'm forced to see what can be assembled when they come up for sale- or from current owners- and in that light, If you have the original handbook for your car please get in touch Ideally I'd like a JPEG of the front page and the publication number as well as the year of your car and the model and I will include it below.

Currently I believe that the early cars had the following

1882-5

Eclat Excel handbook. Publication No A089T 0324Z

1985

Pre SE Handbook, new style of wallet.

Publication number D089T 0324Z. I have seen examples with the same publicn number but the cover front page of the later books (as illustrated below E089 0324Z) but so far only from Australia and I dont know if these were ever issued in the UK.

1987 SE was supplied with this handbook publication no E089T 0324Z printed in 1986. Covers both SE and SA models.

1988 handbook supplied with 1989 car below.  Publicn no FQ80T 0324Z

This is the 1991 published handbook,  believed to be the last version produced.  Publication no G089T0324z. This particular copy signed by Oliver Winterbottom and Mike Kimberley

Blue cover wallet for this brochure. I haven't seen enough to know if the blue was introduced for this final version or if it was used interchangeably with the green cover.