EdWills

This site (below) may be the same source as the assembly manual alluded to by 'Croc'. Apologies if this is duplication on my part. W.

Someone going by the name of 'Barnblinker' http://barnblinker.com has very kindly taken the time to download the entire Lotus Seven Series IV parts and service manual on to his site. The Lotus Seven parts manual by Caterham covers the Series 2, Series 3, and Series 4, if you can find a copy. Will

Redline Components U.K. has the chassis mounted rubber bush part number 046D 6000 in stock for just over 43.00 Pounds Sterling (each), if this is the part that MV8 was referring to above? This is/was possibly a front or rear bumper mounting rubber used on a different make and model of car, or possibly on another Lotus as an engine mounting rubber insulator. Will

A good source of information regarding the Lotus Seven Series IV is a gent in Germany by the name of Hajo Steffen. He has produced a couple of Youtube videos, and runs the German Series 4/IV club. I do not have his current contact details, but he can be contacted via Youtube or Facebook? He can advise on parts availability as well as history on the Series IV as necessary. Will

Hi Chris. Please see the post to your other entry on this forum. Will

Hi Chris. Dennis Ortenburger in his book 'Legend of the Lotus Seven' on pages 106 and 107 provides information on the Super 907 twin cam, and the deal between Lotus and Steel Brothers, heavy equipment manufacturers in Christchurch, New Zealand. I would try and copy the information to add here, but the book is new and doesn't fit very well in my printer. Steel Brothers only manufactured the cars until 1979 according to Ortenburger, as new safety regulations came in force in New Zealand at that time, and the 907 could not meet the standards. I contacted Steelbro in 2002, and a Mr. Alistair Coleman of Steelbro confirmed that his company sold the jigs, but understood that they had been sold on again to Club Lotus New Zealand, based in Auckland. He provided a contact phone number for Warwick Chandler in Auckland. Murray Osbourn of Club Lotus confirmed that they were attempting to keep the Series 4 going by providing parts and chassis for owners of the Series IV.. We are talking here about the early 2000s, so I do not know if this still holds true. As Steelbro were manufacturing the 'original' Series IV alongside Arch and Griston Engineering, parts should be interchangeable, except probably for the 907, as the chassis was stiffened to the tune of 20 lbs. of extra metal tubing, and widened. If the rear suspension links that you are wanting to repair weren't altered from the original IV jigs, Arch should still have the capability to either repair or fabricate new ones (preferably with bushes in place?). I have a very brief story of the Series 4 or IV if preferred, at anglocanadianlotus7.ca provided by the mechanic who worked on the Lotus production line. Tony Weale in his book also provides excellent details on the Series IV. hope this helps. Will.

Hi JB. My 1969 Lotus Seven Series 3, purchased from a great gent in Edmonton (I'm the third owner), had the 116E gearbox with close ratio gears and the pre-uprated 1600 c.c. Crossflow engine - 681F and 2737E block connected by a 105E bell housing and 7 1/2 inch clutch. The car had been fully built at Lotus and exported to the concessionaires just outside of Toronto (a number of fully completed Series 3 Sevens entered Canada this way, and as you probably know, a number arrived in Edmonton at Anglo Canadian Motors).. My car is L.H.D. The 116E was also fitted to the pre-crossflow Mk1 Cortina and the Lotus Cortina according to Paul Davies in his book on four cylinder Fords.. The early 105E and 109E boxes fitted in Ford vehicles only had synchromesh on the top 3 gears. After 1967, all boxes came with synchro on all 4 gears. My gearbox had the rubber mount that you show at the top in the first photo. It seems that the gearbox output shaft housing was available in 2 types to take either of the insulating rubber mounts as shown in the additional great photos from other forum contributors. The gearbox mounting cradle, as you and others note, was riveted in the tunnel. The hole for the rubber insulator mount in my cradle had become very large (the car was actively auto slalomed and raced by the second owner). Unfortunately, he didn't always check the tightness of all the major engine and suspension bolts! I purchased a new bracket from Caterham in 1970, and they had drilled a slotted hole to allow for side-to-side adjustment of the gearbox. When supplies of the 116E ran out, Lotus started using the 2821E box (incorrectly known as the 2000E). Near the end of the run of Series 3 cars (1970), the 2821E may have been substituted for the 116E. I have a complete build story from Cars and Car Conversions (July and August 1969), where one of the magazine's staff built a Series 3 for the magazine. It was fitted with the 2821E box. The Series 4 (1970 onwards) likewise was fitted with the 2821E, and when used with the twin-cam engine, the twink clutch at 8 inches diameter., and the twink bell housing, a special metal adapter had to be added extending the clutch release bearing to allow the clutch to operate correctly. Tony Weale details the part number in his book. The later rubber insulator as you show below your original, was used for the 2821E and the 116E according to diagrams in the Autopress Ltd., Ford Cortina 1967-68 Autobook by Philip H. Smith (U.K.), depending on the output shaft housing used. Caterham/Arch produced the reinforced metal bracket with triangular sides to fit in the tunnel area which was welded to the chassis. It incorporated a welded bottom rectangular tube to allow the rubber mount to be bolted to. Weale advises that the 116E was used on the Seven from 1962 to 1971, and the 2821E from 1966 to 1970. He does indicate that the latter box was used by Caterham up to 1980. Cheers, Will

Previous posters have requested information regarding Mick Beveridge of Xtra Special Sevens. I have personally purchased a number of items for my Seven from Mick, and in our last correspondence some time ago, Mick told me that he had not been very well. He is a great guy, a Seven specialist, and an excellent fabricator. Knowing that Tony Ingram of Fast7s has imported some of Mick's parts, I contacted Tony. He advised that 'I know that Mick had lost his workshops and that stopped him from doing any business'. Tony added that there was no contact from Mick anymore... I tried the only telephone number I have for Mick, and got an answering machine from another company now using Mick's number. As I, and others have found, there is no reply from the email address that Mick was using. A month ago I emailed him - just to find out if he was o.k. - but no reply. I sincerely hope that he is o.k., and it is a sad day for him and us if he had to fold up the company. Cheers W.

Hi Scott. Thank you for the picture. The poor(er)? relative of the Series 2 and 3 seems to have been left out of the plastic model kit world except for the model I have. I was pleasantly surprised when I found it. I was on holiday visiting relatives over the pond and took time to visit Brands Hatch racing circuit with my wife. I got to see one of the (four?) versions of 'Black Brick' in a club race. Owned by Rob Cox Allison, a very friendly/very likeable race car driver, who was perfectly happy to tell me all about his car as he worked on it in the outfield paddock area . Also racing was a standard Series 3 Seven owned and raced by Maynard Soares who won his class (rag top fitted, and when racing, looked like an inflated balloon). I would have liked to see the Lotus 7X racing. I was living in the U.K. at the time that Tim Goss was so successful with the car, but unfortunately had other commitments. I had attended Brands Hatch on Boxing Day a year before, and nearly froze to death. How they raced in such frigid conditions I will never know. Also very icy under some of the bridges. Cheers. Will

Apologies. This was sent off before I could load photos. EW

For Sale: 1/20 scale plastic model kit by Nichimo, Japan, of a Lotus Super Seven Series 4. It is mostly assembled, but the roll bar has not been attached in case of breakage. There is no damage on the model. A spare formed black metal wire roll bar is also included. There are not many separate parts to this model, so it came mostly assembled. To split the body from the chassis requires gentle prying at the bottom of the nose cone to release 2 small plastic clips. It can then be repainted if necessary to a colour of your choice. The headlamps, exhaust and windscreen can be removed if necessary for painting or masked off. The model is motorized, and requires 2 'AA' batteries, (but not included as the weight of these drives up the postage cost into the next price bracket!). The model was purchased in 1983 from a stall at Brands Hatch U.K., and sat on a shelf since then. The front wheels of the model have steering capability. I have found a couple of unmade boxed kits on line on e---, but they are very expensive as the kit has not been produced for a long time.. Offers in the region of $75.00 plus postage (tracked and insured).

Hi Terry. A number of years ago I required new brake piston seals for my 1969 Lotus Seven which is equipped with the later 14LF callipers from the Mk3 and 4 Spitfire (This information is according to Goodridge U.K.) Girling U.K. has a web site contact option, and may be best to contact as they can go back into their library and advise which seal kit is best for your situation. Goodridge U.K. were also very helpful, and supplied me with a photocopy of all the parts for my callipers. They mostly sell brake hose kits for many U.K. and European cars and did include the Seven, but I couldn't find the Seven kit on their site anymore. Burton U.K. were also very helpful with brake line kits and I obtained a 'vintage looking' set for my Seven from them. You probably know this already, but it is best that you do not attempt to split the calliper bodies undoing the bolts. A new small rubber seal would be required (this can be obtained still as a spare part), but leaks may ensue if the halves are not bolted back together with the correct torque. Lotus and Girling recommended that you should never separate the halves. Good luck with your search and kit experience. EW

I should clarify my statement regarding Haynes's valve size specifications for the Ford Escort Mexico in their manual. They are correct depending on the date of manufacture of the cars they were featuring. According to David Vizard in his handbook "Tuning Escorts and Capris", for Crossflow engines fitted up to August 1970, the valve sizes for the standard 1100 and 1300 were 1.41" diameter for the inlet, and 1.25" for the exhaust. The 1300 GT engine had inlets of 1.5", and 1.25" for the exhaust. The 1600 and 1600 GT engine had the same size valves as the 1300 GT. After August 1970, Ford started using the uprated engine, and the valve sizes increased to 1.55" for the inlet and 1.34" for the exhaust on the 1600 and 1600 GT. This was when the flat head was used replacing the head with the slight recess and the bowl in piston with no valve cut-outs. The uprated head required the pistons to have valve reliefs machined in the tops of the pistons. David Vizard advised that the best head for modification was the 1100 c.c. flat head casting. It had much more metal for enlarging the ports, as well as allowing for larger valves. Way back, I purchased at auction a 711M oil pump engine originally from an oil company for $25.00, and the head was fitted with the flat head 1100 c.c. casting with small valves. On a trip over the pond, I took it to Oselli Engineering in Oxford, and they installed hardened valve seats on the exhaust for unleaded fuel, bronze valve guides, and valves of 1.6" inlet, and 1.34" exhaust. They called this stage 2+. Note: 1.6 m.m. is considered the minimum space between valve edges to prevent cracking of the metal between the valves under hard driving including racing conditions. In my case, I have a space of 1.725 m.m. between the inlet and exhaust valves on my cylinder head. (There is a formula for this if interested?) Cheers, Bill

Hey Scott. According to the sales blurb for the 1970 introduced Ford Escort Mexico, the engine was a more economical power plant than the one used for the London to Mexico Rally.. The Haynes Manual for the Ford Escort RS1600 and the Mexico 1600, notes that the valve sizes for the Road Escort Mexico are the same size as the 1600 Crossflow pre-uprated engine used in the 1600 Cortina GT and Lotus Seven Series 3.. Seeing as the uprated 711M engine with slightly larger valves was introduced by Ford at this time (used in the Lotus Seven Series 4 and later Formula Fords), fitted with the flat head and stronger block with meatier mains caps, it is possible that Haynes were publishing older specifications for the pre-uprated engine in their Mexico specs. "A good example of a powerful but flexible use of a push-rod engine is given by the units used in the Works Escorts on the 1970 World Cup Rally. These engines were taken out to 1830 c.c. by boring and fitting a specially made long throw crankshaft. The flat cylinder head, with very little work done to it, retained standard valves but compression ratio was upped slightly to 9.5:1 by fitting Mahle pistons. Twin 45 DCOE Webers with 36 m.m. chokes were used and the camshaft was the Holbay R120 (my note: as used in the Lotus Holbay 7S Seven and available for the Series 4 as an extra). Power from this set up was approximately 140 bhp at little over the normal rpm figure. These engines were built with reliability in mind as much as power - and they proved successful, as everyone knows." Quote from "Tuning Four Cylinder Fords by Paul Davies" - published by Cars and Car Conversions Speed Sport Motobooks. So, I'm guessing that someone - perhaps other than Ford - has machined your head to take the maximum size of valves available. You may have to check that the area between the valves has sufficient metal as one tuning website notes that cracks can occur when the head is machined with the valve heads too close together. If I can find this site, I will pass it on to you if you are interested. Cheers, Bill

Hi Scott. In the article it shows the rear axle of James Whiting's car. No noticeable reinforcing plate to strengthen and prevent twisting to the axle and no special suspension set-up - just the regular rear 'A' frame. With the maximum 160 bhp on tap from the 1650 c.c. twin cam, and using the car for sprints and drag races, I guess the Ford axle can and did take the punishment without falling apart? James Whiting has another lightweight Series 2 Seven that he rebuilt with lots of alloy parts including gearbox, bell housing, and diff. carrier on it. Being an ex Rolls Royce mechanic, he has enough experience with cars to know what will and will not work. He has an extensive Seven restoration and repair business. I purchased a few sets of spark plugs with different heat ranges from him, and he was very helpful with advice. The magazine also featured Burton Performance in the U.K., who are excellent for Ford parts. Still going strong after many years in business with the same family in charge. Again, very knowledgable and v. helpful. Cheers Bill.

Hey Scott. Many thanks for posting this. I found the mag. at my Local Indigo/Chapters Store in Canada, and if anyone needs a copy they have a few left. $14.99 Canadian plus postage. Lots of interesting articles along with the Caterham 7 comparisons plus a description of 2 Lotus Mark 6 cars. Plenty of other great articles too. Cheers. Bill

Hi MV8. Correct, the thin lines are the coil overs. Len Terry was quite a character, and I had a few emails back and forth with him before he died. Regarding the layout shown in his book, he advised the following: "It comprises two simple frames, each forming a triangle with its 'upright', connected to a sliding joint. Each frame is located by a parallel-arm lower link, as shown, and by the usual top and bottom longitudinal radius arms which are not seen in this view. In the drawings the body is depicted purely diagrammatically to indicate the attachment points. This system keeps the wheels perpendicular to the road under any combination of bump, rebound and roll, and the lateral sliding travel at the central joint is less than half an inch. Unsprung weight is clearly rather higher than for a conventional rear suspension, but the advantage of no camber change could well outweigh this, and the structure does fit surprisingly well into the layout of a normal open-wheel racing car". Apparently, Len Terry did not incorporate this design into any of his cars, or those for Lotus (too bad!). Just an aside. Way back when Lotus was going up-market, they would sell off many of their sports and racing car spare parts at the factory. They would bundle them into wooden tea chests, 2 feet x 2 feet x 2 feet or so, and you purchased the tea chests more or less items unseen, not knowing what was in the middle and bottom of the container (you were not encouraged to dump the contents out at the factory apparently!). A friend of mine purchased one of the chests from the factory, and inside were a pair of new cast alloy rear uprights, drive shafts, brake parts, wishbones and lots of other assorted bits and pieces from their Formula Ford cars and other G.P. cars. The price, according to him, was quite reasonable, and he planned on using some of them on a couple of Lotus formula cars that he owned, as well as a Seven. Best, Bill.

Hi Scott. The Series 1 and Series IV Seven had the battery mounted in the boot. It would probably require a smaller capacity fuel tank to accommodate the battery as per the Series 1 unless you can mount a fuel tank above it as in the Series IV. In the photo above, it appears that the boot board is sitting much lower than normal for a Seven, so allowing the battery and fire extinguisher to be fitted there. With the de-Dion set-up on this particular car, there should not be a problem of the differential case hitting the underside of the lowered boot board (a definite possibility with a solid rear axle car) as in the de-Dion set-up, the diff case is bolted firmly in place. You can check SimpleSevens.org, and search the 'History' section, click on 'David Porter's 7/20' article, and at the very bottom of this section there are photographs of the bare chassis of a 7/20 look-alike race car. In one of the photos it shows the bracket for installing a battery at the rear on the opposite side from the driver. The fuel tank in the 7/20 is smaller than the regular Seven Series 2 or 3 tank. Caterham had a battery bracket manufactured by Arch for their Sevens that fitted on the passenger side of the car in front of the firewall in the lower engine bay area. Tony Weale noted that it may be difficult to service the battery in this location, and Caterham resorted to using a 'no maintenance battery'. If you check the Odyssey Battery web site, there are various sizes of dry cell batteries that may be suitable for your use. USA7s has a forum page detailing various batteries for the Seven with recommendations from owners. Cheers, Bill

Hello Gents. Although this design is perhaps not very practical for a Lotus Seven due to the cost and complexity of the system, this drawing of a De-Dion rear suspension by Len Terry would have complimented his other arrangement for the rear suspension of the Lotus Type Three Seven race car. The Terry design in the attached drawing is still in the Lotus vein with the small diameter tubular frames for the De-Dion suspension (as opposed to the large 3 inch? diameter tube used on cars such as the Lotus 11 and the Seven Series IV Clubman car). Note: Regarding the drawing, unfortunately, my copier doesn't work that well, and although I tried to eliminate light, it didn't work - my apologies. The 3rd picture should read 'FULL ROLL' and it looks like 5 degrees? I really like the look of this layout, and it would be an interesting project if time and money allowed. Cheers, Bill

Hi MV8 and Scott. Attached is Arthur Mallock's take on locating a solid rear axle in a sports car using a Watts linkage system and disc brakes. The very early Mallocks were fairly similar in appearance to a Lotus Seven. Arthur Mallock advised me that he worked on a number of Sevens in the U.K. for customers who raced their cars. As noted previously, this modification may not/would not be sanctioned by various U.K. motor racing bodies. Unfortunately, the extreme right hand side of the notes are cut off when being copied. This is due to U.K. paper size being different to that in North America. Mr. Mallock used long, almost parallel radius arms either side of the chassis to locate the axle fore and aft, but the attachment points are not shown in this diagram. Cheers B. .

One more image to add from Tony Weale's book on the Lotus Seven as requested. by MV8.. It shows the mounting of the spherical bearing mentioned in the post above. Happy New Year to all.

Hi MV8. These are the only diagrams that I could find. My thanks to David Kaplan for his series of bulletins, now posted on SimpleSevens.org (John D. thank you also), and to John C. and Scott (Iamscotticus) for their advice to post these. Image 1. This is the lower 'A' frame produced by DSK. It places the spherical bearing in the correct plane to prevent side-to-side movement of the axle without over stressing the bearing. When Caterham promoted the spherical bearing as a possible solution to premature failure of the rubber bushes, they placed the bearing in an upright plane (to fit their existing 'A' frame), and used bearing spacers and circlips either side of the bearing. I am not an engineer*, but I would think that this will place more stress on the bearing causing faster wear on the bearing ball and its housing, and I'm guessing that it was never designed to be used in this way? Len Terry on his Terrier racing car, located the spherical bearing in the same orientation as DSK. Image 2. This shows the tubular brace designed to connect the sides at the rear of the chassis, just behind the seats on a Series 2 or 3. As MV8 advised, it does not add any un-sprung weight, but does provide extra strength to the 'A' frame and the chassis in one go. It can be removed if required to return the chassis to as built. Longer bolts and perhaps washers or shims may be required to centre the 'A' frame. Note: The drawing should read 'mild steel' not 'mile steel'. Image 3. This is a diagram of the original Lotus Cortina method of locating the 'A' frame on the car. The swivel is located with rubber bushes, and provided with a grease nipple to lubricate the swivel. The diagram is from the Autopress Ltd. Ford Cortina 1967 - 68 Autobook Workshop Manual for the Ford Cortina 1300, 1500 and 1600cc including Lotus 1967 - 68 by Philip H. Smith. *Note: I am not a draughts-person or good at drawing, so please excuse the add-ons in image #2. Oh well! Cheers, Bill.

Apologies, drawing would not load

Part 2. My apologies if I have gone on too long on this subject, but I forgot about an article I found in one of the Lotus Seven Portfolio books I have. In a magazine article from a U.K. periodical included in the Portfolio book, probably around 1969 or so, the author was advising how to recognize a 'genuine' Seven and what to look out for in the way of repairs and possible frame structure problems. He noted that some* owners of Series 2 and 3 cars made a fix at the location where the 'A' bracket attaches to the chassis frame just to the rear of the seats. They fitted a 1 inch x 18 gauge round tube with threaded inserts (1/2 inch - 20 UNF) in each end, and bolted this between the 'A' bracket ends with the rubber Metalastik bushes fitted to the ends of the bracket. Longer 1/2-20 bolts grade 8 or better (AN?) would be required, plus shims or washers to centre the 'A' bracket in the frame. (I purchased a packet of various thickness shims some time ago from Dave Bean with 1 inch o.d. and 1/2 inch i.d. - very useful). The 18 gauge hollow tube secures the ends of the A bracket to the rear of the chassis, and also adds some strength to the area of the frame just behind the seat squabs. As mentioned above, in order to save costs on the Series 2 (and 3 with an almost identical chassis frame), the tube fitted behind the seats at the bottom of the chassis on the Series 1, was removed on the Series 2/3. By adding the round tube between the front of the A bracket locations, it adds some strength to this area almost triangulating the tubing behind the seat back again. For authenticity, if it is required to return the car back to factory trim, the tube can simply be unbolted as it is not a permanent structure. *Note: I have never seen a Series 2 or 3 Seven fitted with this modification or viewed any photos of it, but in the Lotus Seven book by Dennis Ortenburger, he shows a Series IV with this modification added to the rear suspension. I do not know how many 'some' are, but the author of the article seemed to have knowledge of it! Bill F.

It was very interesting reading this link regarding 'A' frames, and also the technical notes from David Kaplan (of DSK). It has been well documented that, quote: 'Colin Chapman realized that the price of the Series 1 chassis frame was becoming too expensive to buy in. If the design could be simplified, the cost would be reduced. The original drawing by Ian Jones for the Series 2 is first dated November 16, 1959 but the model wasn't listed until June 1960. The 'A'-frame was not a Chapman invention, but on the Seven it was employed in an economical and effective way'. (paraphrased from Jeremy Coulter - 'Lotus Seven - Collector's Guide'). In Len Terry's book, he advises that the 'A' bracket layout that he incorporated on his Terrier Mk.1 'was inspired by that of the G Type ERA though the latter in fact had de-Dion suspension'. The ERA had the 'A' frame on top of the De-Dion axle, and the trailing arms were on the bottom. Terry overcame this by inverting the linkage to lower the roll centre on his live axle car.. "The A-bracket was ball-jointed to the underside of the final-drive housing. This variation has since been copied for several other cars, perhaps the best known being the original Lotus Cortina and later models of the Lotus Seven'. Len Terry worked as a draughtsman for Lotus during 1958 and 1959, then again at the end of 1962 to 1965 as chief designer. Note: The Lotus Cortina location for the apex of the A-frame had a swivel with a grease nipple, and used a spacer tube and rubber bushes inside the swivel where it attached at the axle bracket. When I had to purchase a new chassis frame from Arch/Caterham to replace my badly damaged unit (mid to late 1970s), it came with a new 'A' frame. The original had been braze welded, but Arch completely fusion welded my new 'A' frame. They had also machined the slots to take circlips to secure a spherical bearing if required. I've mentioned in another post how Caterham tried a couple of ways to secure the apex of the frame to the axle (ball joint, sliding ball joint), but a letter from their technical director advised that perhaps Chapman had it right, as - especially for a road car - the rubber bushes provided the necessary flexibility, providing the best suspension with this layout. This assumed that the rubber bushes would not be contaminated with oil or grease, and were kept at the correct tightness. I am not sure if the Ford axle suffered as badly as the Standard Triumph unit, thus the axle strengthening plate may not be as necessary? Comments please from those with a Series 3, without the steel strengthening plate or other mods added to prevent the Escort axle from twisting. One poster inquired why the radius arms on the Series 2 (and my Lotus factory built Seven Series 3, shipped to Canada) had the bend in them. According to Tony Weale, 'the Lotus built Series 2 Seven radius arms are cranked at their trailing end to provide clearance for the handbrake linkage of the Standard axle, and these parts continued for the Lotus Seven Series 3 though the handbrake linkage had moved'. No doubt Lotus had many spares of these, so used them up on the Escort axle cars. Caterham manufactured straight radius arm as replacements. Lotus also used cranked radius arms on the Series IV where they connected to the rear of the chassis frame. As you may note, all of my information comes from the many excellent books on the Lotus Seven by various knowledgeable writers. I purchased these books when they first came out as my car had been modified somewhat by the second owner (I am the third), and I wanted to know what was correct and what was not. These same books are now ridiculously expensive as it seems that they have not been republished. I really appreciate the input of the many knowledgeable contributors to this forum as well as the extensive library of lotus@se7ens.net originally started by John Watson. John D. and I have noted discrepancies in some of the books, but former Lotus factory personnel have put things straight on some of the queries we had. Bill F