Christopher smith

Henry Looks great! I have a bare TR10 axle housing I will give you (? shipping cost?). It should be the same as yours was originally ( unless the previous owner swapped out for an Escort or Ital rear assembly) but with no reinforcements or Lotus weld on attachment points, so a bit of a task to adapt to your car but a decent welding shop could do it. My car has the original Austin A40 (Sprite/ Metropolitan type) since it is a Series 1, so the TR10, common in series 2, is of no use to me. By the way, if you tear down the engine, you should see if it has a "rope seal" or newer type rear seal before you order the gasket set and get hardened valve seats so you will not need lead in your fuel like I do. Bean Engineering can fix you up. You might also want to check the valve lift (easy to do) to get some idea on the cam spec. . To check compression you can cc the head and I have some great diagrams/template info if you want to further deshroud the valves. Do you intend to track the car or street? I am curious about the rear strut brace diameter. That front brace looks like a good idea.

Just a thought. If dry sump, I would guess it also has a higher lift/longer duration cam as well. So that might make for some unusual idle effects. i doubt a previous owner would go to the expense of dry sump just for street use so probably has high compression as well. I think competitive racers back in the 1970-1980 era were running as high as 13 or more to 1 so good to watch the plugs for signs of detonation unless you use race fuel( you may not hear it with all the other noise going on).

Sounds like we have the same engine that was early Cortina based but now with 2x40DCOE2s, worked head, 10.2 to 1 , Newman cam from UK. Running on Sunoco or VP 110 octane to get the lead and no alcohol (way more octane than I really need).I sent my distributor to a specialist for a complete redo, elimination of the vacuum advance and an advance curve suited to track. I eliminated the stock type condenser and have an external one I adapted to make it all work and reliable.Happy to discuss and send all details/documentation. I am in Philadelphia area.

I think it is because Ferraris started to look like Toyotas or was it the other way around? So who needs aerodynamics anyway? And yes, we stand out!

Thanks MV8. Maybe I should go with that carb set up but the dual side draft are a real Joy when the RPMs are up.

Sorry if my info on scoops was confusing to anyone. I chose aluminium to match the look since my bonnet is unpainted 3003-H14. For anyone contemplating a composit approach and may be less familiar with the technology, the term "hand layup" refers to the method real craftsmen use employing a carefully done mold (female in this case) and appropriate layers of gel coat, surface veil and then the layers of glass cloth or chopped strand mat unless you want carbon fiber or Kevlar. Such a product is far superior to SMC (sheet molding compound -think Corvette) or spray up as used on mass produced items. It has a superior stiffness to weight ratio and should be less prone to cracking as well. My opinions are based on 30 + years spending time in many shops and factories employing all these materials and methods. So I have seen a lot of fine work and cheaply produced manufacturing as well. I will admit my communications skills are lacking however, but I am trying to share some important info and very much agree with others who shared info previously and it is fortunate that scoops are now already available.

I needed about 10 mm more clearance for the top of my 2x40DCOEs on my old Cortina GT 1500 motor in my 7. Had a beautiful teardrop made in aluminium. Shocked at the cost- it was more than I originally paid for the car when I found it in the UK a long time ago. Hand layup fiberglass-polyester must be the way to go for scoops

Graham-yes- we were just discussing that. An extreme cleaning and then a small, thin mild steel plate bent as precisely as possible to fit over the crack and re-brazed ( not welded, as you correctly caution) might work. I recall from "Welding and heat treating"class in the engineering department at Penn State just how strong a lap joint can be if brazed properly. Without a plate it would essentially be a butt joint and might just fail again. That all assumes future use in low to medium stress conditions so no slicks or high torque applied.

Great info for any series 2 owner. I had not seen it before. I guess I should be very happy that my car has retained the series 1 suspension design, unaltered, in my series 1, 1959 # 475. It has the original A40 axle ( seems to be the same as AH Sprite Bugeye), modified by Lotus for attachment points according to my receipts from Lotus dated 1959. So it has no central diff pick-up point like series 2 and therefore no twisting of the housing as described for series 2. Not sure why they changed that when they went with the TR10 axle. The original design for lateral axle location has the right lower arm with a welded additional diagonal tube (making a wishbone) that connects from just inboard of the right brake area to a square vertical central tubing member and pivots just a few cm back behind your left hip bone (they were all right hand drive). Anyway, back when I was gathering parts such as the 1500 non-crossflow and dual 40DCOE set-up, I sort of recall the ex-racer saying he had no use for the bare TR10 housing but that I would certainly need it if mine broke. But of course it has been of no use on a series 1 so needs a new home.

Sure I can send it. Can you call me at 215-233-1666 to discuss

The 3003 H14 is what I used also. Hint: If you need to "form" it, like over the round rear tubes on my series 1, the trick is to take an oxy-acetylene torch, but run acetylene only and deposit black soot in the area to be formed. Then turn on the oxygen as well for a normal flame and very gently bring up the heat all over the area, just enough to burn off the soot but no more. That gives you the correct temperature to slightly soften H14 alloy so you can form it after it cools.

That concern about zinc reminded me that welders working on stainless and other chrome or nickel containing alloys (or plated tubes) may want to be sure of very good fume extraction/ventilation. Even grinding creates fine dust and, if oxidized, they may face some bad health even years later. Hexavalent chromium causes cancer and nickel allergy can be severe.

I guess it's just the guys who do flat out racing and I understand they've got enough power to get above 120 mph. Not sure what you do then. There was a rumor that some of the guys lifted the rear end of the clamshells up a little bit for better aerodynamics but got caught by the scrutineers

Thanks---Now I understand why I like that clamshell look. My older brother had a used1949 MG TC which I drove more than he did. That is, until a front spindle broke. He then got a 300SL but my experience with that was limited by very expensive issues with the special injection system. But at 16-18 years old you could not beat the driving experience. Stuck on sports cars ever since.

Just a thought----I agree that the GRP can have issues but also noted that the thickness of the wings is not enough to take severe loadings concentrated in a fastener area. They are made by hand lay up with fiberglass mat or spray-up process with polyester resin. This is not as strong as GRP parts made with multiple layers of glass cloth or better yet, carbon fiber. One solution would be to build up just a bit more thickness of a 40-50 mm diameter using additional mat or glass cloth and suitable resin (polyester or clear unfilled 2 part epoxy) easily available at a boat repair supply place or even an automotive supply. So if you have the wings off and upside down, it is an easy fix to make that area much stronger and less prone to failure in use.

Does anyone recall any definitve testing that compared lap times or top end? I like the looks of clamshells since that was required back in the 1960s and 1970s in the USA and it kind of stuck with me.

Any thoughts on reading plugs for normal or fast road use? For racing, we always used a full throttle run with a quick simultaneous shut of ignition and throttle and declutch, coasting to the pits. Does that still work with the much more modern engines? And is a light tan electrode color pretty good? We always used leaded race fuel so wonder if unleaded means a different color optimum. My experience is with the likes of 1500 non-crossflows and similar.

Yes- do watch words like "breakdown". But if you have any really old British car ( I have a 59 series 1 Lotus) also do not say "fire it up" or "take it for a spin".

Just a thought for anyone thinking about silicone hoses. They require a special clamp design. The old ones used before silicone can dig into the silicone. The proper clamps for silicone must have a smooth,flat surface clamping onto the silicone all the way around. As with so many polymer applications, there are correct choices and designs that prevent problems. In the past I have seen way too many misapplications where choosing the slightly more expensive plastic or rubber makes a huge difference in reliability.

One way to check valve guides is to get up some speed going up to the crest of a hill and then coast, throttle closed, in gear, down the other side of the hill. If you then accelerate strongly and a cloud of smoke erupts behind you it is probably guides or seals. The engine braking pulls a vacuum trying to suck oil in. If it smokes at other times as then possible rings are at fault.

I have enjoyed seeing the many opinions here about which tools and spare parts to carry along with questions and great advice on fixing all the issues that 7s seem to run into. I also noted that quite a lot has evolved, for instance weight. Starting at under 800 lb for series 1 (mine weighs more now), to around 800-900 for series 2 and then quite a jump to series 3 and I assume Caterhams are a somewhat over 1000. The early weight increases were probably not due to government regulations entirely but perhaps all the modern conveniences have added weight, and maybe some negative impact on reliability (as in more stuff to go wrong)? I doubt much has changed as far as comfort and I am more than fine with that. Noting that you probably can not beat a 7 for excitement, I was thinking about performance vs. reliability. Examples come to mind from other Lotus designs. Take the Europa and the Elan that many of you are familiar with. Now compare them with the Toyota MR2 and Mazda Miata respectively. Sure all those more modern safety features and size gain added weight and they are no doubt less fun to drive than the Lotus designs. But they did turn out to have really good reputations for reliability. I assume gains in safety like side impact resistance added weight (think about the central frame Elan) but I would bet reliability was engineered in without being responsible for much of the weight gain. Of course the Japanese were trying to appeal to a much broader market. Having previously owned, pit crewed or raced quite a few British cars (MG, Sprite, Jaguar, Triumph, Sunbeam, Formula V, Formula Ford etc.) I have seen some good and bad engineering. Stuff that gets stressed too far I expect to break or leak. I guess driving harder than the design limits may account for some of the issues. Has anyone had much driving experience in the models mentioned to confirm or dispute the fun vs. reliability aspects? Hope I am not opening a hornet nest.

Definitely not a series 4. Sure looks like a series 3 to me given the relatively wide rear wings (fenders). But any previous owner could have fitted the wider wings like I did to my series 1.

I stopped by the one in Washingtons Crossing , PA a while ago but not sure I can make it to WVa. I have not had the nerve to take my Lotus very far given its advanced age ( and mine). But I do hope to make the next NJMP event.

I was concerned about cracking the gelcoat also, so considered epoxy bonding slightly curved, wide fender washers to the fiberglass on the underside to stiffen the whole assembly, but decided I did not need it. I think it could be done without actually removing the clamshells. The carriage bolts look nice since they have no slots in the head but I did need to file a little of the fiberglass to fit them since they have a square cross section just under the head that keeps them from turning.

I used the stainless steel carriage bolts and stainless washers with rubber washers to protect the fiberglass. Deems to work ok but will admit I have not taken them to top speed so far.