Christopher smith

Anyone with experience with concentric slave cylinders? I have a 1500 pre-crossflow coupled with a Pinto box. There is a concentric slave cylinder to activate the clutch with rather intricate Aeroquip plumbing between the master cylinder, through the slave and off to an external bleeder. The slave gave out and leaked after years but not many miles, and I just installed a new cylinder and master cylinder. I replaced it with the same model (required engine removal, so quite a job). Now there must be a very small leak in the plumbing. Only a few drops leaking out somewhere inside the bellhousing, but I am getting a soft pedal even after extensive attempts at system bleeding to try to get air out. Can air be sucked into the system on clutch release through a very small improper joint in the intricate plumbing? I understand concentrics are used on a lot of race cars but I must have done something wrong. Ideas?

Great story! Us old guys have to stick together with crazy cars and stories. I love your current area. Mine is way too long, starting with my brother's MGTC and then his 300SL.

I have a fairly large sheet of 3003H14 0.040 and would be happy to snip a few small pieces and stick them in the mail for anyone wanting to practice.

I see there are quite a few videos about rust prevention materials and methods in cavities. Some of the wands seem to have wider tips at the ends so may not fit through rivet holes. I guess you could always drill more holes and put rivets in after treatment but the drilling cuts through any protective paint layer so that may be a concern. In any case those of us in the Northeast are very wary of winter driving with all the salt on the roads and even rain scares some of us for various reasons. Save that scuttle as they look very difficult to fabricate. I was lucky. The bonnet is not that bad to fabricate and floor pans and sides are easy. Rear wrap around is not too bad also. I used 3003 H14 for any parts needing a bend, but a harder alloy for a strong floor pan. For tight bends the trick is to apply a coat of carbon black using oxy-acetylene running very rich (no oxygen). Next you use a more typical flame, heating just enough to burn off the carbon and let it cool. That seems to soften the alloy just enough to allow easy forming in areas needing that.

MV8- Any details on that "boiled linseed oil" treatment? Boiled linseed was used in lots of solvent based paints ( the kind you can thin with paint thinner, generic term is Alkyd). That sounds like a great hydrophobic way to go to make sure water does not condense inside tubes with high humidity or rain and keep it from rusting the steel surface. But I think it would be too viscous to spray without special equipment. Maybe thinned with solvent like paint thinner? Very high pressure spray? I recall seeing adverts in various British car magazines for a treatment called Waxoyl. Any 7 guys used it here in the USA? Would WD40 be just as good sprayed in old, unused rivet holes with the wand?

Might be worth checking the bean engineering Ford racers catalog. It mentions two manifolds with photos and says one has long runners so not to be used in a seven.

Many thanks CarlB for that clarification on nitrobenzene. Although hydrazine (N2H4) has no oxygen on its own, I would bet if you adjusted the mixture it would go like "rocket fuel" and burn a few engine components while doing it!---in fact it was used a lot as rocket fuel but needed fuming nitric acid, liquid oxygen or high strength hydrogen peroxide to provide oxygen and work in rockets. And yes, hydrazine and the newer unsymetrical dimethyl hydrazine are really nasty. My work was mostly in solid rocket propellants ( Indian Head NOS) however.

For sure toluene is a great fuel and outstanding octane booster. I think the nitromethane was pre- WW2 Grand Prix stuff. I suspected that some of the early lead free pump fuels might have contained some highly toxic benzene which was not quite separated completely from the toluene processing. Probably ok now and since most of us have not gotten leukemia from the 1970s-1980s we are probably in the clear by now. Still best to avoid contact. Sorry for the boring chemistry.

Maybe those torpedo engines were running on Otto Fuel. It is mostly propylene glycol dinitrate which is essentially nitroglycerin minus 1 nitrate group. Terrible stuff to work with. Has anyone tried nitromethane in a seven? That is another example of a molecule that has its own oxygen and loads of energy. Crazy stuff for sure but I think Grand Prix cars used exotic mixtures decades ago in piston engines and drag racers still do.

Great photo. I went the Cuda route also. I bought new in 1969, a 340 4speed, LSD with a better ratio then got some shocks from a cancelled stock car order. A lot of fun autocrossing back then, embarrassing Corvettes, Mustangs, Camaros and a slew of British and German made entries at Marlboro race track. Glad no 7s showed up back then.

Way back in early 1960s my friend had a Valiant with a slant 6. We joked that it was a regular six that was so weak it fell over on its side. He later applied some hot rod tweaks and it actually became a pretty decent ride, at least in a straight line against some V8 powered overweight cars of that time. Sure could not shoe horn one into a regular 7 chassis. This new one looks like the way to go.

That is why I bought mine when I was in the UK for business + a side trip to look at 7s. That was 9 years after the advert shown. A series 2 in poor condition was not appealing, but a series 1 needing a motor/trans and a few other parts seemed like a good challenge.

That could account for the authentic engine sounds then. Thanks- glad the craftsmanship and money still exists to do that.

Thanks---I may have been fooled, but they sure sounded authentic unlike the small block chevy in a SWB 250 GT that ran around my neighborhood many years ago. Hard to beat that real 12 cylinder sound although I do love the small block at full song. That was along with 3 XK120&140 Jags. some of the neighbors converted. They had Ford, Pontiac and an old Chrysler Hemi with 6 2 barrel carbs and were actually lighter than he original 6 cylinder. I will stick with my 7 for sure. Anyway, it sure was a fun time at Goodwood when I was lucky enough to be close to their on a business trip. No 7s on the track that time however.

I have been 2x to the Goodwood Revival. It is September 8-10 this year with very limited ticketing. It is a super opportunity to see legendary race cars in actual racing mode. What surprised me is to see the variety of cars really thrashing about in side by side racing. Not sure I would want a 30+ million dollar 250GTO to be crashed into by a historic Corvette but the drivers do seem to go really fast on original type bias ply race tyres. You could get up close to most of the great cars and meet the drivers without a special pass except some of the really rare 1950s F1 , and TR250 and a few other really notable Can-Am types were in a restricted paddock area when I went back the second time. Also went to the Laguna Seca meet one time. That was also great.

you could consider the GT6 . Bolt on to my series1 so probably good for 2

We used to sell 1000s of tons of the stuff for all sorts of applications. Buying small quantities for home use gets tricky but I see Aircraft Spruce or suppliers for surfboard repair have some. You can hand stir it into almost any paint composition for brush on consistency. As a chemist, I would tend to go for 2 part epoxy liquids ( like West Systems)as a base and color coat with a spray can a few days after curing. Probably more trouble than most 7 guys would try.

We did some work with Dow Chemical research guys( formerly Rohm and Haas ) who wanted to formulate insulating paint for industrial use. Seemed like an insulating layer of low thermal conductivity made a big difference in preventing injury to workers in factories who brushed up against pipes of very hot chemicals or steam. If you touch a metal pipe surface that is hot it transfers heat to your skin very fast. Their coating prevented burns by allowing you that fraction of a second to pull away. The secret additive was very small particle size hollow glass microspheres in their acrylic resin paint formulas. Might just be a good lightweight solution for metal skins in the driver and passenger areas and very easy to add to virtually any paint formula. Disclosure- I retired a few years ago

I had really tough times trying to sort out pedal and master cylinder configurations and hand brake. I gave up on Lotus originality and went Tilton for pedals and cylinders ( with bias bar adjustment for front vs. rear). We finally sorted out how Lotus intended the hand brake as I had given up on the idea of serious racing and therefore got an antique designation for street use. I can send a couple photos if interested but my S1 is RHD with the hand brake lever above the passenger knee area but can still reach it with harness on.

I retired from several decades working for the worlds largest bead maker. Bead blasting was in a different group but I recall that glass bead blasting puts compressive stresses into metal part surfaces and improves reliability of many aircraft and race car parts. For thicker, highly stressed parts steel shot blasting is the way to go along with crack testing ( think connecting rods).

My 1959 Series 1 tunnel cover is rounded and very solid with lots of rivets so It seems structural to some degree. It may be that anyone later making a tunnel frame out of square tubing found it easy to cover it with thin gauge metal to keep hot air out of the driver area. Probably a good idea to incorporate a driveshaft retention into such structures in case something breaks.

I think I may have one of those trans mount assemblies unless I already gave it away. I got it from Caterham mid 1980s but had to opt for a Pinto box as my Cortina boxes were beyond repair. By the way, we fabricated a driveshaft retention loop just a bit aft of the tail shaft area in case something lets go. Obviously I am overly cautious and not all that critical on a little extra weight (My roll cage adds 80 pounds as it goes all the way to the floor tubes)

I have wondered for some time about S1 vs. S2 frame design. I think the photos last night clear that up. Thanks. I had read in a couple of places that Lotus decided that the S1 frame was more complex than necessary and started to remove tubes. Looks like the 3/4 inch round diagonals that triangulate the frame next to the S1 driver's ( and passenger's) upper and also lower leg areas were removed. Apparently Lotus thought the stressed inner skins in those areas compensated but I also heard that not everyone agreed--- something about rigidity? Perhaps they were looking at the very complex T61 "birdcage" Maserati being built at that time and decided to go the opposite direction.

I can send the "SCCA approved" Lotus drawing of the front frame area modifications. I assume some of our very racers in the USA found that cornering loads with wide slicks cracked the front frame members when way more than design loads were applied. They consist of 4 tube diagonals nicely placed as 3/4 inch round tubing. Pretty easy with the bare frame. I also added a couple more since my Series 1 was designed with a stressed member full floor pan all the way from the very back up and around the engine bay with appropriate cut outs below the diff and oil pan areas. I opted for a shorter floor pan similar to Series 2 (nothing in the engine bay) with higher strength aluminium for most but a 2024 stainless steel section across under the driver/passenger butt area. Highest strength aircraft "Cherry" rivets used throughout. By the way, Aircraft Spruce is a great place to find strong bolts and many other items and I would guess paint primer suited to aluminium.

Sure sounds like you are going through quite a decision process, much like mine years ago when I imported my 1959 Series 1 that already had fiberglass clamshells and nose but no rear wings, petrol tank, engine or trans. Otherwise pretty stock. Series 1 had Sprite type rears and those tiny drum brakes up front that I replaced with Triumph GT6 discs. My 1500 Cortina GT motor was a tight fit particularly because the previous owner in the UK had trashed the unusual 1300 Alfa twincam and trans but wanted to go Ford power and welded in a mounting structure. I just developed a leak in my concentric slave cylinder so this should be fun fixing. Good luck with your project.