Christopher smith

I was wondering about that also given the aerodynamic situation with 7s. I seem to recall a point where SCCA had to clamp down a bit with some clamshell adjustments giving less drag. I think it was raising the rear of the clamshells a bit but wonder what it did for top speed at that time. I think back in 1959-1960 when the first 7s started coming across the ocean that USA federal regulations did not allow cycle fenders and that is why the 7A had clamshells. Some of us liked the looks so much that most (all?) Series 2 and 3 maybe had clamshells worldwide.

Very interesting article. Thanks. Does anyone know the history/reasons why SCCA moved the 7 around in so many production classes? I recall the 7 America with the Sprite engine was in F production when I raced in that class in my Sunbeam Alpine late 1970s (and got passed in the corners of course). The Super 7 with the 1500 pre-clossflow Cosworth and 2x 40 DCOE arrangement was in D production back in the 1960s. For a while it was moved to BP and ran against older Corvettes, beating them on tight tracks like Marlboro, Md. The SCCA production classes were supposed to be based on relative performance with quite a few modifications allowed. Later I think it moved back to D and ran against some pretty fast TR4s. I kind of lost touch with SCCA but much more recently I see that 7s are in FP and run against some pretty fast MG Midgets. I think the 7s may still have the 1500, but I guess has some pretty substantial weights added so can run against those Midgets. Can anyone fill in the blanks for around 1990 to 2020 or so?

Interesting info-thanks for sharing. Sure wished I had taken better notice of handbrake mounting back in 1986 when completely disassembling my series 1 just after importing it. Years later after many modifications and upgrades, putting it all back together was a bit of a mystery, at least for the handbrake. We finally found a way but sure was tricky. Ditching the idea of a full length floor pan as in series 2, substituting other reinforcements, was a good idea as access for many operations up front is very tricky.

Still have my series one number 475. It has lots of series 2 and series 3 and racing updates but by the time I got it finished some years ago I figured I was too old for racing it seriously so converted it back for Street use and registered as an antique in Pennsylvania. If I could get my concentric slave cylinder clutch setup working reliably I'd be using it more.

almost everyone used gasoline to clean parts long ago back when it was cheap. Still no cheap solution and I started worrying about toxicity when lead was phased out and premium lead free needed an octane boost. Sure aromatics can boost octane but depending on the refining process might have some benzene rather than just the toluene, xylenes and ethylbenzene. Sorry for Organic chem 101 here.While benzene seems like a great octane booster, the strong possibility of leukemia later in life is a terrible trade. Not that leaded gas was trouble free of course so please be careful whatever you use and avoid respiratory and skin contact. Long term health is very well established on benzene but others are not as clear and maybe not worth risking. Chlorinated solvents for brake cleaning also mean toxicity risks.

With a pH of 9.3 ( 7.0 is neutral) simple green or any alkaline compound should not be used on aluminum. Also, never put aluminum in dish washers as they employ high pH compounds many times. I would think a carefully used petroleum solvent like naptha with a brush would clean well and safely if done outdoors and away from any fire source.

West Marine has various locations selling retail, lots of fiberglass, resins etc. to boat repair and other fiberglass specialists so might recommend one for you. Trickiest part might be color matching

The clutch disc was from Neil@105speed.com . Neil McCarty offered quite a bit of advice and what I thought was a good price for a part not available in USA. I think the 190 mm 1 inch 23 spline was a real oddball that might have been original to one of the milder Mk1 early rear drive escorts which Ford USA did not export to USA. But that is what I needed to mate up my Ford Pinto gearbox to a 1500 GT Cortina Mk1 motor ( similar to early Super 7) since I had 2 Cortina boxes that were beyond repair. I placed the order on a Thursday just before the new tariff was set to kick in at midnight . I left the shipping up to Neil since he exports a lot and hoped it would work. I assume he specializes in old Anglia/Prefect and similar stuff that came to the USA in small numbers or not at all. UPS showed up the following Wednesday so very quick and figure UPS had already set up to handle the tariff crap. Used Pay Pal to pay Neil.

My new clutch disc came as one of the first imports from UK right after the tariffs were put into effect. Lucky it was only priced at 40 UK pounds as UPS made me write a check for 50% of that FOB price. I do not expect they will come back with a partial refund but I was happy it came so quickly.

I ordered a new 190 mm 1 inch 23 spline clutch disc to hopefully mate my Ford Pinto gearbox to my Ford Cortina GT motor.It was from from a UK dealer ordered Thursday just before the tariff went into effect Friday AM our time. I was surprised it came so quickly. I guess UPS had already put in place a system. I had to write a check at my door for 50% of the stated price ( not including freight). So I guess I was one of the first to be hit with a tariff.

Forgot to mention the importance of a pedal stop.If properly adjusted, allowing just enough to release the clutch disc and then just a little more per the Tilton info.

You may want to take a look at the tilton website as they have a lot of info about concentric slave cylinder throw out bearings and the Gap that they recommend for their products which may not be the same as Mazda

I am not familiar with either but suspect if they are fairly recent, you may have a concentric slave cylinder/ throw out bearing combination.Apparently some Miata years have that and since it is adapted to a different engine, maybe you have some after market adapter that is just not adjusted right. If so , sounds like the slave cylinder which wraps around the transmission input shaft could have over extended before it pushed far enough on clutch pressure plate fingers to release the clutch disc ( to allow shifting). So that would certainly dump fluid like I did a couple of tries ago. So not sure what adjustment method suites the Mazda or after market set-up, but you may need to open it all up and somehow move the slave cylinder/T.O. bearing combination a bit closer to the engine. Does the Mazda bellhousing have any sort of side, top or bottom opening for you to look inside and see if the concentric slave cylinder may have popped out, that is, pushed too far toward the engine?

sure sounds like what I have been going through with my concentric slave cylinder T.O. bearing unit. Mine is a Ford Cortina GT 1500, essentially the Cosworth 1500 used in mid 1960s Lotus Super 7. However the 2 grearboxes I had were beyond repair so a Ford Pinto box was adapted. Sure seems critical to have the spacing between the T.O. bearing mount, fingers of the clutch cover just right apparently. Too much gap and you will pop the hydraulic cylinder out the front ( so no more pressure) which is what I suspect happened. Or if too little space I assume you will have the T.O bearing constantly pushing against the fingers and will wear the bearing if light touch or disengage the clutch with no pedal pressure if heavy touch ( way too tight spacing). I am still working on it after an initial success with a Saab 3 bolt cylinder which finally gave up and Saab T.O. but now an my 3rd try with the Tilton bearing. What motor/trans are you using?

I always used a wink mirror for racing. I had an old one I put on the front roll cage and seems to work great. Not sure how it would be with a top up ( if I had one).

I really enjoyed driving in the UK shifting with my left hand. For one thing people who use the roundabouts actually no who has the right of way and respect it. That is not what we encounter when we drive in New Jersey where nobody seems to know who has the right of way

Probably best to adapt driving experience in N. America instead of parts. You will get some funny looks of course. We had a 1949 MGTC with RHD, no problem driving but that was a long time ago and, granted, it was laid up waiting for parts most of the time. The 7 series 1 is a joy to drive with RHD, again, not driving that much. I think the RHD driving position has you almost as close to the left side as a driver in many of the monster SUVs you see wallowing around. Never tried it with a top up or in the rain of course, but a wink mirror on the front of the cage works for me.

I wonder if the 7 point idea originated from someone having a failure at the floor mounting points of a 5 or 6 point in some adapted application with a very thin floor pan and somebody figured an additional point would spread the load. Sure would not have wanted to be the person who hit something hard enough to pull out floor mounting points- so just guessing. No doubt that sort of thinking was behind the rear (and front) angle bracing on roll bars back in the 1960s when roll bar failures did actually happen and something really was necessary. Happened to a very early 7 at Watkins Glen and they kept the crumpled roll bar to show during tech inspections as an example of what not to bet your life on.

I may have been to that same event. Saw him at The Glen, Bridgehampton, Pocono maybe as well. Great fun back then. I think I recall that the first Cobras did have tire traction issues until they tried Goodyear stock car rubber. Penske was our local dealer out in West Philadelphia and we got scrubbed Indy Car tires from him for a Mustang. Talk about loads of traction! Crazy times.

I guess it depends on what car and what you are trying to do with it as it varies widely. A bit of oversteer seems like fun but is not necessarily the fastest way around for some of us. However, everyone should, at least one time, watch the sprint car guys on a dirt oval then tell us about oversteer. By the way, their preferred tires look like an exact copy of the old Dunlop R5s from Formula 1 1960s. For autocross the hot set-up was race slicks on the front and street radials on the back. But that was back in the 1960s and I assume not allowed now. For SCCA regionals in my very old F production Sunbeam Alpine, I enjoyed outqualifying some of the E production cars, but those pesky 7 Americas in F with the Sprite engines would always fly through the corners and the D Production 7s with the 1500 Cosworth were way ahead. Later, a 5 liter Mustang was a real handful running with the Corvettes ,Camaros etc. so we did not want any major oversteer. Track day had not been invented yet so we did the best we could.

The USA car manufacturers and other makers seem to have always favored understeer and designed for it in an effort to protect drivers who do not have the skill to deal with oversteer. Having driven all sorts of rental vehicles for business in various road conditions I always was extra careful and conservative particularly with front wheel drive vehicles. The exceptions for sure were in Britain in an early Toyota MR2 and also an early rear drive Escort. They were actually fun to drive on the twisty back roads. I guess the preference for the track is what makes you go faster rather than choosing to hit the wall with the front or the rear. I opted for just a bit of oversteer but that was long ago and not in a 7 so my opinion may not count for much.

The Tilton 0400 type that I think will help has a wider release bearing (54 mm) compared to the other one that I could not get to work properly. It has a 50 mm bearing and a very different shape. I was told by clutch people in the UK that I should have a curved T.O. bearing like the 0400 type to go with the flat fingers on the clutch cover. With the old 50 mm it hung up in the disengaged position. Tapping very gently on the side of the unit with a 1/2 inch wooden dowel was all it took to get the fingers to push it back to the fully engaged position. So I think the slave cylinder mounting may be off by a couple mm and it is cocking the slave piston and making it hang up in the full release position.

It turns out the Borg and Beck HE3329 has the curved fingers although the ones in the Pegasus catalog photo looked flat to me. I just sent a note to Borg and Beck to see if they have one that has flat fingers, so await their reply. Hoping to couple it with an 0400 type slave cylinder/release bearing that is curved at 54MM. My 190 mm 1 inch 23 spline disc looks fine on inspection by a clutch specialist firm just outside Philadelphia. it is 8 mm thick which is the normal new thickness if I understand correctly.

The Pegasus itme will be here Tuesday so hope it works