Clutch Size in TCS

[thehackmechanic]

Hey, folks, I have a '74 TCS that's been off the road since '79. I just got the machined block back from the shop and am starting the assembly process.

I have a question about the clutch. This is a five-speed car, 365 transaxle. I've counted the number of splines and I come up with 21 (to be clear, I'm counting grooves in the hole of the clutch disc). The diameter of the transaxle input shaft appears to be 7/8". But the diameter of the clutch disc (or what Americans call the clutch disc and the Lotus manual calls the "plate" -- the part that has the lining on it) is 8". Everything I've read seems to point toward the TCS cars having an 8.5" clutch disc.

Also, the part numbers are confusing. It's just going to be a road car; I don't need anything other than stock. The Helix catalog lists 60-2848 as the part number for the heavy part (what I'd call the plate and the manual calls the "cover"), and 70-2011 for the lighter part (what I'd call the "disc" but the manual calls the "plate"), but Burton Power lists the Helix part numbers as 60-2842 and 70-1340 respectively.

Can anyone weigh in on what the Helix part numbers should be for both clutch parts on a TCS 5-speed, and what the diameter of the disc (the light part) should be?

Thanks!

--Rob Siegel

[BDA]

I'm afraid I can't help you with the specifics but I would trust r.d. Or Dave Bean to sell you the correct one.

[Roger]

The parts manual lists only one number for TC and TCS. I guess they're the same size.

You can however fit an 8.5" driven plate to an Elan, so I'd imagine you could do the same to a Europa, so long as one exists with the right splines.

[surfguitar58]

Hi Rob: I have zilch to offer wrt clutch knowledge (sorry), but just wanted to say I'm happy to hear you finally got your engine back from the shop and we're all looking forward to updates with pictures! If you are the type who responds favorably to deadlines, I am trying to encourage a modest turnout of Europas at British Car Day at the Lars Anderson Museum in Brookline MA on June 24th. I think we may have 2 so far. Keep us posted. 
Tom

[thehackmechanic]

Hey, thanks Tom (and others). I think the odds of it being up and running in time for the event at Lars are near zero. This is going to be a very slow-and-steady resurrection. Sandwiched between eleven other cars and unrelated life projects, I imagine it'll be three months before I have the engine reassembled, probably another three before it and the transaxle are back in the car, and at least another four before I've done even a cursory sort-out of the cooling, fuel, braking, suspension, and electrical systems.

FYI although there was very little forward motion for nearly five years, I nearly made a writing career out of the dead Lotus. Below are the three online pieces I wrote for Hagerty:

https://www.hagerty.com/articles-videos/articles/2017/10/24/lotus-europa-part-1

https://www.hagerty.com/articles-videos/articles/2017/10/31/lotus-europa-part-2

https://www.hagerty.com/articles-videos/articles/2017/11/07/lotus-europa-pt-3

--Rob

[Certified Lotus]

Keep the faith Rob, it will all be worthwhile! Follow my build thread for my 72 Europa TC, it will provide some insights to the magical (meaning I can’t figure it out) aspects of this car.

I enjoyed reading your articles. Can’t wait to read the next chapter......

[Sherman Kaplan]

Hi:

I have 73 TCS that was last driven in 1980.  I'm pretty sure that the clutch that came with the car is the original.   It measures 8 inches.
Picture below.  I just ordered a new clutch kit from Dave Bean. 

I'm just sending my block off to the machine shop.

Regards,
Sherman
Windsor,CO

[BDA]

I didn't recognize your handle when I replied to your post above. We had a short email exchange several months ago where I encouraged you to get back to work and finish your Europa. I'm sure you get a huge amount of email so I wouldn't be surprised if you don't remember.

In any event, I'm glad you're back on it! Hopefully I'll be more help on your next question!

Good luck!

[4129R]

Now that the snow has melted in Norfolk, I ventured out and measured 5 clutch plates I had lying around.

They are all 8" in diameter, and all from TCS.

[thehackmechanic]

Thanks everyone.

--Rob