vintage clutch questions

[John Fitzpatrick]

I need some advice here guys. My engine/ transaxle came out of a ’67 Formula 5000 car, and after reading some of the threads on this forum, I’m starting to get a bad feeling about my clutch. It’s a dual disk type, stamped “SHEFFIELD” and the disks measure 7 ½ inches in diameter. From what’s been said around here, I gather this is pretty much a race only clutch, but I haven’t been able to find anything on the manufacturer, so I don’t really know. The engine is a 289, ballpark 400HP, and the box is a ZF 5DS-25/0
My question is whether this clutch is likely to be streetable—not daily driver streetable, but at least “Drive through Dallas on the way to LA” streetable?
Second, if I end up changing it, is that going to require an engine tear-down and re-balance with the new clutch?
Thanks.

[Jac Mac]

John,

Your clutch plates appear to have a "marcel or wafer" between the linings on each disc so engagement for street use should be fine. There is no cushion in the disc hubs so a bit of 'snatch' in the driveline should be expected at low RPM unless your car has provision for it in some other area such as Metalastik Donuts in the halfshafts.

The Clutch cover [ With its 2 piece body ] looks very similar to that fitted to Rootes Group cars ( Hillman-Humber-Sunbeam-along with others ) around 1960/70.[[ Laycock???]]

Sorry, forgot the balance Q-If your can find a replacement that bolts directly to the original bolt pattern & it is a quality product then it 'should ' be OK. The thing is are you going to be able to find a suitable replacement from a drivability point of view. Tiltons, Quartermaster etc will be a lot harsher on engagement. Personally I would be quite happy with that setup once I had checked out that the clamp pressure & lining area were capable of handling the 400hp or more important the Maximum TORQUE that you have.

Jac Mac

[John Fitzpatrick]

Thanks, Jac Mac that's quite a relief to hear. The pads are 25-30 years old-- never used, but a bit dirty from handling it looks like. Any worriies over deterioration with age?

[Jac Mac]

The only concern would be if they have been wet & corroded between lining and wafer/marcel [ the rust/corrosion will literally 'blow' the lining apart aruond the rivets].
That does NOT appear to be the case from your photos.
To put the whole thing in context- If that clutch was able to transmit all the power of the F5000 thru its 15" wide slicks it should be able to handle your Lotus setup and I dont think you will be driving with the same amount of aggression as a 'red misted' F5000 competitor. Only thing is the F5000 car probably had more frequent maintenance than you are planning on!

Jac Mac

[John Fitzpatrick]

Thanks-the information is very much appreciated. About the maintenance -- we'll just have to see. as it does have Lucas electrics...
John