racing/overdrive...?

[wangdango]

I have been racing a '56 Austin Healey 100 LeMans for yrs now, and just experienced a DNF (while leading the race, a Healey VS. Morgan Feature), it was a clutch failure. Took the car apart today, and the clutch cover inner disk was broken in 3 places. I do use the car's OD and wonder if the "shock" of engaging and disengaging led to the failure. We have the heavy duty spring and larger piston and this makes for a very positive engagement, but the "shock?" Does anyone suggest using the clutch when engaging? Just wondering what everyone thinks...

 

[dougie]

I use my clutch when dropping out of overdrive because it is usually during a down shift, but to set-up my entry to certain corners I'll down shift from 4th o/d to 3rd o/d then heal-toe and use the clutch to engage standard 3rd. That said, I think the failure of the inner disk of your pressure plate occurred over many years of vintage racing. My guess is that the disc developed micro cracks which finally spread all the way through the steel substrate causing it to finally fracture. I replaced my pressure plate a year ago during a motor rebuild when a wet mag test revealed it looked more like a road map. One more part your need to put the clock on.

Here's a vid of a little dice from last years Portland Historics between a pal in his '56 100-M and me in my 100-6 MM (which had broken rings in 2 cylinders-didn't know it at the time)
https://www.youtube.com/watch?v=cS6sqyTfNfs

BTY, I have a nearly new 12lb aluminum flywheel for a 100-4. If your interested send me a PM.


Dougie

 

[Michael Oritt]

Dougie--

Nice move on the last lap--I assume that is how you finished?
Great video.