Thread: Pressure plate & flywheel

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Lightened flywheel, not a great thing for street driving ? Clutch staying on the floor @ 7200, needs heavier pressure plate return springs ? Any suggested resources for a clutch & pressure plate, would like to keep the parts matched ?

Cheers,

Are you not wanting to use a place like Summit or Jegs? No local auto parts stores close by?

I'm baffled as to the question..??..?? Are you saying the lightening process is overcoming the spring load in the pressure plate? Sorry for all the questions, I haven't heard this problem before, but I have seen folks lighten clutch components / flywheels.. I never believed it had much value myself.. I always thought the loss of inertia / momentum wasn't very valuable overall.

SO - I guess I asked as many questions as you! rofl....

Back in the day I had a diaphram pressure plate between a 331 SBC & rock crusher 4 speed. I had the same problem at the track, shifting over 7g, the clutch pedal would stay on the floor. Switched to a 3 finger pressure plate & the problem went away. Different geometry with the 3 finger.
BTW: I had an aluminum flywheel & Hilborn Stack injection on it. That little small bock was about as snappy as a 2 cycle, that is as long as I kept the injection tuned, which was a constant struggle.

As a side story I had a guy at the track tell me I didn't know how to shift. The next week back with the 3 finger clutch the guy said "I see you've been practicing" If he hadn't been bigger than me, I woulda' decked him.

Originally Posted by 34_40

Are you not wanting to use a place like Summit or Jegs? No local auto parts stores close by?

I'm baffled as to the question..??..?? Are you saying the lightening process is overcoming the spring load in the pressure plate? Sorry for all the questions, I haven't heard this problem before, but I have seen folks lighten clutch components / flywheels.. I never believed it had much value myself.. I always thought the loss of inertia / momentum wasn't very valuable overall.

SO - I guess I asked as many questions as you! rofl....

Two separate instances, the question about the fly wheel, was about the loss of inertia, that was not clear. I also believe that would affect the low speed drivability of the car and you seem to agree.

The clutch staying on the floor is different problem, the 3 finger design over the diaphragm, I had not thought about. 3 finger pressure plates are stouter.

How about places like Borg-Warner, Barnet these type manufactures, who's in the game these days and building good stuff.

Through the haze in my memory I remember one was borg & beck??? I guess bing/google will tell me if I'm right.

And then I found this. Maybe it'll help? What's the difference between Borg&Beck and Diaphragm pressure plates? - Corvette Forum

Diaphragm clutches can hang up if there's too much fork travel and they go over center. Adjust the clutch to the recommended clearance with the pedal on the floor, or install a pedal stop, and there shouldn't be a problem. I ran a highly modified 68 GTO 400/Muncie and a 30 Ford BBC/Toploader with diaphragm clutches and never had a problem. The GTO ran up to 7,000 rpm on the strip and never stuck. The Long style or Borg & Beck (both are 3-arm styles) may be a better system, but you have to have proper adjustment with it also.

If I were buying a clutch today, I would probably use a Borg & Beck style from a top-notch manufacturer.