vallianted
Well-Known Member
ok dumb question.is the difference between a 9.5 inch and 10.5 inch flywheel in the surface area or the actual total diameter of the flywheel?
Ted
Ted
flywheel
- Thread starter vallianted
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Yes. One inch.
vallianted
Well-Known Member
Tks I love this site.
There is a 10" clutch set with a scalloped pressure plate that allows the use of a 10" clutch disc on a 9.5" flywheel.......if a 10" will get you by. That would keep you from having to find a 10.5" flywheel if you don't have one. I have that set to use with my slant 6 when I make the Ford T5 swap. Of course that takes a disc with a different center hole, but they are available in the Mopar application as well.
NoCar340
The Original Partstitute
Both. Because of the larger diameter, you inherently have a larger swept area where the disc meets the flywheel. Assuming the same inside diameter between the 9.5" and 10.5" clutch lining, the 10.5" disc has an additional 15.7"² of swept area at the flywheel than the 9.5". Now, double that since the disc is two-sided. That's a big increase in friction surface, meaning much better clutch grip.
The only real downside, and it's not much of one, is that the larger disc has a greater flywheel effect on the input shaft of the transmission. That gets transmitted to the synchronizers, which don't brake as quickly. Hence, it's harder to shift quickly, if only marginally so. Unless you've driven both, you'll never notice the difference nor have a complaint. It's certainly not enough effect to forego the additional clutch grip. I've never had problems on any of my 10.5" cars.
The fly wheels are different Diameters and take a different bell housing.
cudamark
Well-Known Member
Both
Weber used to make an extra heavy duty 9.5 inch pressure plate. Used with the 273 hi-po disc it gripped very well - behind a 340 you could speed shift the 4-speed trans without the clutch slipping, but the pressure was so high it was a knee killer. Plus, I had to re-enforce the Z bar after one of the arms ripped where it was welded to the cross bar. Finally, after a couple of years, one of the release fingers would bend and then it wouldn't open properly. Happened to me twice. Then I bit the bullet and converted to a 340 bellhousing and clutch assembly. This was back around 1976.
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