Hey there everybody, I have a question that I cannot seem to find an answer to. It isn't for me, but for my grandpa, who is my reason for getting into this hobby. He needs to replace the clutch on his 40 Ford, he is running flathead with the stock side load transmission behind it. He says he thought he remembered someone telling him that there was a chevrolet pressure plate that he could run in his transmission. He said that the ford pressure plate just has 3 "fingers" in the pressure plate versus the chevrolet pressure plate that has "fingers" all the way around. Hope this makes some kind of sense to somebody out there. If more details are needed I will call him and see what I can find out. Thanks for any help on this one.
I would stick with the Long style 3 finger cover and proper disk. The diaphragm uses a different bolt pattern cover, different disk and throwout bearing.
Why would a person want to put a inferior pressure plate in where a superior plate was? Tell your dad looks are deceiving and the inferior multi finger pressure plate will generally wear faster and apply far less clamping force than those supplied by Ford. LONG STYLE CLUTCHES <table border="0" width="78%"> <tbody> <tr> <td width="50%"></td> <td width="50%"></td> </tr> <tr> <td width="50%">Exploded view</td> <td width="50%">Counterweighted lever (top) and standard lever (bottom).</td> </tr> <tr> <td width="50%"></td> <td width="50%"></td> </tr> <tr> <td width="50%">Typical Long Style pressure plate</td> <td width="50%">Weights are added to the clutch levers to increase the plate pressure as RPM increases</td> </tr> </tbody> </table> Long style pressure plates are the Ford version of a three lever, coil spring pressure plate. The Long Style is the most popular type of pressure plate for drag racing applications. It's design is the basis for today’s professional drag racing clutches. The inherent advantage of Long Style pressure plates is their ability to apply centrifugal clamping pressure. As engine RPM increases, the levers in the plate pivot against the cover and apply additional clamp load to the clutch disc. This is true in both counterweighted lever Long Style pressure plates and also non-counterweighted designs. (Counterweighted levers have provision for installation of weights to the backside of the levers to further increase the centrifugal clamp effect.) The The Long Style pressure plate is best utilized with mechanical release linkages. Long Style clutches were prevalent in early Ford muscle cars and trucks. Some Long Style clutches feature adjustable static pressure. By turning an allen screw located on top of the spring, the pressure can be increased. The Ford pressure plate is a pretty tough unit. Tremendous clamping power and long wearing. "three fingers" and all. .
Alright, alright... So my technical terminology was a little off, but I'm glad you guys knew what I was trying to get at. Thanks for the info. I'm not sure why he was talking about making the swap, but from the sounds of it, he is better to just stick with what he has. I noticed the there was mention in that article about being able to adjust the pressure with some allen head bolts? I have never messed with one of these transmissions before, is that something he needs to keep up on like maintenance or is that just an option? He says he needs a new clutch and wants me and a buddy of mine to do it for him since he is going through chemotherapy right now. I am just trying to get my ducks in a row before we dive in. Thanks again for the help guys, I really appreciate it. He is where I get my love for these cars, so if I get a chance to impress him or at least keep up it's great.
We've had good luck with Fort Wayne Clutch.They've supplied us clutches and rebuilt pressure plates with heavier springs for a number of flathead builds. Knowledgeable staff, reasonable prices, fast turnaround.
What I think is the only direct swap for a "Chevy style" plate onto a flathead is not applicable to a pre-1949 flathead...this would be a '49-50 Mercury pressure plate on a '49-53 Merc flywheel, usable on any post 1949 flathead adapted to early Ford integral bell type trans. The flywheel needed is not compatible with early block.
I'm not tying to sway any decisions, but some facts may be helpful. 1-The diaphragm ("Chevy") pressure plate has two different finger styles, "straight" for large T/O bearings, and "bent" for smaller bearings. 2-Diaphragms, normally with 6 evenly spaced bolts, and direct replacement for Borg&Beck plates, (like '49-'53 Mercury, early G.M. etc) are now available to directly replace many Long (Ford) style pressure plates with the 3 pairs of odd spaced bolts. 3-Diaphragms have been the standard OE pressure plate for well over 30 years, because they are cheaper to make, (fewer parts, no coil springs to mess with and/or adjust), require less pedal effort, and, for most uses, superior. Sorry moefuzz, 'ole buddy, I'll have to dis-agree with you on this one. I don't know of any high HP Mustangs/Camaros/Vetts/Chargers etc that don't use a diaphragm. I'm running a diaphragm on the flathead in my '32, and on the 428CJ in my project '40. Both engines use aftermarket steel flywheels that are drilled for both Long and diaphragm patterns. Both of my diaphragms are "off the shelf" items bought at our local clutch re builder, South Bend Clutch, but should also be available at other quality re builders, like Fort Wayne Clutch, etc. Matching the bolt pattern, H/P, finger height and T/O bearing is all that's needed for an exchange.
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