11" clutch in a stock '40?

[Kube]

Guys, I'd appreciate opinions in regard to installing an 11" clutch in a stock '40. Pros? Cons?

[richard crow]

why are you pulling a trailer 10 inch works good. 11 hard on the left leg

[Ken/Alabama]

For stock I’m a fan of the 9” . Easy on the leg.

[Tim Ayers]

I know it's not stock Ford, but I absolutely love the Centerforce diaphragm clutch. As it breaks in, it is getting even easier to depress and it grabs and holds better than any clutch I've ever used. No shutter what so ever. None.

[bobH]

Kube, I'm surprised that you would ask. Too big, increased inertia, suitable for trucks, more leg effort, blah, blah. Rumbleseat wrote the reasons for choosing the 9-inch, and he was running a 'healthy' engine. I assume his notes are still available. If you really want an 11-inch, I'll offer to give you, stock flywheel, from 59ab, for 11-inch.
(And, has anyone here actually verified that an 11-inch pp actually fits into a stock 40 engine and trans. It probably does, but would be nice to know for sure.)

[deuce_roadster]

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A saying of a good friend of mine is "just because you can do something, doesn't mean you should". Are you working on a 134" wheelbase 40 truck??

[Bored&Stroked]

Originally Posted by Tim Ayers

I know it's not stock Ford, but I absolutely love the Centerforce diaphragm clutch. As it breaks in, it is getting even easier to depress and it grabs and holds better than any clutch I've ever used. No shutter what so ever. None.

Is this diaphragm clutch designed to use our big/wide throw-out bearings? Most of the ones I've looked at have an issue with the outer ID of the bearing hitting the "fingers" where it should not. The guys at RAM had never even pondered this until I brought it up and then they went and tested their diaphragm in a fixture and came back and said to me "we didn't think about that, but we don't recommend it". (Due to the interaction mentioned above).

Thanks!
Dale

[cas3]

I also have never heard of a "bolt on" diaphragm style pressure plate and throw out combination. Would be nice to know. I have a clutch issue to deal with this winter, my 59a with a merc crank, and merc cam will slip a 9" disk on a lightened ford flywheel. New parts from FT Wayne 5 years ago when they built in house. Rumble seat and late/great Bruce Lancaster both liked this combo, but I missed the fine print where they used stronger springs. Any way, mine has to come apart as its getting worse, I can't just baby it around forever !

[Mac VP]

The 11” clutch (Long style) will fit in the bell housing area okay. It’s just overkill to use it in a passenger car application. If the motor has been built up you might consider going with the common 10” but you’ll have to provide the matching flywheel. The original 40 flywheel had the big lip which would require machining that off, and redrilling it for the 10” bolt pattern. Or find a stock 42-48 flat flywheel that was drilled for the 10” clutch.

With all three sizes you have to pull the oil pan to change the flywheel. The bus/truck oil pan with the removable lower inspection cover would be a nice swap for the stock pan. I have two of those in our stash of pans…

[Tim Ayers]

Originally Posted by Bored&Stroked

Is this diaphragm clutch designed to use our big/wide throw-out bearings? Most of the ones I've looked at have an issue with the outer ID of the bearing hitting the "fingers" where it should not. The guys at RAM had never even pondered this until I brought it up and then they went and tested their diaphragm in a fixture and came back and said to me "we didn't think about that, but we don't recommend it". (Due to the interaction mentioned above).

Thanks!
Dale

Yes. It is a flathead specific part designed to be used with the old style throw out bearing. I highly recommend it.

[Tim Ayers]

Originally Posted by cas3

I also have never heard of a "bolt on" diaphragm style pressure plate and throw out combination. Would be nice to know. I have a clutch issue to deal with this winter, my 59a with a merc crank, and merc cam will slip a 9" disk on a lightened ford flywheel. New parts from FT Wayne 5 years ago when they built in house. Rumble seat and late/great Bruce Lancaster both liked this combo, but I missed the fine print where they used stronger springs. Any way, mine has to come apart as its getting worse, I can't just baby it around forever !

Centerforce does. I wish I took note of the part numbers, but I called them directly. The guy knew immediately what I was asking about.

[Bored&Stroked]

Thanks Tim - good to head that they have a diaphragm option that works. Does your PP have a Borq n' Beck style bolt pattern or a Long style bolt pattern? Would be great if it was a direct replacement for a 10" Long. Do you happen to have the part numbers (clutch PP and disc)?

[Tim Ayers]

Originally Posted by Bored&Stroked

Thanks Tim - good to head that they have a diaphragm option that works. Does your PP have a Borq n' Beck style bolt pattern or a Long style bolt pattern? Would be great if it was a direct replacement for a 10" Long. Do you happen to have the part numbers (clutch PP and disc)?

Dale, of all the things I took notes on, I sadly did not note the part numbers for the clutch set up.

When I called Centerforce, the Tech guy spit the part number out even before I finished saying, "Old Ford 3 speed", so it must be a common part they sell.

I did not get the dual friction clutch. The one I got is rated for 300 hp, so it should be plenty stout. LOL!

If it helps, the pressure plate bolted right up to the Weber aluminum flywheel. Not sure what style the Weber was drilled for. I'm starting to suffer from CRS disease.... Can't Remember Sh*t!

[sidevalve8ba]

Tim,
The only thing worse than CRS is CRAFT disease (Can't Remember A Frickin' Thing).

[Tim Ayers]

Originally Posted by sidevalve8ba

Tim,
The only thing worse than CRS is CRAFT disease (Can't Remember A Frickin' Thing).

Hahahaha

[Bored&Stroked]

Thanks Tim!

[Ol' Ron]

My favorite clutch is the 9 1/2 late one in the 49.later cars, but can't be used with the large input shaft (early transmissions). however when it comes to bucks ($$$$$$) and you have an 11" clutch, no problem, they have a nice smooth idle.
Gramps

[40larry]

yes. hard to hold down at stop lite. Once had clevis pin break and got big time scare.

[hotrodart]

I had an 11 inch/machined flywheel on my 296 inch motor with lots of specialty work (vintage dragster motor).....worked very well, smooth action.....but a bit tough on old legs.