clutch 9 inch vs 11 inch
 

Have what I think is A 37 truck motor.

It has an 11 inch clutch, fitting a 39 toploader to it for a fenderless hiboy roadster .

Obviusly I do not need the truck clutch for such a light car, but if I leave it, are they are harder to push the pedal, or any other reason to fit a car 9 inch clutch ?

If it is no difference I will leave it as to save changing the flywheel.

Re: clutch 9 inch vs 11 inch
 

I have a 11 inch in my 47 pkp. and it is a little harder to hold say at a stop light then my 39 which has a 9 inch Is your flywheel drilled for a 9 inch SUNSHINE

Re: clutch 9 inch vs 11 inch
 

In city traffic your left leg will get tired pushing the clutch. I would redrill for a 10 inch? IMO

Re: clutch 9 inch vs 11 inch
 

I agree. After double clutching the 11 inch clutch on the tonner in stop and go city traffic for several years I changed to a 10 inch clutch. This thread might be helpful in making your decision: https://www.fordbarn.com/forum/showthread.php?t=97208

Re: clutch 9 inch vs 11 inch
 

Have Fort Wayne clutch build you a 9" clutch,you will not regret it.Phil

Re: clutch 9 inch vs 11 inch
 

Foot pressure on the clutch pedal is one issue, but vehicle acceleration is the one I'm most interested in. The smaller in diameter (and weight) the clutch assembly is the faster the rotating mass can accelerate.

Re: clutch 9 inch vs 11 inch
 

I Agree with trainguy . Plus your left leg will thank you!

Re: clutch 9 inch vs 11 inch
 

Fort Waynr makes a nice 9" and it's much lighter. Now if you had a 302 HP Mustang with a T-5. You'd also have a 9" clutch. However the one thing an 11" clutch and flyeheel will do is:: Burn rubber with the engine turned off.

Re: clutch 9 inch vs 11 inch
 

Haaa! Maybe even spin the spare tire!!

Re: clutch 9 inch vs 11 inch
 

I would rather have a clutch that you don't have to pull the pan to replace.

Re: clutch 9 inch vs 11 inch
 

Thanks all for info.

Think I will change flywheels and go 9 inch.

Truck flywheel is not drilled for both.

Re: clutch 9 inch vs 11 inch
 

Or have your current flywheel re-drilled. However, doing with a new flywheel could allow you to find a lighter one.

Re: clutch 9 inch vs 11 inch
 

I use 9in. in about 90% of my engines (Fort Wayne) If its a real hot engine I have them install stiffer springs the PP, the 9in. is a lot lighter than the 11-10 set up. NOW, this is for street rods mainly. Walt

Re: clutch 9 inch vs 11 inch
 

Walt what flywheels do you tend to use? Stock, turn-downed stock, aluminum with steel insert ?

Re: clutch 9 inch vs 11 inch
 

From someone who has an 11 inch in a fenderless truck use a 9 inch

Re: clutch 9 inch vs 11 inch
 

The aluminum wheel with the steel insert is nice for real light car 12#, but expensive, It's a lot cheaper to turn down a stock wheel to about 20# and have it balanced. If you use a real light wheel in a heavy car it's hard to take off up hill, you have to rev the engine. Remember a Model A engine has a 65# flywheel and 40HP, if the engine dies you can ride home on the flywheel. Walt

Re: clutch 9 inch vs 11 inch
 

Yep, I like the light flywheel/clutch assy in a light (stripped down) car. Just curious about your input.

Re: clutch 9 inch vs 11 inch
 

I have an 11" in my truck, came that way from Ford, I can't tell the difference between it and the one in my 06 Jeep. Neither causes any undue fatigue.

Re: clutch 9 inch vs 11 inch
 

Does the throw out bearing sit in the same place out from end of crankshaft on both the 9 inch and 11 inch ?

Ie, are the flywheels the same thickness and when clamped down, are the fingers in identical positions ?

Reason for asking is the sump is back on and I am wanting to mock up the engine/box /pedals/ tailshaft assembly, and will change the flywheel /clutch when pulled apart again.

Re: clutch 9 inch vs 11 inch
 

What Walt said X2.

Walt, I will bring you a couple extra lipped flywheels for 9" clutches when I come up to see you.