Technical Who has a flathead Ford with an 11" clutch?

Though it's not powered by a flathead, I've got an 11" clutch in my '40. It's not that hard to push or hold down... and I'm an old guy.

 

I’ll be, I wouldn’t think 5 lbs would be noticeable, good info.

 

is there anything in a 1.5 ton truck want the spinning mass to pull it along
and more clutch to pull itself uphill laden?

or, in an ideal world do you want a lightened flywheel anyway in a little lightweight hotrod
with a modernerer multi fingered diafragm pressure plate and a 9.5'' clutch with with a radial fanned friction surface.

the cross shaft actuating arm on a truck is longer than a 35-40
is there anything in the pedal ratio?

that internet forum info.....
IF you 'need' a 24 tooth input or first motion shaft in that world class t5
that happens to want to be 9 1/4 inches long , and the v8 camaro is only 8 3/4 and too short, and the v8 mustang although 9 1/4 at 10 spline isn't available or you have theelong ford 10 plus one and need 9 1/4
you can get a 24 tooth input for the sierra cosworth or the tvr's that had v8's
they are 23 spline for clutch
however the 23 splined clutch is available in 9/5 240/1mm for the ford transit / cosworth tvr
10 inch and 11'' at 23 splines is land rover defender
moreover, there are millions of them out there and they are mighty cheaper

oh and if you are lucky enough to find a 8ba flywheel for 9.5'' clutch drilled 6 on 60 degrees, then the v6 camaro clutch is what you want, they are 9.5 and 26 splincant beleiv i had that all and now need it... bugger

 

I have an automatic in my 4 x 4 so it is easier to use the winch at the same . No clutch to worry about wearing out.

 

I think that this is the key to all of this.

 

I have 39 coupe with 11'' cluch, works fine and easy to use

 

I have a 1929 Ford coupe, 276 59A flathead running an 11 inch clutch. Because this is a lighter weight car the flywheel has been lightened and everything works just fine. When the new motor was installed and the 9 inch clutch was replaced with the 11 inch clutch, at first you could really notice the difference. The clutch was much stiffer. Now that the car has been driven to numerous shows and events and around town, the clutch feels natural and I wouldn't change anything.

 

Hey Joey, I put an 11" in the roadster because that is all I had. Home made linkage and it works fine. The 239 is stock. A smaller clutch will definitely spin up quicker but I'm happy
Good luck and have fun bro

 

11” in my roadster with the Scot blower (Ram diaphragm) and it’s pretty heavy. I have a 10” stock ford style in my sedan and it’s much lighter and holds just fine. You will spin these skinny hotrod tires before you tax the clutch I suspect!
Matt

 

Had a pickup with a 6 cylinder that had a 10” clutch. I switched to an 11” after going through 2 or 3 clutches in less than 30k miles. The flywheel already had the holes drilled and tapped for the larger clutch. Didn’t need to modify anything. It was a straightforward swap. I didn’t feel any difference in pedal pressure. The clutch outlasted the transmission.

 

One more thing to 'think-about'......with the slightly heavier 11" clutch you will NOT drop RPM between gears
as-much-as the lighter 9".
I don't have a dawg in this fight.......just stirring the pot !!
Personnal I would go with the light 9" AND get a lightened/Alum. flywheel to go with it. You ain't got a heavy vehicle to contend with......
6sally6

 

While I agree with 6sally6 on the 9", I dont think you need to spend money on the aluminum flywheel unless you have too much money, or are going racing. The early ford 9" flywheel with the blob cut off in a lathe is the traditional way to achieve a light clutch assembly that is all ford parts on a ford hot rod recommended by Bruce Lancaster, and rumble seat...nuff said

 

What is the measurement of a Borg and beck 8ba flywheel drilling for 9.5 or 240mm clutch pp, anyone have one for sale

 

What are the drillings on the multi drilled new fluwheels

 

Is there a difference between the distance from flywheel face to the three prong fingers of an early pp and the later multi finger pps

 

Diaphragm Clutches - Early Transmissions - There Can be Issues!

Something to think about if you're running your flathead with an early 32 - 48 style transmission: The big-wide throw-out bearing was designed for Ford Long style clutches (with the 3 fingers) - it was not designed for a diaphragm type clutch. I've seen folks use a diaphragm clutch with an early transmission and throw-out bearing - without thinking about where the contact point is when the clutch is fully depressed. In many cases it is NOT where it should be - on the "tips" diaphragm's fingers - it hits them way up on the fingers when fully depressed (due to the wide throw-out bearing face).

I discussed this with a very popular clutch manufacturer - who then took their "recommended" diaphragm clutch and an early throw-out bearing to a jig to test the actuation. They'd never thought about the issue and after actually testing with the early throw-out bearing, they no longer recommended using a diaphragm clutch in this common setup (32 - 48 transmission and throw-out bearing.)

 

i have a fresh (<5000km) 255 French Flat with 2x97 Navarro intake and heads plus a Literio L100, french factory relief, no porting (till now) plus a 39 3 Speed running the original french 11"clutch with F1 Pedals and crossmember in a 28 AV8 Roadster.
runs great and pulls to high revs without a problem. No issues with clutch pedal force or dosing.
but in the end i don't have a comparison to a smaller clutch.

 

Not sure how much is in your budget or what it's going into, but I have a Weber Aluminum flywheel and a Centerforce diaphragm 10.5" clutch and couldn't be happier. Clutch set up is rated at 400 hp and with the Weber flywheel, the car spools up very quickly. Great snap to it.

After break in, clutch feels like a small 9".

 

10.5" in mine as well - and I modified the linkage to give a little more leverage for the driver. The key is in the leverage - it can be as light as you wish if the linkage is done right. Start shifting the length of the arm or the pivot points and you'll find you can reduce your pedal pressure by 50% or more.

 

I used a Weber flywheel and (remember these?) Auburn pressure plate, 10". Auburn had a 'coverless' design, very lightweight. Used standard Ford T.O. brg., used to scare people standing nearby when I fired it up.
Super fast 'up and down', but the initial fast rev on startup... 'Wap! Wap'! Loved it!
Easy on the foot pressure, too. Used std. '39 lever on cross shaft, '39 pedals.
(In my red '32 5 window Hiboy)

 

What a timely thread, I was just thinking about this last night for an AV8 I'm about to barf together. I have multiple clutch options and vaguely remember the 11" being less desirable for a little hot rod.

 

Thanks for the info. I did the diaphragm PP in my 59A with stock throw out brg. ..... not driving yet. I'll be watching for this problem.

 

C'mon, Dale. Don't be coy. Who did you speak to?

 

I've got an 11" truck clutch in my '40 with a 331 Cad also. I don't think the clutch is too hard or stiff to drive, but when I get in my flatheads with a 10" clutch they are like butter.

 

No offense intended here but the real question is what flathead needs an 11" clutch.

I think that the ford big truck ran an 11" clutch. Think farm truck or fire engine.

 

Correct ^^^^. Most folks use an 11" because thats what they have in stock. However, its not what they were made for

 

Anyone removed a cover from ANY pressure plate and checked spring tension? A weak 11" can be 'softer' than a strong 10".
Simple test can also be performed with a mechanical bathroom scale...
I used to check a pressure plate (9, 10, 11") by setting it on my concrete garage floor and stepping on a round block centered on the 3 fingers. Its resistance to my teenage 140 lb. gross weight gave me an 'educated guess'.
I tested them frequently.

 

One thing I haven't seen mentioned yet. Can a 10 inch clutch be replaced without dropping the oil pan? I had a two piece oil pan so no problem no matter what clutch I used.
My engine came out of a 46 fire truck with 18K miles. It had an 11 inch clutch but the end play on the rear main was excessive even though the bearing itself was like new. Some suggested the 11 inch clutch to be the reason. Too much pressure. Never could find any truth to this but I opted for a 10 inch.