Technical Flathead Clutch and pressureplate, 11"

I bought bigger part used, old Ford Flathead parts. There was big clutch and pressure plate.
280mm = 11" OD and bolt circle is approx. 12.5". Where they have used these "huge" cluches?

AULIS

 

Usually in trucks. Hay haulers, dump trucks, etc. Sometimes in heavier cars (Merc) by the 50's . The ones I've got came with a heavy duty transmission with PTO cover on the side.

 

Thanks. Never seen clutch like that.

Aulis

 

i have 11" truck clutches in both my flathead cars. Mercs had 10" clutches. they are damn solid and dont slip although there is a weight penalty.. i think the pressure plate and clutch plate are about 6-8 lbs heavier than the 9" units. you can machine the flywheel more than this to get it bac down under 9" clutch weight. contrary to popular myth the pedal effort is no higher with the big clutch if the factory pedal/lever ratios are maintaned.

 

Using a 11" in my little pickup. But its important to not use the pressure plate. Your left leg will thank you. I rebuilt my pressure plate with weaker type springs.

 

The French and German motors were fitted with 11" clutches. At least any one I have seen had them. Makes sense, I suppose as they were all truck motors.

Mart.

 

I found an 11 in clutch in a 1948 f5 big truck used to haul firewood up and down the Colorado mountains.I have run 9 in clutches (lighter) in all my big inch FLATMOTORS and even in my first Anglia that ran high 14 's at over 90 mph with never a hint of slippage!

 

Just for what it's worth, I have had a pretty experienced machine shop refuse to cut any more 10 inch Merc flywheels down.....the have had one blow up in balancing and one blow in a car, seems where they take the meat out (pressure plate side) weakens old flywheels that are already stressed from years of pressure and use. They will chop other flywheels, but not the 10 inch Merc.