1940 flywheel

RAF

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Just pulled the transmission, clutch and flywheel from my 40 Ford and found this. The clutch and pressure plate are 9" but I am wondering if this the correct flywheel for the car. Never saw one with the deep dish like this one. Should I look for a flat flywheel or just have this one resurfaced and use it? I have not driven this car yet as I am still in the process of rebuilding it. Thanks
 

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Ken is correct in that is the authentic flywheel for your '40. Rotor is also correct in that some folks cut that lip off. I am one of them :) Be certain to have the flywheel balanced prior to reinstallation. Also, be certain the six tapped holes in the flywheel for your pressure plate are deep enough to allow the bolts to do their job.
Depending on how much is ground, and how much slag from grinding the shop leaves in each hole (clean them thoroughly) you may have to either shorten the bolts or, as I do, drill the six holes completely through and run the threads through as well.
Why Ford drilled and tapped bottomed holes in this case is well beyond my imagination.
 
Why Ford drilled and tapped bottomed holes in this case is well beyond my imagination.

Only reason I can think of was an attempt to keep someone from installing too long a bolt, similar to the distributer/timing gear problem?
 
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59 series will bolt right up but would likely have the pattern for the 10-inch clutch instead of the 9-inch.
 
I had my flywheel lip trimmed & balanced on my 59ab motor what a difference in power...especially gettin on the freeway!
 
But, you are saving wieght with the flywheel just to add wieght with a larger pressure plate and clutch! I would trim the original.
 
So how much weight difference is there between a 9" clutch and a 10" clutch? For convenience sake, I would go with the 10". The flywheel itself is much lighter than the 40 where the weight is concentrated at the outer edge.
 
So how much weight difference is there between a 9" clutch and a 10" clutch? For convenience sake, I would go with the 10". The flywheel itself is much lighter than the 40 where the weight is concentrated at the outer edge.

This is what I was getting at. Plus you may save some of the work and cost of having the '40 flywheel cut down. I like the 10 inch clutch idea too.

I have a 59A flywheel and a '40 flywheel. I could just weigh the flywheels and see. Although it may be a while before I can get that done.
 
Great question. If I weren't stuck here at work I'd get right on it. When I get time I will weigh a 59A flywheel, clutch and pressure plate. The 40 flywheel I have is still on the engine. Anyone else have one loose to weigh?
 
It's not the absolute weight, it is the weight at a distance from the centerline. A 10 inch setup is heavier, but not that much, it is the greater distance from the centerline. A 9 inch is going to be better for performance. If you are not that interested in performance then it is not going to matter. But if your not that interested in performance why be concerned about the flywheel weight in the first place?
 
I have a 59 flywheel that has been lightened. It weighs 26 #s. You have to overcome more inertia with a 10" clutch vs a 9".

How much can you so safely lighten a stock 59 flywheel. I have aluminum ones that weigh in at 12#s, , but I feel they are to light for a '40.
 
It's not the absolute weight, it is the weight at a distance from the centerline. A 10 inch setup is heavier, but not that much, it is the greater distance from the centerline. A 9 inch is going to be better for performance. If you are not that interested in performance then it is not going to matter. But if your not that interested in performance why be concerned about the flywheel weight in the first place?

Interesting information. So the answer is... go with the 9". Now, as a hypothetical, why not go ahead and engineer an even smaller (Dia.) set up like, 8" or even 6". Would that increase the performance even more than the 9"?
 
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