shaving/lightening 59A flywheel

3

36tbird

Well-known member
OK boys and girls, I did a search both here and the HAMB and could not find anything on the techniques of shaving the bell weight off of pre-49 flywheels. I took mine by a couple of machine shops today and all were perplexed on how to do it. Basically, the problems seem to be about how to chuck the flywheel up to cut the bell off of it. About the only place the machinists saw to chuck it up was the lip that the starter ring lives on. If you have to remove the ring, how do you do that and save the ring to be re-installed? Is it as simple as applying some heat to the ring to remove it and re-installing it? One gent suggested removing the starter ring, turning the wheel to cut off the bell leaving a short amount that would be removed when the entire surface is re-faced. I thought that this would be such a no-brainer procedure given it's long history in flathead hop up, but apparently it is another technique lost to posterity. Suggestions?
 
36tbird said:
OK boys and girls, I did a search both here and the HAMB and could not find anything on the techniques of shaving the bell weight off of pre-49 flywheels. I took mine by a couple of machine shops today and all were perplexed on how to do it. Basically, the problems seem to be about how to chuck the flywheel up to cut the bell off of it. About the only place the machinists saw to chuck it up was the lip that the starter ring lives on. If you have to remove the ring, how do you do that and save the ring to be re-installed? Is it as simple as applying some heat to the ring to remove it and re-installing it? One gent suggested removing the starter ring, turning the wheel to cut off the bell leaving a short amount that would be removed when the entire surface is re-faced. I thought that this would be such a no-brainer procedure given it's long history in flathead hop up, but apparently it is another technique lost to posterity. Suggestions?
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I think the way they did them was with vertical turret lath.If you can find and old shop that has one they could do it.They bolt it to a turning table and cut out direction.
 
I'm having a problem visualizing what you are saying. Why don't you get an old crankshaft and cut the rear main journal back. Use the flange to mount your flywheel and chuck the rear journal.
 
I did one on a brake lathe, in steps on different days... It takes a while!
If you want to remove a ring gear from a flywheel, use a hammer and punch, cold... To put it back on, heat about 1/4 to 1/3 with an accetelane torch. I hold it in a pair of vise grips, when hot enough it will drop on... If you need to, you can finnish getting in in place with the old hammer and punch... Karl
 
What, they don't have milling machines in TX? You better find a better machine shop.. It seems to me that its a lot easier and cheaper just to get a 41-48 flywheel doesn't need to be lightened.
 
I am not sure if this would work but couldn't a flange be made similar to the crank and that be chucked in the lathe? Bolt the flywheel to that the same as the crank and center it with the tail stock. I too was considering lightening a flywheel. It would take some prep work but it should work. prob. not the work that many want to fool with. Just a thought. Others on this board will most likely know. Van
 
I am surprised at how complicated you guys can make a simple 1 hour job.
You chuck it on the ring gear teeth in a 4 jaw with small pieces of aluminum
under the jaws, put a bull nose center in the center bore and have at it with a carbide tool...Once you have done a 100 or so you can do them down to 24 lb in an hour if you have 10 hp on the lathe.

Oh, by the way we don't "shave" flywheels, we MACHINE them.
Shaving is for whiskers or deck lids.
 
I had the local machinist do mine and I'm pretty sure he did it in a lathe. I think it was $60 for both sides. it weighed 34.6 lbs stock and weighs 24 or 25 now ( bathroom scales) If I remember correctly he cut the relief about 3/8" deep.
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Russ & V, I had the same idea as you. I mentioned it to one of the machinists and he presented that when you spin a large mass like that and go to cutting on it, it sets up a resonance/harmonics that could destabilize the whole thing. That made sense to me and that is why they want to chuck the thing up from out side.

Dick, I was under the impression that this had to be done on a lathe, but getting a mill to go after it sounds interesting. I will look at finding a shop that has that equipment. I did a cursory look for a new, already lightened flywheel, non-aluminum for a regular street driven car. Speedway had one but showed it was drilled for 10 1/2". I just want to use a 9" so that expense would include the flywheel, new pressure plate and clutch. Plus, a 10 1/2" may not clear the Offy adapter I'm using to bolt on a 4 speed top loader.

Pete, not everyone has the size lathe needed to chuck such a piece up. I grew up hearing the term, "shaved" flywheels. Maybe they were more "hairy" back then.:D

Thanks to all for the suggestions. Lou
 
I'm using a 9" clutch setup in my 32 and had the big ring cut off and a little off in some other areas to lighten it to 20-22 lbs. Of course, this is in a light car. If you are running anything bigger/heavier than what's in my avatar, I agree w/Dick Spadaro - go with the later flywheel.
 
The old crankshaft flange is the way to go,works every time.Good skill with your project.I think you will like the turned down flywheel v/s an aluminum one.:)
 
Many years ago I cut the rear main off of a junk crank shaft. This is then chucked into a 4 jaw and indicared to zilch. The flywheel is then bolterd on. The easiest wheel to chop is the pre42 wheel with the big lip. Cut it off and re-drill the wheel for a 10" or B&6B dON'T FORGET TO HAVE IT RE BALANCED.
 
Tom T, am I misinformed that the spacing on the 59A starter is different from an 8BA so therefore you cannot use an 8BA flywheel on a 59A?

Ajohn and Ol' Ron, no problem with the resonance or harmonics? Do you use a regular cutting tool? Why do you stipulate a 4 jaw? Will a self centering 3 jaw not work?

Yeah, I planned on this being a 2 step process. 1. Get the "bowl" cut off. 2. have the whole thing surfaced and balanced so that it looks like the later 8BA flywheel. I figured that Ford changed their flywheel design for some reason.
 
The flywheels with bowl/ring are about 1935-41 or so. They come drilled for 9" clutch, OK for a light roadster, and removing the bowl is a big chunk of weight. Often these were tapered on the engine side as well for another pound or two.
Pressure plate goes up pretty rapidly as you go from 9 to 10 and 11...I think the 10 is advisable for a car much heavier than a '32, though Ford used 9 into 1942 models I think. 11" is a monster in weight and I think entirely unnecessary unless actually used in a big truck.
'32-4 wheels also have a bowl, but the ring part is drilled for Model A type pressure plate and from memory I think there is also a lot of extra weight on the engine side.
 
"Pete, not everyone has the size lathe needed to chuck such a piece up".

True, but in any large city there will be quite a few shops that have a medium size lathe. (18 inch)
Time is money and the quicker they can do the job, the less it costs you.
Within 60 miles of me there are at least 40 shops that could do the job.

One should not worry about re-drilling a flywheel to another clutch pattern.
It is a common 30 minute job. 10 minutes to lay out and 20 to drill & tap.

As others have said, be sure to balance the flywheel seperately, then with the cover on. The disc needs to be balanced seperately if done.
This is because it changes position every time the clutch is disengaged.
 
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