Help! Finally got my 51 Merc engine completed. Last step, installing my Bubba dizzy, when tried to rotate, the crank was frozen solid....after starting to tear things apart, discovered the flywheel was jammed against the block. My machine shop folks would not lighten a merc fly, so I got a lightened FORD unit from a guy who supposedly knows his stuff. Anybody have info why a Ford flywheel would not fit the Merc block without huge rubbing? I do think we could mill off about 1/8 inch and it would clear. Or use a spacer between crank and wheel?? Ideas??
The problem is '48 and older and '49 and newer. I bet you have the older style flywheel. I think the ring gear is different also. Solution is find someone that will lighten a steel flywheel or buy an aluminum one. The aluminum flywheel will be lighter than you can get by cutting down a steel one. If you buy an aluminum flywheel, watch so that you get one with an insert for the clutch disk. I went the route of a new aluminum flywheel for my 8BA and have a used one with a brass insert in a 59BA. They make quite a difference. Neal
'49 and newer 8ba style flywheels have bolt holes for the pressure plate that go all the way through the flywheel. '48 and earlier have blind bolt holes for the PP. The older flywheels won't work on the newer flatheads and vice versa.
I have an aluminum flywheel in my 39 and would not do it again. It is too light for street use. At lower speeds I get some "bucking" due to the light flywheel. I would go with a lightened steel wheel. I'm sure it is compounded by the hotter than stock cam.
I think adding to my confusion is the bolt holes DO go all the way thru, but that would have been necessary I think because the old fellow who lightened it took a lot of meat off the clutch face side of the wheel. I will find the post on Hamb that states the "drop" on the crank side, we are seeking a 59A wheel to verify what is wrong. The little lip at edge drags on the block, no drag on the oil pump bolts. thanks for your advise and help. We will get there!
Another option is to buy a Centerforce steel flywheel, which is about 9 lbs. lighter than a stock iron 8BA/8CM. These are balanced, multi-drilled for Long and B&B/diaphragm, and include a ring gear.
I wonder if anything got wrecked when you tightened the flywheel bolts, which pulled the crank back in the block.
If anyone on right now has Ron Holleran's book "Nostalgia" handy, he illustrates an easy way to measure the things from crank face to friction face and conclusively ID the things.
The Jalopy Journal
