Flywheel

[daren007]

I remembering reading something awhile back about installing a model A flywheel on a model B crankshaft. It seems the A crankshaft has a radius on the outer edge where it fits into the flywheel where the B does not. I was told the A flywheel has a radius where the crankshaft fits to accommodate . With this in mind I believe you have to machine the radius out of the A flywheel or the model B crankshaft will ride up on the radius. Can anyone tell me what they have seen when this happens.

[Bob C]

I've never heard that about the radius. The A flywheel will not fit the B flywheel
housing and pan.
See Vince's site. http://www.fordgarage.com/pages/flywheels.htm

Bob

[daren007]

You have to modify the B pan then you can use the A housing and Flywheel.

[J Franklin]

I would just instruct the machine shop to fit everything properly if there were any differences.

[daren007]

I am trying to confirm that if you install a A flywheel on a B crankshaft that you have to do some machining. Next question I have is if there is a interference what happens if it's not caught before running the car. I suspect there will be run out because the flywheel cannot fit properly causing a vibration. Has anyone experienced this.

[Charlie Stephens]

Sponsored Links (Register now to hide all advertisements)

Originally Posted by daren007

I am trying to confirm that if you install a A flywheel on a B crankshaft that you have to do some machining. Next question I have is if there is a interference what happens if it's not caught before running the car. I suspect there will be run out because the flywheel cannot fit properly causing a vibration. Has anyone experienced this.

There is not problem putting a B flywheel on an A engine engine. The problem comes if you try to use a B transmission with the A flywheel. The A flywheel will rub the B transmission case unless the flywheel is cut down.

Charlie Stephens

[Dave in MN]

Originally Posted by daren007

I remembering reading something awhile back about installing a model A flywheel on a model B crankshaft. It seems the A crankshaft has a radius on the outer edge where it fits into the flywheel where the B does not. I was told the A flywheel has a radius where the crankshaft fits to accommodate . With this in mind I believe you have to machine the radius out of the A flywheel or the model B crankshaft will ride up on the radius. Can anyone tell me what they have seen when this happens.

I thought I read this a number of years ago also...I also can not remember where I read it. Four years ago, having the opportunity to re-build a couple Model B engines, with this memory in my head, I called three individuals I consider to be very knowledgeable regarding engines and flywheels. They all told me this interference claim was not true. Not trusting, I went through my inventory of flywheels and crankshafts and did not find one case of a radius on a flywheel that would hold it away from the crankshaft flange. At the time, I did not have a Model B flywheel to check.

When I saw your post yesterday, again, I checked the crankshaft mounting surface on 8 Model A flywheels and one Model B flywheel and confirmed they all have a recess cut at the outer edge of the mounting area. There may be a radius down in the recess that I can not detect but it is/would be recessed below the flange mounting surface. See the photos of the B & A flywheels below.

I checked 4 counterweighted Model B and 8 Model A crankshaft flywheel flanges and they all had chamfered edges. See photos below. I lightly face the flywheel flanges of the crankshafts when they are reground so it slightly changes the amount of chamfer. Yesterday, I specifically looked for original un-faced crankshaft flanges to determine the amount of chamfer and found the amount of chamfer varied.

So in conclusion, after checking twice, I think what we both read back then was "bunk".
Good Day!

[Jim Brierley]

As Charlie Stephens says.

[daren007]

If you are correct that is good news. Thanks. Daren