[Joe K]

A couple of things of my experience.

1. Modern crank grinders "squeeze" the crank too hard between centers. This bows the crank and makes for an offset center. I discovered this when I found the crank couldn't be turned easily in the block, even though the line boring was the right size, the individual bearing clearances correct, and shims set up correctly. The solution was found in having the crank "straightened" which is an action watched in some trepidation and perhaps even a mild bit of terror. Oh - and magnafluxed and checked for cracks after straightening.

2. Modern crank grinders grind primarily for use with inserted bearings. The surface roughness of the ground journals is entirely too course since in insert journals the load is primarily taken by oil pressure - the crank only touches the bearings on startup (and yes, occasionally or more than occasionally on heavy loading.)

3. The "centers" of cranks (dimples at the end of the crankshaft where the centers go) start their life at "geometric center" but as the crank wears, similar to the rods albeit less, the journals get "egg shaped." You may or may not want to grind to remove the egg - although in doing so you may remove more material from the journal than is absolutely necessary to make it round. Better perhaps to use what remains of the journal, fix it in a lathe using a steady rest at journals 1 and 3 and "re-cut" the center, which is a job not too difficult with a regular lathe tool ground for clearance. (be sure to skim cut the flywheel flange and indicate flywheel after bolting in place.) Some may object to this as it brings a crank to a potentially different stroke and does introduce error to the flywheel, but the purpose of all of this is driving pleasure - and cranks and strokes CAN vary without materially affecting their function.

Best would be to leave it all in the hands of an experienced Model A engine rebuilder. He will have a routine commonly used and with which he is comfortable with.

Joe K