[H. L. Chauvin]

In reply to above #10, a hands on forensic evaluation would be the the most prudent way to determine the probable cause(s) as opposed to trying to guess at looking at photographs from miles away.

As hinted above, it could be a lack of engine balance, bent crankshaft, Babbitt problems, or whatever.

Model A engine rebuilds were done very often in years past, e.g., in the 1940's, Sears rebuilt and traded thousands of Model A engines with no problems because of having trained individuals and proper tools & equipment.

I have personally experienced at both U. S. Army Depots in Utah and Alabama thousands of military engines for tanks, jeeps, etc., that were professionally totally rebuilt with no problems because of having trained civilians rebuilding same with the most modern expensive equipment available ...... they even successfully grind the valve type faces of the revolving tank turrets that get beat up after firing rounds ..... the whole tank body, with tracks, is turned 90 degrees sideways and rotated on a fixed cutter ...... a rebuild sight to see.

I just find it sad to see so many Model A owners experiencing engine reassembly failures ...... but many should be commended for humbly reporting such problems because Model A owners can help other Model A owners to be cautious.

Never a bad idea to call Mr. Kohnke and others for Model A rebuilding advice.