The Ford Barn

daren007 · 12-08-2019, 05:15 PM

Disassembled my "A" engine for issues. What I did not expect to find was problems with the main bearing Babbitt. I would estimate about 3000 miles on rebuild including crank regrind and new Babbitt. the center main cap has a piece broken off about 1/4 of the total area. (Sorry no pictures) I pried the remaining Babbitt with a pocket knife to see if the material was brittle. The material is not brittle however the rest of the bearing came off the cap. There is evidence of oil between the bearing and cap. I tried the front main cap and the bearing came off as well with a film of oil between the bearing and cap. The rear cap is ok. There is a nasty vibration at around 800-1200 rpm range that I try and drive through as soon as possible. I do not lug the engine plus I am careful not to advance the spark too much. There is no evidence of detonation on the spark plugs nor pistons. Can someone help me here on what happened. Daren

12-08-2019, 05:15 PM	#1
daren007 Senior Member Join Date: Apr 2015 Location: Saint Cloud Mn Posts: 745	Babbit woes Disassembled my "A" engine for issues. What I did not expect to find was problems with the main bearing Babbitt. I would estimate about 3000 miles on rebuild including crank regrind and new Babbitt. the center main cap has a piece broken off about 1/4 of the total area. (Sorry no pictures) I pried the remaining Babbitt with a pocket knife to see if the material was brittle. The material is not brittle however the rest of the bearing came off the cap. There is evidence of oil between the bearing and cap. I tried the front main cap and the bearing came off as well with a film of oil between the bearing and cap. The rear cap is ok. There is a nasty vibration at around 800-1200 rpm range that I try and drive through as soon as possible. I do not lug the engine plus I am careful not to advance the spark too much. There is no evidence of detonation on the spark plugs nor pistons. Can someone help me here on what happened. Daren