The Ford Barn

Ken MA · 01-25-2020, 12:47 PM

Trying to track down a thumping noise on this motor accelerating under load.
Motor was rebuilt 2 years ago and driven 2000 miles.Pulled the pan and made some measurements

Reground Crank .020
Rebored with new pistons .060
Re-babbited mains .0015-.002
new babbit rods .002
Crank end play .009

There is a lot of side to side wear on the rod bearings .010-.024 between the thrust end of the rod bearing and the crank . Thrust surface on rear facing #2 bearing is worn thin. What is an acceptable end play clearance on rods? Is #2 pounding against the crankshaft causing the noise, or is the .009 crank end play causing the problem? Before this block was rebuilt most of the babbit on the original rods was worn away . Any ideas on the cause or fixes is appreciated!

01-25-2020, 12:47 PM	#1
Ken MA Junior Member Join Date: Jan 2014 Location: Massachusetts Posts: 27	Connecting rod end play Trying to track down a thumping noise on this motor accelerating under load. Motor was rebuilt 2 years ago and driven 2000 miles.Pulled the pan and made some measurements Reground Crank .020 Rebored with new pistons .060 Re-babbited mains .0015-.002 new babbit rods .002 Crank end play .009 There is a lot of side to side wear on the rod bearings .010-.024 between the thrust end of the rod bearing and the crank . Thrust surface on rear facing #2 bearing is worn thin. What is an acceptable end play clearance on rods? Is #2 pounding against the crankshaft causing the noise, or is the .009 crank end play causing the problem? Before this block was rebuilt most of the babbit on the original rods was worn away . Any ideas on the cause or fixes is appreciated!