Bearing clearance

[Kohnke Rebabbitting]

Originally Posted by russcc

Question for the engine builders. In the process of assembling the 59L block, 3 & 5/16" bore, Merc crank, ground 0.010 under, balanced rotating assembly. NOS Federal Mogul 0.010 under main bearings.
Vern Tardel's book, page 143, Main bearing cap clearance 0.001-0.001.5, using plastigage
Ford Motor Company V8 engine repair manual, 1948, Page 131a, Main bearing liner clearance 0.000-0.003
Ron Holleran's book, Nostalgia, Page 8., crank clearance 0.001-0.003, "grind or polish to the low side".


Opinions on main bearing clearance. Is their an advantage to having a little more clearance ? Thank you Fordbarners.

Main and Rod clearance should be .001 per inch of crank. a 2 inch crank should have .002 thousandths clearance, or plus a half, .000-50 tops.

At .001, or .001-50, you will be pushing usable bearing material out of the way, and wasting it, on a 2" crank.

From cold to hot, a 2" crank will swell .002 thousandths.

Herm.