When to machine a crank

[Phil-mar Farms]

An old tractor jockey told me to check the cam
bearings to improve oil pressure. He said that tractors
got many in frame overhauls but the cam bearings
were often left out

 

[BarnyardEngineering]

Unless you remove the crank from the engine all you can do is guess on the main journals. There is no way to get a micrometer in there to measure the mains inside the block.

Rod journals, you can disconnect the rod and push it up out of the way and take your measurements. Take two measurements at 90 degrees to each other minimum. That will give you an idea how out of round the journal is.

IMHO you can't do any harm rolling in new bearings as long as you stick to the same size bearings you took out. You may not do any good but you won't do any harm.

 

[J.Wondergem]

I have a BN from my uncle's estate. He put new bearings and rings in it and it seems to run real good.

 

[560Dennis]

Heres a tip for you.

They like to like to take the rod caps out and grind the cap down. Put the old bearings back in .Tell you its been overhauled with a can of
rattle can paint all over . Brand new !

So when you put in your nice brand new bearings into the 300 you torque the rod caps down and it will not turn over . Id check your rods
,so measure everything .