When assembling an engine and the main or rod bearing clearances are too close, how would you adjust it and vise versa if it where too loose, what would be done to correct it.

Jim
New Lenox

Hi Jim,

It depends on how much clearance either way that you are trying to adjust for. If it is .001" either way the easiest way is to buy undersize or oversize bearings. You can also use 1 "standard" insert and 1 "oversize or undersize" insert to change the over all clearance by .0005" to really dial in the amount you want. Another method for adding clearance is to have the crank polished but never more than .0005" or it is asking for trouble keeping the journals "flat". Anything needing more adjustment than the methods I listed need to have the crank ground to the next undersize and include the amount of clearance you want when ground. Hope this helps.

Jay Roeder