Checking Connecting Rod Oil Clearance

[JGC403]

I'm checking the oil clearances on the motor that I am building. I'm checking the oil clearance on the rods next. The rods that I'm using have the alignment sleeves on the caps. I remember the caps being difficult to remove from the rods when I got them. I'm checking oil clearance with plastigauge. So after I torque down the rod caps on the crankshaft, how do I remove the caps.

 

[moper]

Plastigage is better than nothing, but measuring is best.
However, if it's all you have I commend you for taking the time to check.
Place the plastigage material on the center of the cleaned and dry upper bearing shell - that's the "lower" one when the engine is upside down. Then torque it properly in steps. It's critical the bearing and journal surfaces have no lubrication at all for this to be accurate. Then loosen the bolts and using the butt end of a hammer or mallet, softly tap the pin boss of the piston. It should pull the cap right off the sleeves and leave the plastigage intact to read. It's best if you mock up the lower end without the rings and do one cylinder at a time. You want to not have to rotate the crank since the bearings are dry.

 

[JGC403]

OK I see. Thanks. I figured it would be to much of a hassle to take everything to the machine shop to have them measure everything since I don't have the right tools to do it. Plastigauge would be good enough.

 

[moper]

Well, it will give you an idea of the status of the journal. But that's about it. It won;t show taper or out of round conditions which cna be worse than too much clearance. But as you say, better then nothing.