69MOPE
Well-Known Member
How do the wrist pins get oiled when using aftermarket rods without oil squirt holes?
No squirt hole in aftermarket rods?
- Thread starter 69MOPE
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moper
Well-Known Member
The oiling holes in the factory rods were for the cylinder wall. The pins are oiled by splash in the bushing, and from the oil scraper ring stack in the piston. Modern ring science says less oil on the walls is better, so the rods and some rod bearings have no passage.
C130 Chief
Mechanical Genius
The oil spray holes also lubed the cam and helped cool the pistons.
In a high performance, high RPM engine crank windage is sufficient and extra oil on the cylinder walls could overwhelm the rings causing detonation. So replacement "performance" bearings generally don't have the notch. In a street engine which may spend extensive time at idle or low RPM, the cam can run dry.
I am convinced that a lot of the cam/lifter problems that get blamed on lower zinc levels in current oils, are a result of poor lubrication. Late Jeep 4.0L engines that spend a lot of time "crawling" seem to suffer a lot of lifter and OPDA gear failures. Those which are highway driven last much better.
In a high performance, high RPM engine crank windage is sufficient and extra oil on the cylinder walls could overwhelm the rings causing detonation. So replacement "performance" bearings generally don't have the notch. In a street engine which may spend extensive time at idle or low RPM, the cam can run dry.
I am convinced that a lot of the cam/lifter problems that get blamed on lower zinc levels in current oils, are a result of poor lubrication. Late Jeep 4.0L engines that spend a lot of time "crawling" seem to suffer a lot of lifter and OPDA gear failures. Those which are highway driven last much better.
bOb shingler
Well-Known Member
if you're talking about the small end on the rod, you drill you own holes like the mopar performance/direct connection manuals suggest to do.
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