Any one interested in the oiling mods I did?
Here is a theory I have but cannot prove. Does an engine oil pump pressure feed the rod bearing or does the centrifugal force of the spinning crankshaft throw the oil in the crank oil cavity at the rod bearings. This was Sanborns theory that the slotting of main bearings gave a longer dwell time for that passage to fill up.
I ask this because I have had failed 2&4 main bearings with no sign of rod bearing damage. It was explained to me that because I did not restrict oil going to the rockers, my main bearing oil did not form hydro dynamic wedge because of inadequate pressure, yet I saw no signs of rod bearing trouble. Could it be that because the crank passage was filled but not pressurized, that centrifugal force still adequately supplied the rods?
You have to increase the dwell time IF the oil timing is off. That’s the band aid. Like full groove mains. You are getting oil to the rods all the time.
If you read that paper that Phreakish posted they discussed putting oil in at TDC. Or shortly after. Pretty interesting.
Again, I use the SBC a my example. They don’t need full groove mains, more dwell time or any of that, because the oil is there, full flow, full pressure at the correct time.
Obviously if the big end of the rods don’t stay round, or they have too much clearance (almost as bad as too little clearance) the pan sucks or some other issue, that system is pretty much bullet proof, even if you oil the mains after the cam the OE stuff did for decades.
EDIT: forgot to mention this question, because it has me scratching my head. The mains get oiled first. So how the mains get starved and not the rods? Or did they both get it.
I think I said this earlier but I prefer to groove the cam and restrict the oil in 2 and 4 rather than just restricting oil there. You can cut the others back more, but 2 and 4 can still get cut back quite a bit if they are getting full time oil.