Think about how and when the hydrodynamic wedge is formed between the bearing and the crank to carry the load of compression. You won't be squeezing oil into that interface if you don't get the oil in there BEFORE the load goes up.swampbuggy wrote: ↑Fri Dec 06, 2019 6:47 am With all due respect to you Classact, i will ask you this question. You have been stating (expressing) the extreme importance of the hole in the crankshaft main journal lining up with the hole in the main bearing/engine block. The question is------------WHY is this so important, what does this allow to happen that didn't happen 45 degrees prior to the holes lining up ? Please give detailed/complete answer. Mark H.
So I went back and looked through my notes. Most of them are from 1984 when I learned it and 1992 when I listened to a bunch of morons who wanted it changed. The ~ 70 degrees ATDC is correct. It has to be close to that. Otherwise you won't get the hydrodynamic wedge won't be formed (or will be way too weak for lack of a better term) to keep the bearing off of the crank.
I also found in my notes several phone numbers of Super Stock guys who were using this system since at least as early as 1979. Some of the numbers a no longer good, one guy has since died and one number worked. So I called and talked to him last night.
Once we started talking, we remembered we had met at Chrysler race in 1996 and he was pretty pissed at what he saw. I had changed the system for two reasons. One was to get filtered oil to the bearings 100% of the time and the other was to make the oil pressure externally adjustable. He didn't like the fact that most of it was exposed. He was one of the original guys who PAID to learn why they were killing bearings.
Back then, they didn't have much for block selection so they had to figure it out. And that's how they did it. He said Chrysler fought then tooth and nail about publishing how to correct oil timing. He said none of the guys doing it were capable of getting anything published so they wanted Chrysler to issue a bulletin about it and they refused. So to this day, the majority of Chrysler guys (this is the same issue the BB MoPar has) have no idea how to make RPM and not kill Rod bearings. It's sad really.
And don't get me started on the bastards at Chrysler who refuse to acknowledge that there is an OIL TIMING ISSUE getting oil to the rocker arm adjusters!!!! That's an oil timing issue as well. But if we go down that road, warp will be in a rubber room eating his underwear.