ClassAct wrote: ↑Tue Nov 26, 2019 11:20 amWarp Speed wrote: ↑Tue Nov 26, 2019 10:16 amI can't really go too much into the oiling strategy we use, but I know one thing for sure. If the theory Classact has on oil timing were true, none of our engines would make it through a single pull on the dyno.
As I've said all along, look elsewhere for the problem, because thats NOT it!
Once again, the OP didn't ask about what you do. The actual question was about a 3/4 groove main bearing for a BBC. He wasn't talking about the latest, greatest oiling system you use.
The sad thing is, the oil timing issue is well known. How it's done today at the NASCAR I can't say and really don't care. Most guys on here will never deal with it.
A hydraulics engineer, who wasn't indoctrinated in automotive engineering, developed the system needed o fix the oil timing on engines where it's off.
Again, I don't know anyone, not a single guy I can think of, who actually runs RPM's at 8k or more who hasn't had Rod bearing oiling issues with the OE type oiling system. I know that many guys claimed they did/do it, but data logging proved most of them never saw the high side of 7600.
The oiling system of an OE engine is essentially the same for every brand out there, with very small differences. Yet, the SBC was the ONLY one that oiled reliably at virtually any RPM you had the balls to pay for. And none of the rest of them would even get close and to do that took a bunch of modifications and even then, reliability was a big question mark.
So take two blocks and cranks, a SBC and for fun, let's use a BB MoPar which is just as bad and set them side by each and look at the differences. Virtually no differences, except where the oil feed hole is located.
I had the good fortune to work with a local Comp racer who eventually set and reset several times his National Record. I also looked at most of his runs right off the data logger. He shifted at 9800 and crossed at 10,200-10,400 depending on conditions and clutch tuning etc. Did that with a wet sump and an oiling system that was literally untouched. His blocks didn't even have priority main oiling until he had set and ready the record several times.
You're not going to do that with any other brand.
So figure out what the difference is.
To the OP, you don't need more than a half groove bearing for a BBC. Or a SBC. Anything else, use a half groove bearing at your own risk.
Man, I'm really sorry if facts are getting in the way of your theory, but it is what it is.