lifter galley crossover tube

To answer Duanes post:

I should have pointed out I don't normally like cross drilling a crank. There is usually never a need for it. We are discussing oil timing so the cross drilling is a function of that. In fact, with factory oil timing, cross drilling a crank for high speed use can actually pull oil from the rods. Not good and counter productive. There is also more that one way to cross drill a crank, and the system that has the cross drill intersect at the feed hole is far better than a cross drill that intersects in the middle of the feed hole. That is very bad, as the centrifugal forces pull oil back from the rods. All this is just for information purposes and I never suggest cross drilling ANYTHING unless you have a specific reason to do it. So, my bad for not adding more information about cross drilling.

As for the 70 degrees past TDC that's a fairly involved story. My dad had a very close friend who was an engineering whiz. He worked on oil refining plants and nuclear power plants. He went all over the world to do the engineering on stuff like that. His specialty was hydraulics. He also straightened me out on mechanical fuel injection. That's another story.

Anyway, I spent all of 1983 building a Tunnel Rammed 14:1 340. I had pcar heads so I knew it would be tough to make power at 8000. Luckily, I had found an over the counter T/A block with 4 bolt caps and an 8 bolt crank and Carillo rods. I spent an assload of 1983 dollars to get it done. I had a Cam Dynamics roller with Engle lifters. At that time, there weren't any dynos close so it went in the car. Larry (the engineer) happened to be in town and went to the track with us. I spent the day sneaking up on it. I started shifting at 7000 and worked my way up. The last pass was going to be shifted at 8200. At the top of second, it unloaded the 3&4 rods right out of the block. Luckily, I saved the block and crank, but lost 2 rods, the cam and several valves.

That's when Larry told me I would always fight Rod bearing issues if I didn't fix the oil timing issue. That was the first I'd heard of it.

I heard through scuttle butt a local guy I'd never met was selling a complete W-2 engine, with T/A block, 8 bolt crank and Carillo rods. I thought it was BS but I went to look at it. It was exactly what is was supposed to be. The difference was he had corrected the oil timing. I almost fell over. It was about six months before I'd heard of oil timing and here was guy selling out who had the same issue I had.

We pulled the pan off and there it was. I had spent the better part of 6 months trying to figure out how to fix the oil timing issue and here was a guy who had DONE it. He had paid an engineer to figure it out.

As I've said, his was a simple, effective fix. It was just that not all the oil was filtered all the time. The oil was filtered but the oil going to the mains was before the filter.

I took about 30 pictures, had them developed (yes, I'm that old) and sent them to Larry. He said it works, just make sure the crank is cross drilled. So I drove over with a check and pulled the cap. Sure enough, it was cross drilled.

I beat the crap out of that thing for years. In 1998 I bought two X blocks and set the T/A block aside. I eventually sold the block to a guy doing a clone T/A car. I still have the crank and W-2 heads from that guy.

I eventually changed the system so all the oil was filtered all the time, but that was the only change I ever made.

Before I started doing all my own machine work, I had 2 different machinists who didn't understand how oil timing works talk me into small changes. I paid a big price for those changes. Just like lock work, 3&4 rods would come out. By then, I was running aluminum rods. I then put it back just like it was and the carnage stopped. So I've proven it works.

Larry died in 1992. In 1990 he sent me a 1950 engineering book that explained how oil timing works, and how they came up with the about 70 degrees after TDC was when full pressure and flow needed to be at the rods. I spent an hour last night looking for the book. I have over 1100 books in my library and I didn't see it. I may have loaned it to my brother, or a friend in Arizona. If it went to Arizona, I'll never get it back because he died in 2015. I'm sure if you look around you can find an automotive engineering book that will explain it.

I do know that David Reher and David Nickens know it. I was talking to DR in 1989 in Seattle about it. In 1998 I had the opportunity to mee Davis Nickens at PIR when he was there with his PS truck racing Bart Price. I also me Larry Morgan and knew he was going to a Dodge before almost anyone else.

I haven't talked to DN since about 2005 but we had some long phone conversations about PST, how Dodge didn't want to budge on body shape, even though it was killing the Dodges. He also agreed with the 70 degree oil timing. So I know it's known out there.
That's the short version.

As for bearing grooves...their purpose is to get the flow started out to the rods BEFORE the need is there. The groove really only needs to go past the main feed hole about 30 degrees. But it it's easier to cut the groove around the entire bearing. The reason no one uses full groove bearings on chevies is the oil timing is correct.

A full groove bearing let's oil go to the rods all the time. If you are picking the pepper out of the fly poop, this is a bad thing. Oil going to the rods full time increase oil use and we all know the less oil flow you need, the smaller the pump you can use and still feed the system. And, as RPM goes up, the leaks become greater. All that oil gets wrapped in the crank. So that means power getting eaten up. That's why most guys don't ever use full groove bearings. If the timing is correct you just don't need them. Unless it's a Chrysler and you are trying to fix the oil timing. I always use full groove bearings on Chryslers. Always. I'll give up the power and windage looks to keep the rods in the block.

How they came up with the 70 degree number was that is ABOUT where max load on the rod bearing is. It depends a bit on Rod to stroke ratio and a couple other things, but max load on the Rod bearings is always about 70 degrees past TDC. That's why you need full pressure and flow at that time. Chrysler sends the oil to the rods too soon. So by the time max load occurs, the full pressure and flow oil is past, and all you are getting is the oil that goes around the groove. And it's not full pressure or full flow. It doesn't take long for the rods to unhook from the crank. At 8000 plus RPM, the damage is catastrophic.

The biggest thing with Chryslers is full groove mains, stop the oil leaks at the lifter bores, use a high volume pump and the biggest pickup tube you can fabricate or buy. That will get you safely to 7500 or so. After that, you are asking to kill parts and you need to correct the oil timing.

I can safely say I've never seen a GM block without the correct oil timing. Ever. The early pcar blocks didn't have priority main oiling apbut the timing was correct. Certainly, the oil took a most circuitous route, and getting oil to the mains before the lifters makes the best sense, it only means you can use a smaller pump and have less windage loss. All good things if your trying to run down Jason Line for the money, but if you are just trying to make power at high RPM and keep the rods where they belong, oil timing is what makes them live.