So maybe restrict the ones closer. Wouldn't that work? But you would have to custom make it.

But for some reason I think I'm completely off.

 

Will the longer oil filters fit with the sidepipe headers running under there?

 

I'm using the long filter and have no clearance problems with the headers..

 

I think that I'm tending to agree with Black Shark on this one. It sounds like an oil starvation problem at the front of the engine. A high volume oil pump can pump a lot of oil...if it has a place to go. But if it is restricted, it has to have a [sump] bypass to release the excess, or it will just build pressure. I think the starvation thing may be some sort of blockage in a crank passage. When you get the crank reworked, make sure you tell the shop to blow high pressure air through the oil passages and make sure all are completely open. Some casting slag or a machining chip in a passage could cause the same kind of damage you have--especially since all of the other rod bearings are in good shape. Oh, if the crank journal saw a lot of heat (and I think it did from the condition of the bearing), the journal could have lost hardness and wear resistance. If it didn't turn color (brownish/bluish), it might be just fine. Good luck.

 

I wonder why the oil starvation didn't happen before as I've made 80 + passes with that engine...

Well, anyways.. I'll take out the crank some time this week and will have it machined..

 

You can do just the rods. If mains are fine..they will check it....don't worry about them. Doesn't hurt balance at all.


Often this stuff is cumulative....there will be a slight starvation that scuffs bearing a little each time it happens....finally it is enough to lose the bearing. Just check everything closely and find out what clearances they are using. You're running pretty hard....time to look at stuff closely when you start spraying it.


JIM

 

I'll pull the crank this week.. Is there anything specific to consider when pulling the crank?
I assume that I'll have to mark the position of crank and cam when pulling the timing chain off as the cam is probably degreed and not installed straight up.. What else do I have to watch out for?

 

Jim, turning the crank won't throw the assembly out of balance?

 

http://www.trufilter.com/

how bout one of these?

jim

 

Not enough to make any real difference. You're reducing the weight of throws slightly, but I don't think there's going to be a need to balance it again.

Oliver.....you need to take the ENTIRE engine apart. There are bearing flakes all over it inside. Take everything out, pull all the galley plugs and start pressure washing and cleaning. Bearing flakes end up on piston skirts, in ring lands, in wristpins, lifters, cam bearings, inbetween valve springs etc. EVERYTHING...I mean EVERYTHING has to be cleaned. If you don't the chunks will come back to haunt you..no doubt.


Cam will bolt right back up where it was if you line up the dots...assuming there isn't an offset bushing used in cam gear to degree it. They probably just used a 3 position gear on crank to do it.

JIM

 

Thanks!!

 

Those look nice but pricey

 

It won't change the balance at all. The material removed from the journals will be replaced by the new bearings.

 

Oliver, you said, "I wonder why the oil starvation didn't happen before as I've made 80 + passes with that engine..."

I'm not so sure you had an oiling failure at all, like you said, you've made 80+ passes without oil starvation. So why would it all of a sudden happen now? Assuming nothing got plugged up and sloshing oil has never been a problem, then in a pressurized system, if you have normal oil pressure at say rod #8, you'll also have normal oil pressure at rod#1. And your oil pressure can more than make up for any G forces your car could throw at it, were not talking Nitro stuff here. Being at the end of the line has no meaning in a pressurized system, assuming there are no unusual restriction issues happening along the way. You can't build oil pressure at all, until all the passages are full of oil, so everything basically comes up to pressure at the same time. And likewise everything will lose pressure at the same time. Imagine the pickup gets uncovered or even your oil pump falls off, everything will lose pressure at the same time, since nothing is being pumped.

What I think may have happened here, is that the rod big end stretched into a slight oval. In so doing, the hole in the big end gets larger in the up and down direction, and smaller in the side to side direction. That smaller area can pinch and grab the crank journal, and you're toast. That's why good high performance rod bearings are thinner in the side to side direction, to prevent just that. But assuming your bearings were made that way, they can only do so much for you, depending on the rods you are running. Inexpensive rods will be more prone to this that high dollar top quality rods.

I've seen just this thing occur in some stock engines over the years, that didn't make enough power to do wheelies, or for that matter, to even slosh the oil to any great degree. With plenty of oil and no problems at all, they spun a rod bearing when being raced at high rpm.

So, you may want to at least consider upgrading your rods, and as 427 Hotrod mentioned, maybe a bit more rod bearing clearance. That extra clearance could make all the difference between pinching a rod bearing and not.

 

Man, you put a lot of thought in to that.... But oil starvation can cause problems a little at a time and doesnt always happen on acceleration, it can happen when you get off the gas as well. If you drop the gas pedal and hit the brakes hard, the oil will run up the front of the pan and away from the pickup. Even though you are not at killer RPM at this point, the engine will still need oil to survive. All of this will cause wear on the bearings that might not show up for some time. What I am trying to say is. it will take more than just one time wipe out the bearings. The bearings probley get more abuse that any other part in the engine, other that lifters, and dont fail that often.

 

I'll check what kind of clearances were used on the rod bearings. I'll go with as much bearing clearance as possible for the rebuild... I know that the main bearing clearance was 2.5 or 3 thousands...

 

A spun bearing is caused by one thing..........the crank journal grabbing the bearing shell and taking the bearing with it as it spins. Two primary things can cause that, an oil failure for whatever reason, or an elongated rod big end pinching and grabbing the crank, even with normal oiling present.

Wear on the bearings will open up the clearance, causing a rod knock, but it won't cause a spun bearing out right. The only way worn bearings can contribute to a spun rod bearing, is if the knocking went on for so long, and the wear allowed to hugely increase to the point that the load carrying capacity was reduced to where the crank and bearing could come into metal to metal contact, thus grabbing and causing a spun bearing. But prior to a spun bearing from this, along with that terrible knocking, would come a noticeable drop in oil pressure. So no reasonable person would continue to run an engine showing such significant signs of distress.

 

YUP,,, I never said you were wrong,,,

 

...but because that system is flowing (dynamic) there are pressure losses along the way. Some pressure is bled off at each main & rod journal. The upstream pressure will be higher than the down stream pressure unless there is no flow (static). Even if there weren't "leaks" along the way, the down stream pressure is lower in a flowing system because of fluid frictional losses due to turns, restrictions, and just contact with the walls of the passages.

 

Yes, everything you said "can" be true, but it absolutely depends on the particular system being discussed, since there can be an almost unlimited variation between systems. If the system is designed with a straight enough main passage having sufficient diameter, and with the system providing sufficient pressure, then those losses can indeed be negligible over a reasonable distance, such as we find pressurizing engine main bearings. Therefore, it is not unreasonable to expect essentially the same pressure at the front main and at the rear main, which of course then feed the rods. To be honest, I was thinking of my Dart Big M block when I wrote that, so yes, Oliver's Chevy mouse motor may well be somewhat different, depending on all his particulars.