IMHO, nothing good can come from losing oil pressure at high RPM. That is why I have mine tore down.

 

You really want your oil pressure to stay steady in the higher rpm range in order to supply the proper flow of oil throughout the engine. So figuring this problem out is a very good idea but if you are worried I would cut your oil filter open to inspect. Try the Wix oil filter and let me know what you find.

Chad

 

I have done this. We saw some bright silver specs that were attracted to a magnet. Not a severe amount but it was easily seen. Cant be bearing material or piston material. If I had to guess, maybe slivers off of the first oil pump gears when they sucked air when the pickup fell off.

I inpected the oil pump drive gear too. Nothing unusual. Cant be the titanium retainers.

 

If you do not see copper colored material and a lot of it then I would doubt that you are having any bearing issues plus if you are having bearing issues you would see your idle oil pressure dropping over time.

 

I think my next course of action is to pull the pan, check all the bearings and maybe try a different oil pump.

Let me ask another question. I recently noticed I had heavy oil coating inside the intake. I pulled the intake, cleaned it and some minor oil coating returned in 20 miles. I have ruled out the oil coming through the combustion chambers, no smoke out the exhaust. Its not coming throught the fresh air hose on the right valve cover, it has a filter and no evidence of oil. The PCV metal line and PCV shows evidence of oil.

I recently installed a catch can on that line and there are minor amounts of oil in the catch can so it is doing its job. Do you run into oil coated LT1 intakes and what has been the reasons for it and the solutions?

 

I'm not an expert, but couldn't this be a problem? As I understand it, oil pressure is measured as pressure since it's easy and convenient to do, and is a good enough indicator of flow, which is what really matters. Pressure is a function of both oil viscosity and oil pump RPM, but flow is mostly just a function of oil pump RPM. You might get a cold PSI of 70 at idle and that's fine, but when your approaching 70 PSI at WOT with the oil up to temp, even though the pressure is the same it's flowing much much more. I'm thinking that trying to force that much volume through the filter at a high rate could cause cavitation at the pump since it can't bypass the filter to keep the flow up, or maybe it's forcing the elements inside the filter apart which causes the pressure to momentarily drop? Might be worth at least testing, the bypass is there for a reason, to release excessive pressure, this could be a side affect.

 

It would be a lot of work for a little change, but I'd be interested in seeing what would happen if he went back to a standard pressure spring. That Chevy High Performance article states that too high a pressure will introduce air into the system...although I'm not sure how. I'm not completely sure how the oil pump bypass works. I thought it just dumped the excess into the pan, but I seem to remember reading that it is recirculated into the inlet of the pump somehow.

This is unrelated, as his adapter bypass is blocked off, but I've only recently figured out how the adapter bypass works. As best I can tell, the bypass in the oil filter adapter works by the pressure being balanced on both sides of the filter, input side and output side(I thought it was a spring pressure thing at first). Once the pressure unbalances due to a clogged filter, the bypass opens because of the drop in pressure on the output side of the filter and rise in pressure on the input side.

 

I believe he is on to something. Change the filter and see what happens. The behavior you are describing to me sounds like either oil airation(sp?) or an oil system pressure bleed-off. I also believe there is a modification you can do to bypass the oil bypass and force all the oil through the filter. You may want to try that too. I don't know the process but it's a standard SBC capability. Food for thought.

 

my stock intake when i pulled it off was filled with oil. the pvc connects to the throttle body and all the vented air and oil vapor is just run through your engine. inside the crankcase when your engine is hot theres lots of oil vapor and when it vents through the PCV it condenses on the colder throttle body and drips down in your intake and condenses on everything it touches and drips down your air inlet hose ect.

 

Good discussion guys.

I have the old filter "guts" and I dont see any copper bearing material in it but I do have the tiny bright silver specs. The specs did not appear to come from the old oil pump. The oil pump drive gear was not hevily worn but what wear it did show was very rough in appearance. I would have expected more smooth wear marks so maybe that could be the source of the specs.

I am going to remove the plugged adapter bypass and install a new one with the functioning relief valve since its easy and cheap just to rule it out. That is the only custom thing or wild card in the oil system. Too many people have run the white spring and the 10554 pump with great sucess so I am having a hard time thinking they could be the problem but at some time I will have to revisit the pump.

 

The only reason I mention the white spring is because that was one of my modifications(rockers, cam, pushrods, and lifters were the others)....and I have the same problem to a lesser degree. Never had the problem before and my bearings are within factory spec...no abnormal wear....except for the grooves in my #1 main. It's clearance looked great, but just some grooves cut in it(speculation is trash or glass bead from factory).

If you would rather not try it I completely understand. I am going back to the standard pressure spring, so I can let you know how it works. However....it appears I may be sometime in June before I get everything back together.

 

I am willing to give it a try but it wont be right away. The adapter I can do quickly.

 

When I talked to Chad, his first piece of advice was to overfill my oil by a quart and see if that fixes the oil pressure drop I see around 5K. He said this has worked for a lot of the people who report this problem to him. I added only 1/2 quart and the problem is essentially gone. Out of a dozen or so full throttle sprints I only saw the pressure drop twice and it dropped to about 50 psi instead of below 40 like it was before.

 

If you go back to post #1, he tried overfilling the oil by 1/2 quart and it didn't change anything.

 

It has been suggested by others that a better oil pan with better control could resolve the problem. Since that is a $300 plus fix, im focused on troubleshooting everything before going to the pan. Sounds like that might be the total solution to your problem.

I did overfill my oil and it did not help my pressure drop issue at all.