Whats the bearing clearance , oil wt , and oil temp ?

 

stock rebuild with stock style bearings...002-.0025 clearance running 15/40 rotella

 

That's about what it is in my son's....sbe factory everything else but oil pump. Been ok thus far and no turbo oil consumption. I will say the pressure drops a bit when hot.

 

Put 10-30 in it

 

If it isn’t a crazy build and close to std bearing clearances the stock Ls engines use 5-0 w30. I have seen a sbc that high before and then the opposite with less than 10 at idle. Both lived long lives. Try a good lower viscosity and maybe an oil temp gauge for future reference. The lower viscosity will free up some hp, relive stress on the pump and a good synthetic is more stable across temperature ranges.

 

HV pump in stock clearances. Ya, expect high pressures.

 

If the oil is staying where it belongs, run it.

 

An oil pump will pump a constant X volume at a specific RPM. If the oiling system is restrictive, the pressure will be high. That's why they have a pressure relief valve. Obviously pressure will be higher with higher viscosity oil. As someone suggested, you probably need to use a lower viscosity oil.

Assuming the correct oil viscosity for the engine's bearing clearances is used, typically when a cold engine is started the oil pressure at idle will be close to the oil pressure relief valve setting and as the oil heats up is will drop below the pressure relief setting but when the engine revs up it will go back to where the pressure relief setting is or slightly higher.

The setting on my SBF HV pump is around 65psi. I can tell because that's where the pressure is at cold idle but when the engine oil is hot (200deg F or higher) the idle pressure drops below 40 but when the engine revs up it goes to 65-70psi. This pressure indicates the oil relieve valve is closed (or almost). The key here is the higher the oil pressure is above the relief valve setting the less flow you have thru the engine. With too high a viscosity oil, the high pressure indicates the pressure relief valve is completely open and bypassing oil flow that you want running thru the engine.

 

The only potential negative is aireation of the oll if volume thru the bypass valve is excessive. The modern engines that drive the oil pumpnoff the crank are not really a problem like it would be if it was a SBC or SBF, etc that is driving off the distributor gear and oil pump driveshaft. In these engines it causes excessive distributor gear wear and the SBF is known for breaking oil pump drive shafts at elevated pressures. We commonly run 100+psi on dry sump engines on purpose. I would consider a lower viscosity however, if it has rock solid oil pressure at high rpm I would probably just leave it alone. Run a good oil filter like a Wix Racing or K&N that will not risk rupturing the filter like some cheap filters are known for and enjoy the reassurance high oil pressure gives you. I'll take too high over too low any day. Just my $0.02

P.S.
There are a couple Melling pumps that offer a 85psi bypass spring like is used in the factory COPO engines. One is standard volume, high pressure and the other is high volume, high pressure.

 

The only potential negative is aireation of the oll if volume thru the bypass valve is excessive. The modern engines that drive the oil pumpnoff the crank are not really a problem like it would be if it was a SBC or SBF, etc that is driving off the distributor gear and oil pump driveshaft. In these engines it causes excessive distributor gear wear and the SBF is known for breaking oil pump drive shafts at elevated pressures. We commonly run 100+psi on dry sump engines on purpose. I would consider a lower viscosity however, if it has rock solid oil pressure at high rpm I would probably just leave it alone. Run a good oil filter like a Wix Racing or K&N that will not risk rupturing the filter like some cheap filters are known for and enjoy the reassurance high oil pressure gives you. I'll take too high over too low any day. Just my $0.02

P.S.
There are a couple Melling pumps that offer a 85psi bypass spring like is used in the factory COPO engines. One is standard volume, high pressure and the other is high volume, high pressure.

Yes
I forgot where, but there is a melling technical video where they talk about this.

The old myth of "pan sucking dry" especially on LS's they believe is actually from the internal bypass. Basically with the high volume pump at high rpm, the pump is pushing so much more oil than is needed, it just tries to bypass everything until it's just pumping froth.

The bypass in the melling pumps returns directly into the inlet section of the pump casting. And this over pumping thing can definitely become an issue.

A thinner oil would be the right choice here. Should lower that pressure so the pump doesn't try to bypass as much (reducing potential aeration) and also lower viscosity will naturally be less prone to holding aeration (how much so depends on a lot of things but in "general")

 

The only advice I can confidently pass on is "DO NOT USE AN ORANGE OIL FILTER".

 

True years ago my Buddy may he RIP had a low oil pressure problem on his BBC!!After trying this and that no change until he took the orange filter off and replaced with a different brand problem solved!!A couple years later IIRC our other buddy had the same problem with his BBC my buddy that passed away told him to change the filter he didn't believe him until he took the orange filter off and replaced with different brand problem solved!!

 

Isn’t oil filtration also a big concern here? Pretty sure almost all oil filters have a bypass. If you routinely run over that pressure level, isn’t the oil not being filtered? At least a large portion of it? I feel like I ran into this a lot over the years with LS builds. The 2005+ motors have the “drive on demand” oil pumps that put out more volume. When you remove the “drive on demand” system and install a standard camshaft, the oil pressure sky rockets. I’d see 60-70psi at idle, and bury a 120psi gauge at rpm. I simply cut 2 rungs off the pump pressure spring these days. Keep pressure back in the “normal” range. I feel like before doing this I’d see premature wearing of the bearings due to lots of unfiltered oil going through them.

Some of the LS pans and filter housings also had bypasses. I blocked these off.

 

Isn’t oil filtration also a big concern here? Pretty sure almost all oil filters have a bypass. If you routinely run over that pressure level, isn’t the oil not being filtered? At least a large portion of it?

No there has to be pressure drop across the filter for it to bypass.
This means a dirty filter or trying to flow more oil than the filter is rated for, most engines have a filter rated for a lot more flow than the pump can deliver.

If you really needed a filter your engine is eating it self.
For the people who cut their filters you know if you find anything you are in trouble

 

Only using oil filters that don't have an internal bypass valve is the answer to unfiltered oil, and changing that filter regularly.

 

Do we have a list of commonly available filters with no bypass? I thought almost all of them had a bypass these days.

 

I just run Wix filters only, I have a plug for the oil bypass (LS engine) that I'm gonna install this winter for good measure.

 

Even if oyu plug that though, youwill stilllikely trip the bypoass in the filter. Which is annoying IMO. Cold starts generally aren't filtering the oil. I'd like to ditch the bypass 100%.

 

For LS applications, the Wix 51522XP filter states it has no bypass valve.
Think I'll try one when I change the oil and plug the bypass.

 

For LS applications the Wix 51522XP filter states it has no bypass valve.
Think I'll toss one of those on when I change the oil and do the bypass.

 

Thats def one of them. its the 13/16 16 thread though. The aftermarket pans usually all use the m22 1.5 thread. I wasn't seeing any of those without the bypass

 

Can’t you pull the nipple out and replace with the proper thread pitch?

 

Its pretty normal IMO to see a bit of glitter at the oil change when dealing with big power SBE setups. I also filter my turbo feeds. I noticed the excessively high oil pressures caused by the DOD pumps causes the bypass to trip as I’d see bits of material in my pre turbo fiters. If I get 2-3 seasons out of a $500 motor I consider myself lucky, but I don’t want my turbos sucking up garbage. When I ran the factory oil pans with the 13/16 16 filters without the bypass, I didn’t see material at my turbo screens. Bearings also looked better. I haven’t found an m22 1.5 filter without a bypass yet.

So I’ve been clipping the pressure relief spring to get pressure back down to normal. Unfortunately, I am still seeing some material being bypassed. So i'd like a filter without a bypass in it.

 

Its pretty normal IMO to see a bit of glitter at the oil change when dealing with big power SBE setups. I also filter my turbo feeds. I noticed the excessively high oil pressures caused by the DOD pumps causes the bypass to trip as I’d see bits of material in my pre turbo fiters. If I get 2-3 seasons out of a $500 motor I consider myself lucky, but I don’t want my turbos sucking up garbage. When I ran the factory oil pans with the 13/16 16 filters without the bypass, I didn’t see material at my turbo screens. Bearings also looked better. I haven’t found an m22 1.5 filter without a bypass yet.

So I’ve been clipping the pressure relief spring to get pressure back down to normal. Unfortunately, I am still seeing some material being bypassed. So i'd like a filter without a bypass in it.

Wouldn't it make sense to change the pump to Gen3, non DOD, low pressure pump?

 

Most filters with an internal bypass valve only need a 11-12 psi pressure differential across the filter for the bypass to open - so cold starts and high rpm (with the usually far too small cannister filters) will open the bypass every time.
We use non bypass filters on some of our transmission builds- to catch any contaminants left in the converter or oil cooler after a previous trans failure when customers don't want to change them for new. Our testing showed us that the bypass valve filters do allow contaminants back into the new transmission.
We typically use a remote filter housing with 3/4 -16 nipple and a Fram PH4825 non bypass filter (or equivalent make of your choice as the Fram one is not available anymore).
A better filter for race use on a remote set up is the Wix 51268R, it has a 1-1/8 nipple and flows over 30gpm - three times what most cannister filters flow. It is a race filter though , it doesn't filter very low micron particles so oil needs to be changed regularly.

 

Its a simple relationship between the amount of oil your pump flows and the amount of restriction to that flow. The only reason to run a HV oil pump is if you have less restriction to flow (large bearing clearances or things like large piston oilers or large spring oilers.

If you are seeing that much oil pressure due to tight bearings and thick oil viscosity you are reducing the amount of oil through the bearings and this will increase dramatically the temps seen in the wedge of oil seen in the bearing. In addition you will likely be bypassing the filter and pumping dirty oil through the engine.

Experiment with a different filter to make sure a bad filter is not the culprit (with the clearances you mentioned I doubt that is the issue) and if that does not drop it go to a lower viscosity oil as long as your lifters (if hydraulic) do not complain.

 

@ForceFed86

I haven't experienced that. I shim the stock spring about .100" and I drop 8-10 psi over a 1/4 mile pass. Peaks at 78 and drops to 69-71.

I have battled with stock pans and oil level causing oil pressure issues.

Regarding the OP's original question, I can't see the reason for 90-100psi of oil pressure in a factory LS block. If I'm staying over 55-60psi over 6000 rpm's then I don't believe there will be any issues caused by a lack of oil pressure. My local machine shop has put me in that direction as well.

 

Don't believe it shows up as a giant dip in pressure on the gauge.. The GPM/flow is what drops off at higher rpm and it cavitates. Leaving air bubbles/froth in the oil its supplying. I never saw it as a huge pressure drop at rpm. But I did notice it bouncing around a lot in the logs at RPM making a jagged instead of a smooth pressure line. I took that as air getting in the system as I don't see it with the DOD pumps. They have wider vanes and push more volume at like pressure.

Also heard dimpling the vanes helps to alleviate the aeration at higher rpm.

Could all be my imagination and internet bandwagon bs. But made sense to me looking at my logs. Def have no proof of this. Tons of folks have been way quicker than me on a gen3 pump.

 

Have you got any more info on the dimpled pump gears- where you had the info from etc? Thanks.

 

The question is what did the bearings look like when you changed them out? Were you using the same pump and oil weight with those bearings? If the bearings looked good then keep running it the same.

 

My gauge is on 80psi, if I drain the oil should it read 0???

 

Your oil pressure gauge reads 80 with the engine off?

 

I drained the oil and started it and it still read 80lbs

 

I also tried to just replace the oil filter and no different

 

Guess what your oil bypass spring is rated at???? 80 psi. Let the oil warm up and see what it drops to when hot....after you put the oil back in the motor.

 

It stays at 80 even after I drove from Boise Idaho to Ontario Oregon and back