Built motor oil

[ZeroGravity58]

What is everyone running in their 1000hp+ motors? When is it worth it to step up to a straight weight oil? I currently run amsoil dominator 20w-50. Forged pistons, hx bearings. After a couple hard pulls oil pressure is lower then I like even with DHD oil pump. Just looking to see what others opinions are.

 

[gmduramax]

Ran rotella 15/40 conventional. Would change it every 5k, sooner depending how many passes I put on it. Stock oil pump.
I have about 135k on HX bearings.
I wanna say 20ish psi at idle 77psi WOT

 

[ZeroGravity58]

I only have about 2k miles on my built motor. At idle I have around 15psi and 60+ at WOT that's logging it with efi. I do run twins and a couple hard runs my oil temps will get up. Normal driving or cruising around 210-220, WOT pulls they will see north of 240-250

 

[Chevy1925]

God damn that’s hot.

I’d switch to a 15w40. Thicker doesn’t always mean better, specially with a higher volume pump. Thicker will heat up faster and run hotter due to the viscosity. Even with HX bearings, I’d run 15w40 and not worry.

 

[ZeroGravity58]

That's what I was unsure of, go to thicker oil or thinner oil. I think the oil temp is a combination of things. I ran a stock lbz oil cooler, twins are 366/488 so the oil is sucking up a good amount of heat. My oil temp sensor is in the oil filter housing. If I cruise down the road at 80mph I'll see oil temps of 220-230 depending on the weather

 

[johnmyster]

It sounds like oil cooling is the issue. Is an L5P cooler an option? I'm not 1000 hp, but towing, I slow down when oil pressure begins to fade on grades.

 

[ZeroGravity58]

It is, I shoulda went with a lp5 cooler or maybe it would be different if I used a Garrett based charger that is water cooled. I was thinking if maybe a different oil would help it some. I also don't tow at all with this truck it's strictly a fun truck but I do take it on long trips

 

[johnmyster]

Your turbos are putting heat into the oil but so are eight pistons. At high power, isn't trivial.

More viscous oil at temperature would help keep pressure up, but so would keeping the oil cool. Higher grade oil is a cover up. Temperature is the problem.

Early L5p oil cooler is 65% more plate area. Late L5p cooler is 100% more plate area.

 

[PureHybrid]

Is the temp sensor pre cooler? 250F coming from the pan isn't extreme IMO. Not sure what Amsoil charges for the dominator oil, but I'd opt for something cheaper and change it more often. Lucas Magnum HD isn't too expensive, has higher ZDDP than newer CK oils.

 

[Bdsankey]

It is, I shoulda went with a lp5 cooler or maybe it would be different if I used a Garrett based charger that is water cooled. I was thinking if maybe a different oil would help it some. I also don't tow at all with this truck it's strictly a fun truck but I do take it on long trips

It's not too hard to swap coolers. With the larger cooling stack of a 06+ truck the 2020 cooler really doesn't have any downsides. As for oil we tend to stick to CenPeCo or Hot Shot's. CenPeCo super-race or S3 is what I used to run in everything and had zero bearing issues. I've switched to Hot Shot's recently and have had the same results.

Your turbos are putting heat into the oil but so are eight pistons. At high power, isn't trivial.

More viscous oil at temperature would help keep pressure up, but so would keeping the oil cool. Higher grade oil is a cover up. Temperature is the problem.

Early L5p oil cooler is 65% more plate area. Late L5p cooler is 100% more plate area.

Forged pistons do not put the same heat load into the oil that a cast piston does since they do not have the oil cooling pockets.

 

[ZeroGravity58]

Maybe I'll look into swapping oil coolers. It would be a lot easier on the stand . I'm taking temps precooler from the top of the oil filter housing

 

[1FastBrick]

Best of luck finding one right now... They seem to be on back order. I don't know if GM made a change again or what but for some reason they seem to be back ordered.

 

[johnmyster]

Forged pistons do not put the same heat load into the oil that a cast piston does since they do not have the oil cooling pockets.

Brad, thanks for enlightening. I assume forged pistons are safe to run hotter than OE, and thus, do a greater percentage of their heat rejection back into the combustion chamber?

Or, do changes in geometry (de lipping, reducing surface area) help them to not pick up as much heat in the first place?

 

[Chevy1925]

Best of luck finding one right now... They seem to be on back order. I don't know if GM made a change again or what but for some reason they seem to be back ordered.

The strike a while back did it. Tcm’s are back to being hard to get

 

[NC-smokinlmm]

I’m running the VR1 racing oil in my stroker, it’s got a bunch of zinc in it. I’m not sure if it’s ok for a diesel though. I’d look into it if your wanting a really good motor oil.

 

[PureHybrid]

I’m running the VR1 racing oil in my stroker, it’s got a bunch of zinc in it. I’m not sure if it’s ok for a diesel though. I’d look into it if your wanting a really good motor oil.

They changed the "zinc" levels within the past year or so. Overall it's lower but they increased levels of a few other important additives, vr1 is definitely a great oil. Local parts guy used to get Brad Penn for less than vr1 was sold at most retailers, not so much anymore. I think Valvoline sells the Vr1 dirt cheap on purpose to undercut the niche market oils. BP was a huge success for guys running alcohol and vr1 kind of struggled in that area, but that was 15+yrs ago

 

[Bdsankey]

Brad, thanks for enlightening. I assume forged pistons are safe to run hotter than OE, and thus, do a greater percentage of their heat rejection back into the combustion chamber?

Or, do changes in geometry (de lipping, reducing surface area) help them to not pick up as much heat in the first place?

It's a bit of both. The material used has a higher melting point. Also due to the lack of an oil chamber in the piston (best term I can come up with right now) they have more thermal mass and thus don't heat up as quickly.

Plus they usually have very generous radii on all cuts and bowl designs to help eliminate any hot spots.

The greatest heat transfer is through the piston itself. This means they do a great job of moving heat away from the surface and back into things like the cylinder walls and oil.