125psi oil pressure
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Teching In
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125psi oil pressure Hey guys, I know this has been beaten into the dirt on here but I have a specific situation. Long story short I've just gotten my street/procharged 430ci sleeved LS up and running. Engine is brand new with less than 300 miles on it. On my last log I just noticed that my engine oil sits at 70-80psi idle while cold, however under mid-throttle, the oil pressure slowly climbs to 90, 100, all the way to 110-125psi at just 4700rpm. This engine is still being broken in so that's as far as I took it. I don't believe it to be the oil sending unit, as the idle when hot calms down to 45 psi, but hopefully I'm wrong. I have a melling 10355 pump, is this pump even capable of 130psi? Even under mid throttle the pressure will spike to nearly 110psi. One more thing to add. Apparently my shop that installed the motor threw in 20w50 VR1. My machine shop that built the engine told me to only run 10w30, and seemed very pissed that 20w50 was used, making it seem like it's the end of the world for this engine. My fault for not double checking with my shop, however I wouldn't have expected them to use this heavy of an oil. Any internals experts willing to chime in? It's between 40-60° where I'm at now. I'm changing my oil to 10w30 asap but I'd just like to clarify if such a heavy oil has done any harm at this point. Thanks
Staging Lane
Joined: Mar 2022
Posts: 84
Likes: 41
From: Wenatchee WA
I seriously doubt any harm was done especially since have not run the engine hard. If it were me I would drain the oil, cut open the oil filter and inspect for any metal just like you normally would on a new build.
Please let us know what you find.
Thanks!
Please let us know what you find.
Thanks!
Thread Starter
Teching In
Joined: Aug 2019
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I'm definitely sending in an oil sample to Blackstone labs.
This is a quote from my machine shop: The Oil clearances on that engine and every other LS engine is pretty tight, that’s why I said use 10W-30, first thing that happens is oil cannot transfer through the crank and bearings so it won’t allow enough oil to escape the bearing and be thrown up into the piston skirt area, I hope this has not caused an issue already because it will. The higher pressure that you’re having now is because the oil is so heavy it’s being backed up in the system."
This is a quote from my machine shop: The Oil clearances on that engine and every other LS engine is pretty tight, that’s why I said use 10W-30, first thing that happens is oil cannot transfer through the crank and bearings so it won’t allow enough oil to escape the bearing and be thrown up into the piston skirt area, I hope this has not caused an issue already because it will. The higher pressure that you’re having now is because the oil is so heavy it’s being backed up in the system."
TECH Resident
Joined: Jun 2013
Posts: 814
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From: Nebraska, The Good Life
20w-50 oil in a modern engine like the LS was a big mistake. 20w-50 is fine for older engines (think 50s-60s-70s Chevy small blocks) if they are going to we wound up high and aren't built with super close tolerances, but in a close tolerance engine like an LS is a problem because as mentioned it becomes hard for the engine to push that heavy oil to the places it is needed easily and quickly.
Thread Starter
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Joined: Mar 2022
Posts: 84
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From: Wenatchee WA
for what its worth, I have ran the 10355 pump in my ls2 resleeved block, and in my dart ls next block with excellent results. drain the oil and use a qaulity 5w30 or 10w30 oil.
TECH Resident
Joined: Jun 2013
Posts: 814
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From: Nebraska, The Good Life
Big mistake meaning you could potentially have damaged engine parts such as bearings, rings, pistons, cylinder walls, cam and lifters.
Change the oil and monitor things closely moving forward. Then go slap the idiots at the shop who installed the engine.
For the parts receiving pressurized oil (bearings, lifter bores, etc.) there is likely not much of a chance for issues since the oil pressure indicated there was oil aplenty at those locations. As your engine builder said the issue would be those parts relying on splash oiling such as the piston skirts, cylinder wall, rings, rollers on the lifters. The rockers are probably fine as long as they were properly prepared on assembly.
An oil analysis will tell you if wear was excessive, but this was a fresh engine so the metal particles in the oil will be much higher than normal anyway. The trick will be to determine if they were excessively high for an engine break in. The only other way to know for sure unless there are other obvious signs, would be to tear the engine down and physically inspect things and remeasure the clearances.
Change the oil and monitor things closely moving forward. Then go slap the idiots at the shop who installed the engine.
For the parts receiving pressurized oil (bearings, lifter bores, etc.) there is likely not much of a chance for issues since the oil pressure indicated there was oil aplenty at those locations. As your engine builder said the issue would be those parts relying on splash oiling such as the piston skirts, cylinder wall, rings, rollers on the lifters. The rockers are probably fine as long as they were properly prepared on assembly.
An oil analysis will tell you if wear was excessive, but this was a fresh engine so the metal particles in the oil will be much higher than normal anyway. The trick will be to determine if they were excessively high for an engine break in. The only other way to know for sure unless there are other obvious signs, would be to tear the engine down and physically inspect things and remeasure the clearances.
If I had to wager money, I think OP has done no damage at all-YET!! But he'd better get that junk outta there. 20w-50 is more of an air cooled, high powered motorcycle engine oil, like an older Harley or Triumph/British big twins. Somebody was sure asleep at the wheel when they dumped that stuff in there. Cold flow to the mains and rods would suck. Especially in an LS engine, which, for whatever reason, the engineers deemed the lifters and cam bearings need oil before the mains and rods. 5w-30 oil would be fine, even 0w-40. My opinion.....
Thread Starter
Teching In
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One too many W's. I'm planning on using Driven BR40 for break-in on my engine. Maybe I'll do a build thread - LS based 396, Callies crank, rods, JE pistons, Kong 2650
I have a 430” Darton MID sleeved ls6 block that I had rebuilt last year, engine builder told me to run 20w50 after the breaking in oil. I use brad penn 20w50 and everything seems fine, he just told me to make sure I let the oil heat up before I go beat on it. Ive had it through a dyno tune session and one track outing and everything went great with the engine. Mine is also procharged.
Thread Starter
Teching In
Joined: Aug 2019
Posts: 11
Likes: 1
I have a 430” Darton MID sleeved ls6 block that I had rebuilt last year, engine builder told me to run 20w50 after the breaking in oil. I use brad penn 20w50 and everything seems fine, he just told me to make sure I let the oil heat up before I go beat on it. Ive had it through a dyno tune session and one track outing and everything went great with the engine. Mine is also procharged.
