T-Bones Goat

iTrader: (3)

We've been doing a Warhawk build and we are having low oil pressure issues as the motor warns up. It will start out at around 48psi but by the time the oil temp gets to 115 it drops to 16psi at idle. The hotter the worse it is. I have had the engine in and out three times, checking clearances and even switching blocks with no luck. We have a ls4 oil pump in it and have checked the oring and even tried a different pump. A friend mentioned that we check the lifters. I am running a set of solid morels that are new but 5 years old. The cam is a 750 lift. At this point we are at a complete loss as to what the problem is. Has anyone heard of any problems with the solid lift tie bar lifters from years past that may be causing oil pressure loss? Thanks for any thoughts.

GTO1_OHIO

iTrader: (3)

I had the same problem with my ERL 427 block ( I have a 650 lift). ERL took the block back tightened the clearances, plugged the DODs, heated the block to see if microcracks were opening up when the block got to temp and probably a few more things I've forgot. None of this helped. Morel's a friend of the shop that works on my car so they inspected my lifters and got involved to come up with ideas. Didn't find anything though. We tried several oil pumps ... SLP & Melling and ran 50w dino. This went on for a year. Some things helped a bit but nothing solved it... until

https://ls1tech.com/forums/generatio...-pressure.html

... we went to Katech's high volume oil pump and now can run 20w50... it's solved the problem so far.

Gray86hatch

iTrader: (83)

What is the main clearance?

I run a Schumanns pump they have a volume way higher than a Melling.

Tim

T-Bones Goat

iTrader: (3)

22-23

Gray86hatch

iTrader: (83)

That is a little loose but should not be that big of a deal. I would want it .018-.020

What is a bore dimension of the mains. Did it get alighn honed to gain main clearance. On alum block the bore is going to get bigger with heat and if the bore is on the edge of being a little to big to begin with the heat will only make it worse.
This is what happened to my engine the first time. That and the mains got set at .028. It didn't last long.

Tim

T-Bones Goat

iTrader: (3)

Thanks. I just don't think the pump is the issue since we tried two different ones with the same results. The ls4 pump is what they run in the ls9 motor. Ddixon has it in his Warhawk built by the same builder and its working great. His is a hydraulic lift motor though. I am at a complete loss at this point. The first time I put the motor in, I tried vr1 20/50 to see if it would solve the issue. It helped a little but not enough. The motor i had last year had ~45 at idle hot. This one is nearly identicle to what yours was.

T-Bones Goat

iTrader: (3)

He set them there since it is fi motor. This same builder has done other Warhawk builds with no issues. The last one he built for me would hold 45 at idle hot.

T-Bones Goat

iTrader: (3)

It does sound like a clearance issue but he is 100% confident that's not it. Also keep in mind that this motor should be in excess of 1100rwhp.

Gray86hatch

iTrader: (83)

You need a better oil pump.

Contact Tim at the Car Shop Inc he sells Schumanns line and can get the one you need.

Tim

T-Bones Goat

iTrader: (3)

Im just skepticle about the pump being the issue. The reason being that I put the same pump that made 45psi hot in the last warhawk I had (I broke a rod in it last year and daylighted the block)and it actually got a little worse. The main change I have made is going to a solid setup and larger cam on this motor. I really appreciate everyones thoughts. I am at the point of daylighting this motor with a .50 cal.

Old Geezer

iTrader: (3)

No Warhawk "whiskers" here, but a "what if" ??...

Adding more lift on the cam, obviously raises the lifter further. Might the lifter body, [being it's a solid] have the body wt reduced by machining, so much so, that the added lift is uncovering the oil port in the block? It wouldn't take much, as the cold oil would have a lower volume pushed thru the leak, vs hot oil. Thus the 48psi vs <16????

T-Bones Goat

iTrader: (3)

I think this may be exactly what is happening. My builder is going to make few calls tomorrow but it seems this may be the last piece of the puzzle. Thanks