455GTO

iTrader: (18)

Can you elaborate as to how the pickup would be so low in the pan? I understand there are small variances from motor to motor but what would cause such a low sitting pickup?

RockinWs6

I think this is very good possibility. Sure fits the circumstances.

RockinWs6

I never heard a engine that was not getting oil up top that was quiet EVER. I've worked on 100's of engines new used and rebuilt.

Old Geezer

iTrader: (3)

As for the correct oring.. Melling's instructions include pics of what o'ring goes w/ what tube. Not much to guess about.................If you read the instructions, that is.

G Atsma

Waaaaaaitaminute! You mean the instructions are actually supposed to be READ???? Who knew.... lol

01ssreda4

iTrader: (96)

Very simple mistake. Front of sump 5.5" deep, rear of sump 5" deep. Moved the pickup from front to rear you lose 1/2" pickup to pan clearance. What was stock pickup clearance? I dunno but i bet it was 1/2" or less. It was builder error. Sump was moved 4.5" rearward, the distance between the main caps.



Here's the damage it caused: All other rod bearings showed signs of oil starvation also.




None may have been the wrong word. Very little may have been more accurate.

timharber

Not knocking the OP in anyway but are you sure the weld job on the oil pick up tube is not sucking in air?

What viscosity oil did you use and did you use break in oil at all?

Tim

Mart00SS

iTrader: (19)

The OP is not the one who posted the picture about the pickup tube modification, it was another member sharing his similar experience and about pickup to pan clearance.

01ssreda4

iTrader: (96)

Considering i made my living as a certified welder for years Im confident it did not leak. Not tooting my own horn, it just isnt difficult for a competent welder to seal two pipes of the same size/material with a decent fitting joint.

timharber

Sorry i din't realize it wasn't the OP pick up tube. It was just a suggestion, not a knock. Sometimes the most obvious things escape us when we beat our heads into a block wall over and over again. If there is the slightest little air hole in the welds or the tube is bowed, it could cause issues. Sorry if I offended you, it was not my intent at all.


Tim

I R Gunnr

I dropped the assembled engine at the machine shop and haven't picked it up yet. They couldn't find anything that they thought would allow air in. I ordered a new pickup and bought a ported LS6 pump as insurance. I hope to find the problem once I pickup my short block and all my old parts.

Outside of a cracked pickup, my working theories are I distorted the oil pickup tube end either out of round or used an o-ring that was too big. Maybe when I went back to the factory o-ring, it couldn't make an air tight seal.

This has happened twice though, same symptoms, ticking oil pressure gauge, top end noise, and absolutely wrecked bearing. I blamed the machine shop the first time thinking they didn't clean up after machining, since the all the plugs were still in. I used a different machine shop the second time, with all CNC machines, very reputable etc. Same result.

Oil was 10w-30 Driven Racing oil, the Joe Gibbs racing stuff.

I R Gunnr

Please sanity check me on this, the air HAS to be getting in downstream of the pump right?

My oil cooler lines were leaking, but if the lines have 40+ PSI on them I can't see the oil flowing fast enough to create a venturi effect and suck air in.

A.R. Shale Targa

iTrader: (2)

Bad gasket on the back of the cam retention plate ??

01ssreda4

iTrader: (96)

Nah I didn't take it that way. We know the pump creates suction to draw oil up. If it had a pinhole, it would introduce some air. It is feeding an entire engine and will take the point of least resistance to do that, whether suction or pressure. It's suction up to the impeller, and pressure after. A pinhole leak wouldn't introduce enough air to cause an issue, meaning it would not reduce suction on the oil, therfore the amount of air to oil ratio is still highly favorable. Where this applies to me and the OP is the pressure side. Bearings and lifters are fixed leaks. The system is designed to feed all of these leaks and still have adequate pressure after all leaks are accounted for. The issue is all leaks aren't fed at the same time, so if an earlier one is excessive, the ones following it suffer with lower pressure. Or, in my case, the cavitation (at the very beginning of the process) caused enough of an issue that i was starving bearings but still getting pressure to the sending unit and showing pressure on the gauge. So it was making the system work halfway. The problem is the rod bearings are last to get fed and there wasnt enough good non-aerated oil left to properly feed them. If bearings are being starved, the entire oiling system from the pan, the suction, the pressure, all the way to the top of the engine must be examined, in order, in my opinion.

A.R. Shale Targa

iTrader: (2)

Well said sir ^^^^^^^^^^^^^^^

RockinWs6

The real problem is the pressure sensor doesn't know if it is reading oil pressure or air pressure. So 70 psi reading on the gauge could mean anything from all oil or half air. I'll tell you what you could try is pull the spark plugs crank the engine until you have pressure on the gauge so you know the bearings have oil. The pull the oil filter off then use a clear container to collect oil from the oil filter inlet. Crank the engine and see if it pumps out clear into the container, It should. I would do all this before installing the engine, you need to find your gremlin before it costs you anything more.

You could do this with the heads off, good way to play with it without running the engine. Thing is some air in the oil won't hurt anything as long as the engine is run low rpm no load. But putting any load on the engine with air bubbles in the oil will cause wear. The only place air can enter is on the suction side of the pump, once the oil is under pressure it is above atmosphere and air can not enter because it is lower pressure than the oil.

I R Gunnr

Excellent idea, thank you! I built a setup to run a mechanic oil pressure gauge on the motor and my sending unit simultaneously. I'm gonna pull my starter off put it on the block once I'm all assembled and prime, then run the starter to get oil pressure all while on the engine stand. The clear jar at the oil filter neck is awesome, should be able to crank this engine with confidence now. The only variable I can't include is the oil cooler, but being it's downstream of the pump, I can't see it being the issue.

computerz

+1 vote for high volume pump sucking all of the oil out of the pan. Check out the picture of bearings here (not mine):

https://ls1tech.com/forums/forced-in...l#post19594989

RockinWs6

I agree, this time he has to cover all bases or pay the consequences. Sometimes its not so easy to solve a simple problem like this because you can't find anything obviously wrong BUT the gauge ticking 5psi all the time is a dead giveaway something is way wrong.

computerz

yeah, i wonder if the pump sucks all the oil until it's just air (gauge drops), enough oil returns to the pan so it gets oil again (gauge increases)... repeat...

agreed, it could be different reasons. OP mentioned a HV oil pump, so that's a possibility given others experiences with them.