My friend recent suggested the cam retainer plate / seal to be the source of the issue.... wouldn't that cause issues with oil to lifters and such? Would have severe valve train noise? Engine sounds cherry... no clattering of any kind.

The rear oil galley plug would also prevent a good flow of oil to the oil cooler as that sits inline from the egress port on the oil filter going up to the oil sending port / top of engine.

We have used multiple Mobil1 filters.. I've never had any issues with them before, but we are swapping to a WIX filter to ensure the M-107 style filter is not the cause of issue.

We are gonna pull the engine regardless - we will pull off the pan as we disassemble the engine and investigate for anything blocking the pick up tube and stuff.

 

The cam plate leak would drop pressure at the top end but as long as you had 10lbs there shouldn't be an oil starvation issue. The schematic shows the sending unit feeding off of the back of that oil galley.

I thought you might be able to see something by just removing the lower oil pan, if there was an obstruction, without having to remove the engine.

 

Sorry to here you got big problems . If there is a next time buy from GM Jags Summit and a few more sell REAL GM long blocks and motors and when you buy one you get to call GM and they will tell what you need for the install and if you got problems will help with it . The LS motors are easy to work on and to build also if a person can't get a LS motor right ,way not a motor builder .. I build my LS-6 with a internet video .. Runs good.. 550HP . Got to do your home work ..

 

SOMETHING DOES NOT LIKE anything above 55 PSI. And when it starts leaking, it keeps leaking till the pressure goes low again..

The Guy that sells the billet barbell plug knows a LOT about the purpose of that plug and what effects it has when it doesn't work correctly. I looked for his post and could not find it.

I would call/email him and get some more details!!


Take a look at this post:

http://ls1tech.com/forums/generation...-oil-plug.html

There are more than one oil port plug.

On the oil filter housing there are some seals that can fail under pressure and bypass pressure. I would check that before you pull the engine.

 

Bill,

It isn't PSI related - it is RPM related.

With the Meiling pump and lower weight oil 30w, my max PSI was 36 before dropping to 30.

With TSP pump and 40w oil. it is about 50 tops down to 40 when oil is HOT.

I apologize I do not have a video of the meiling pump doing the same thing but at lower pressures.

 

This is the response I received, I do not believe this contains any private information or is considered to confidential as it relates to the simple operation of the engine. Mods - please delete the post if I am not allowed to quote verbatim form my builder.

--My thoughts--
I do not believe this is normal operation of an engine, if anyone has an LS based engine that does similar and runs without issue, please message me.

Is it possible I request him to sign a document stating it is advisable to ignore the possible issue and if there are any problems down the road he will cover it? (If any issues arise from oil starvation or problems with the oiling system over the next XX miles, Builder will cover all costs?)

I think it sounds stupid to even think of that... but it feels like they just said "yup don't worry about it, or try this other solution" - why didn't they even suggest this in the beginning? Just a redirect.. more money.. I personally have read of LS3 folk going to the LS1 batwing pan to help with oil starvation issues... I can't be the only one with a 427 LS3 with batwing pan.

What should I do?

---QUOTE FROM BUILDER: (in email)
"I have spoken with our engine builder and outside sources for additional feedback. We are of the opinion that what you're seeing is not a concern. The new block, rods, pistons, and bearings met all specifications and clearances.

I believe that you're seeing one or two things happen in the engine.
1) The oil pressure relief valve in the oil pump opening up. The are set to start opening at 33psi where some other pump valves open at 40psi. Oil pressure should be rolling off at 50psi in all LS based engines with stock type pump. I have attached two documents that support this opinion for your reference.

2) I believe you are using a C5 "Batwing" oil pan in the car. The use of a long stroke crankshaft requires the oil pickup tube to be shimmed down. This narrows the gap between the bottom of the pickup tube and the oil pan floor. If proper gap is not maintained, you will see oil pressure roll off as the pump cannot pickup enough oil. This causes a starvation. Many past C5 customers have moved to a C6 LS2 oil pan for this reason. It has a deeper sump allows for better oil pickup tube fitment.

At this time, I do not see a reason to worry about the oil pressure. I suggest that you monitor it and note any changes in pressure or behavior."

 

How much are you asking?

 

hmm, I have a LS1 engine with the LS3 oil pan and the GM High Volume oil pump, my pressure is always max at any RPMs

 

I looked at your video several times and it seems that the oil pressure doesn't fall off till about 55 lbs. Does the pressure fall off it you run it up to say 50 psi and hold it there? It sure does look like the relief ball is opening. While I don't have any experience with the ls series engines, I've seen this problem with the gen 1 sbc. One problem I had years ago was I had the pickup TOO close the the pan and it starved for oil, but was unlike yours. Your oil pressure flutters like it's bouncing the check ball on the spring.

I'd run it til about 48 psi and hold it there, to see if it falls off or stays steady.

 

I wish I had the video of the same thing occuring with the other pump... yet only reaching 36lbs max, then dropping down to 30.

AFAIK its RPM related. not pressure. Wouldn't the cold pressure be affected in the same way?

 

Don't compare one pump to the other, even exact pumps could have a different running pressure.

It will seem rpm related because the more rpm the more pressure. If it moves the ball off the seat at a certain pressure it will stay off the seat until the pressure reduces enough to seat the ball again. Just try and set the rpm til you have 48 psi and see if it will sustain that pressure. Have you checked to be sure the bypass plug is installed? My brother and one of his friends put a 406 sbc together a few years ago and didn't put the bypass plug in it. That engine didn't last too long, until it spun the bearings. I fixed it and ran it for a few years, shifting at 7000 rpm. That engine had at least 450 1/8 mile passes when I sold the car.

Cold it should be worse, but you won't see the drop as quick. About the only thing that can cause what you're seeing is, check valve or aeration of the oil before the pump. It looks like to me it's building good pressure til it blows the valve off the seat. If you do back to back revs does it build the 55 psi before it drops again?

 

Id park it, save some money, and give it another go in a few months.

 

I still have a feeling you can get this worked out without pulling the engine and spending much money.

Your car is awesome. Keep trouble shooting. If two minor problems exist by chance it can make things confusing.

 

Does the bottom come off your pan? There were one and two piece versions.
If it's a two piece, it's easy to check the pickup to pan clearance.

Too close can be a problem.

The way the gauge jumps, seems like air in the system. Although I know you have done multiple O-ring replacements.

There is a pressure port in the side of the block under the alternator. Have you checked it there?

Lastly, have you tried it w/o the oil cooler?

barbell missing gives little to no oil pressure btw.

Ron

 

We will do some testing - it seems to me once the oil pressure drops enough (2k rpm or something) then will build normally again.


Thanks. We are looking at all possible options currently

We haven't checked the pressure port in the side of the block yet.. we can do that.

 

HI GUYS..Had a low oil press prob with a 6 litre. used eng..pan had been removed for inspection and when replaced the pan gallery seals were not installed properly..It may have been mentioned before. but it is an easy?? and cheap fix if pan gasket seals found misplaced or damaged. and it would initially not prime the oil system on start up, due to blowing oil into the pan and not into the proper gallery. Just a thought...CHEERS TERRY

 

I am not aware of pan galley seals I'll start researching. We are pulling bottom part to check oil pickup tube clearance currently.

 

What an awesome forum. A member puts the call out that he is throwing in the towel, and numerous others respond with encouragement and advice.
derz - I don't know beans about engine internals, but when you get a gang like this rooting for you it sure makes the struggle a little easier.

Best wishes on chasing down the cause and cheers to a great group of Vette-brothers.

 

Sam, You are right - a bunch of good dudes here. Gave me the energy to keep trying.

Checking pickup tube clearance now, swapping oil filter & new oil, then checking pressure at pressure port behind alternator.

If issue is present at front pressure port, it is coming from the pump/pickup.
If not present, could be something with the bearings or further down the oil circuit?
Currently testing from the oil pressure sending port.

 

^His car is bad ***.