Forcefed86

iTrader: (4)

Recently put together an 08 alum 5.3. I removed the DOD lifters and blocked off the DOD ports. Engine had around 100k and Is pretty much stock. I'm seeing 55-60psi on cold starts 45ish at 1000rpm idle warm. 80+ (pegs my mechanical gauge) at 5k+ WOT.

Anyone putting in lighter relief valve springs with these DOD oil pumps? Seems like I'm losing a ton of power running excessive oil pressures. Wouldn't mind dropping it down a bit. I've got a few gen 3 oil pumps laying around. Anyone know if dropping in a gen3 spring will drop pressure considerably?

running 5w30 oil now. Was thinking of dropping to 0w20 oil.

Suggestions?

Prorac1

iTrader: (4)

I cant completely answer your question, however, I have an 08 LY6 with the DOD ports plugged and have the same oil pressure as you. I run 10w30 regular oil. Its a N/A carbed build. Eric L

Forcefed86

iTrader: (4)

Do you have the actual highest reading at WOT? Does it go much over 80?

Thanks!

Mine is a little turbo setup, but nothing fancy.

1989GTA

I have an L92 with VVT and my readings are close to yours. Does you motor have VVT? If it does, it comes from the factory with a higher rated oil pump. The motor uses the higher pressure oil to move the camshaft around. So perfectly normal.

Forcefed86

iTrader: (4)

No, mine did not come with VVT, but I do think it got the beefed up oil pump. My gen3 motors never had pressure like this even shimmed a bit. I'm not really worried about it breaking anything, but i see no reason for the higher pressures for my uses. It just robs power.

1989GTA

You can go ahead and put the standard pump in it.

COSPEED2

iTrader: (7)

I would def put a reg pump on it. I have seen so many phantom problems due to not changing the oil pump to a reg one. And by reg i mean switching from the vane type to the georotor pump, like any of the melling 10295/10296 or the LS6 pump.

Gray86hatch

iTrader: (83)

You will be fine. Changing the pump is waisting money. You might gain 5-10 hp at the most.

My dad's car makes that kind of oil pressure has 20,000 miles on it with no issues. My car makes more than that with no issues.

Kurt Urban runs them that high had he has been building these engines longer than anyone.

Tim

COSPEED2

iTrader: (7)

Its not the pressure I am concerned with totally, altough it is high. Kurt Urban would likely not recommend running that much pressure on the street esp with stock bearing tolerances etc. The vane type pumps do not ONLY put out more pressure etc.

Gray86hatch

iTrader: (83)

The extra volume is not a issue either. I have the same hv pump in mine with other mods to increase the volume above that.
Kurt and I have talked and alum block engines can't get big on the mains or you have problems that pressure and volume won't fix. Been there tried it.

Tim

A.R. Shale Targa

iTrader: (2)

People with higher oil pressures and turbos end up putting restrictors in the turbo feed line to prevent blowing past the bearing seals and injesting oil which inherently invites detonation and BOOM for high boost/hyper piston applications.

COSPEED2

iTrader: (7)

With all the reported problems of so many LS engines having blowby/pcv/oil consumption issues, i am surprised you would want to add more oil to the mix.

Gray86hatch

iTrader: (83)

Those issues have nothing to do with higher oil pressure.

Dads car doesn't use oil on a 4000 mile oil change.

Tim

Forcefed86

iTrader: (4)

Good to know... I'm not too concerned w/ damage, but every little bit helps with power loss I'd have to pull the motor to change the pump, so that won't happen. But I can get to the relief valve and figured I could dike off 1-2 spring coils or put in a lighter spring. Do you know if kurts run thinner oils? 0w20 for example?

Thanks!

Forcefed86

iTrader: (4)

Swapped cam so I had to pull the pump anyway. FYI 2 coils off the spring still has me slightly above “normal” pressures IMO. Seeing about 60 cruise at 2k. 35-40 at 1000 rpm idle. High about 80 wot at 6500. 5-30 autozone synthetic.

Oil pump is not port matched or anything.

COSPEED2

iTrader: (7)

Why run such a poor quality oil?
I would not mess with the spring. The pressure isnt a problem any extra volume may be though sometimes. If you use a thinner oil you may likely see lower pressure as well.

On a cold start (which is what I imagine the 1k rpm idle is) you should see higher than that. I have a truck with 200k miles on it and it has 40-45 at idle (650 rpm). I would not have messed with the spring at all.

Gray86hatch

iTrader: (83)

There is nothing wrong with those pressures. Mine makes 10-15 more than that.

Tim

Forcefed86

iTrader: (4)

Thanks for the input. Like I said above I wasn't worried my motor was going to implode or anything at those pressures.

I run a $500 engine that I removed the GM DOD option on. The oil pressure was excessive in my case. From what I've read there is no benefit to running excessive oil pressure. It wears out your pump more quickly, and robs additional power to create higher pressure.

In my application what I did was beneficial both in power production and pump longevity. Releasing tension on the spring by cutting a few coils hurts nothing. 10psi for evey 1000rpm is the standard, and a perfectly OK pressure range IMO.

Nascar runs 50psi at 9000 rpm and around 20psi during qualifying for the added power. Now I know I'm not driving a nascar, but to say my junker needs 90+ at a blistering 6500rpm seems crazy.

Also there is nothing poor about the quality of the oil I’m using. It meets/ exceeds the GM requirements and is the suggested GM weight. Buying into expensive oil theories is a giant load of crap. Money is better spent elsewhere IMO. Especially when your running a $500 engine.

(the 35-40psi was a fully warm idle)

COSPEED2

iTrader: (7)

I dont buy into theories nor do I run synthetic. I use regular dino and my wallet and vehicles are happy.
The quality of the base stock oil will change by huge degrees.
If you want a better idea on oil bobistheoilguy's forum has everything you could ever think of in regards to that.

NASCAR engines arent $500 jy engines either. Nor can you buy their oil over the counter.

Forcefed86

iTrader: (4)

No, but the same theory applies. The engine has to work harder to make higher pressures. If the higher pressures aren't needed, then that is wasted power. Personally I don't believe I need more than 10psi per 1000rpm in my motor. If you do... more power to you.