Generation IV Internal Engine - Dod oil pressure relief

Can you plug the DOD oil pressure relief in the pan? I'm not running DOD and lifters are gone. I'm not for sure what needs to be done to the pressure relief. It looks like it regulates oil pressure to 55-75psi.

Since nobody seems to know anything about this I think I'm going to block it off.

Can you plug the DOD oil pressure relief in the pan? I'm not running DOD and lifters are gone. I'm not for sure what needs to be done to the pressure relief. It looks like it regulates oil pressure to 55-75psi.

It has been done successfully with a resultant increase in oil pressure. Sometimes too much sometimes only a little. Depends on the particular engine and which oil pump it has.

I'm running a Melling 10296 with stock blue spring. I'm wondering how I'm going to plug it. It has a 14mmx1.5mm threaded relief in the pan. I haven't found anything to plug it with those threads.

Why would you want to mess with plugging it? It is only a high pressure relief, and if you do not have high pressure, it will never relieve. If you do have high pressure, why would you not want it to be relieved?

Regards, John McGraw

The primary purpose of the pressure relief valve in the oil pan is with DOD/AFM engines with higher volume oil pumps to support the DOD/AFM oil usage and probably also with VVT.

With 30% higher flow in these cold start oil pressure (sub zero locations) can be through the roof and exceed the specs of the DOD/AFM solenoid valves which it appears maxes out just north of 75psi.

In non DOD/AFM engines, they may bleed some pressure off even with the stock oil pump if the engine is tight oil wise.

If you have 50psi hot and want to chase the "rule of thumb" 65psi at 6500rpm (which is way above GM specs, but then GM specs arent for racing :)), then maybe you will get there by blocking the relief off. You may also get 100psi and be driving the oil pump real hard and taking more power that is unnecessary, and possibly heat the oil up further than normal. And if the DOD/AFM solenoids are still there, well, maybe they will give up.

GM put the relief in there for a reason. If you have 55-65psi hot (like 210-220 hot), then you probably dont need to worry about any more pressure.

:)

They don't have the relief on older pans. I have a LS2 engine with a truck oil pan on it that was DOD. The pump is a melling 10296. The factory pump was high volume. The VLOM or solenoids are gone with the lifters too so I don't see why you would need it in there. The relief can open anywhere from 55psi-75psi according to the specs. I really don't see why it would matter since other engines weren't fitted with this. Just vehicles that were retro-fitted with DOD or Active Fuel Management.

They don't have the relief on older pans. I have a LS2 engine with a truck oil pan on it that was DOD. The pump is a melling 10296. The factory pump was high volume. The VLOM or solenoids are gone with the lifters too so I don't see why you would need it in there. The relief can open anywhere from 55psi-75psi according to the specs. I really don't see why it would matter since other engines weren't fitted with this. Just vehicles that were retro-fitted with DOD or Active Fuel Management.

Dead right! :)

I ran this with a different engine without dod and LS7/cam. The oil pump was also aftermarket and oil pressure would go to about 55psi and that was all. I'm thinking it was relieving pressure then. I'm going to plug it with a 14mm drain plug and gasket with red loctite on it.

Maybe I should just get a older pan off a different truck?

My point is, do you need more than 55 PSI of oil pressure? If not, then why mess with trying to plug something that causes no problem? None of my engines ever go over 55 PSI and my LS1 seldom makes over 40 PSI.


Regards, John McGraw