I have a built motor. I'm using Mobil 1 EP 10w-30.

Idle pressure is 50-55
Any throttle input and its pinned at 100.

 

im using dominator 15w 50 with a built 2.1. cruising at 70 oil pressure is at 100. higher rpms rises to like 134. atleast thts what my defi gauge is reading. I also have the Balance Shaft removed

 

anyone have pictures of the porting done to the pressure relief?

 

I do agree with you but I will say my car has actually snapped a rocker right in half too and could only point to a missed shift and had no other explanation at the time so this seems like a second option it could be. It was like a week or two after I bought the car and it sounded Identical to an exhaust leak so I drove it around for a month till I got around to getting gaskets etc. Finally pulled the VC and found the #1 cyl exh rocker laying next to one of my head studs. I got pics if youre interested of the whole teardown and I think some of the broken rocker. and found the other smaller piece in the oil pan.

 

This

 

You can find it on DSM forums. The front case is the same. Basically just enlarge the hole without uncovering the part of the piston that seals the oil passage, or it will leak pressure when it's not supposed to.

 

Gotcha, what about shortening the spring? I've also read about that but without a lot of detail.

 

That's something you'll have to expirement with. I think @Dallas J came up with a different spring to use.

 

Also, I don't see the lack of an oil cooler causing higher oil pressure. The effect should be the other way around.

 

Yeah this was a general question. Not really related to the oil cooler.

 

My 1992 DSM handbook included a warning advising the use of a high quality oil filter in order to avoid bursting the oil filter cannister. It didn't say anything about breaking rockers. So, I'm sceptical about that. If it was a problem I think it would be fixed by the time the Evo 8 came along.

Doing the extra pumping is robbing HP. What else is bad about high oil pressure?

 

The high oil pressure means there is less oil in the pan, where it belongs to prevent starvation. The system is designed to run balance shafts, when you don't run balance shafts, those 3 or 4 ports get blocked off and pressure goes up past where it should be. Porting the bypass helps with this.


Higher oil pressure also makes more heat.

 

That makes sense. There's even talk of high delivery fuel systems making the fuel in the tank hot.

 

Higher pressure means less flow.

Less flow means there's more in the pan, not less?

 

Not necessarily. The pump is spinning the same RPM, but you have blocked off ports that supplied oil to bearing that are no longer there. And the oil pressure relief port doesn't flow enough to relieve the excess pressure. When you port the relief valve, pressure typically goes down. That tells me the pump is capable of forcing the "extra" oil to the rest of the system, and it is in fact not staying in the pan. This is why English racing makes an oil pump gear that slows the pump down. And Kiggly makes an HLA that returns oil to the pan.


Similar to turning the boost up on the stock turbo. More boost doesn't mean less flow, or the car wouldn't make more power...