2G High Oil Pressure Issue

[alice]

I finished my mini rebuild a few weeks ago and have since put about 200 miles on the engine. I went with an OEM composite headgasket and ARP's which I just re-torqued to 90ft/lbs a few days ago. I also installed a Prosport electronic oil pressure gauge and left the stock oil pressure gauge installed and functional. So, I am concerned with my oil pressure now. I removed the balance shafts and installed the new bearings to block the oil ports where the balance shafts were.

At full temp idle I see about 20psi however, at cruise at a steady 3,000rpms I see a consistent 75-80psi and the stock gauge is just about pegged to the top mark of the range but not above it. This is what concerns me most, steady driving with oil pressure in the 75-80 psi range. At WOT it almost immediately hits 90psi and steadily makes its way up to to 100psi as I approach redline. I have not ported the oil filter housing as of yet. Will this high oil pressure kill anything before I get a chance to port the OFH to reduce oil pressure?

 

[BLINKY619]

did you remove the balance shafts

 

[Shadow21]

time to port your oil housing.

 

[alice]

I did remove the balance shafts and installed the new bearings so as to block the oil galleys that used to supply the balance shafts. I think it's time to port the oil relief!! I will report back soon with updates.

 

[ziggo0]

I'm in the same boat except I'm hitting 100 at 3k. Currently porting my relief.

 

[Shadow21]

Its fairly simple to do, Just remember to de burr the inside where the piston moves up and down. I used a dremel tool to do mine and i had a polishing bit that got the job done nicely.

 

[red1993gsallmt]

my oil pressure was maxing out at 150ish, porting diddnt help much but cutting about 2 loops off the spring did the trick, got it to 18-20 at idle and 75-80 at redline. I killed two turbos due to high oil pressure. Buy a mech oil pressure gauge, it takes the guessing out of it, my stock gauge said everything was fine, the thing that clued me in was the senders would keep going bad so i finally got a mech one, boy did that solve the turbo slaying mistery, i killed a bullseye 57trim and a fp18g both in less then 2000 mi, now my holset has over 9k and it is still good as new

 

[JusMX141]

^ ^

Proof positive that too much oil pressure is fatal for any turbocharger, no matter the brand.

It's also proof that knowing what is going on with your engine at all times will reward you with long engine component and turbo life.



The pressure relief valve is basically a bypass for the oil system that bleeds off excess oil pressure back into the pan. It's essentially a wastegate for the oiling system. Porting the hole allows more oil to pass through the hole and into the pan (much like porting the wastegate hole offers protection against boost creep), but trimming the spring may be necessary to gain full control of the pressure. Don't be afraid to tune your oiling system as red1993gsallmt did if necessary.

 

[Yamahaulin]

I ported my ofh and got it down but I still see 100 at redline. Maybe i should trim the spring back as well.

 

[alice]

I am fairly worried about blowing the seals in my turbo with this high oil pressure. I have a MHI 16g and from what I remember it seemed to have a restrictor in the CHRA of the oil feed. The hole in the CHRA where oil flow into seemed tiny and looks as if it is a restrictor. Any truth to that?

 

[red1993gsallmt]

I ported my ofh and got it down but I still see 100 at redline. Maybe i should trim the spring back as well.

cut a half loop at a time, remember you can always cut more off, but you cant put it back on

 

[JusMX141]

I have a MHI 16g and from what I remember it seemed to have a restrictor in the CHRA of the oil feed. The hole in the CHRA where oil flow into seemed tiny and looks as if it is a restrictor. Any truth to that?

It's not a restrictor. It simply feeds the appropriate amount of oil to the journals. You still need to control the pressure reaching the turbo.

Yes, MHI turbos can be over-oiled.

my oil pressure was maxing out at 150ish.... i killed a bullseye 57trim and a fp18g both in less then 2000 mi, now my holset has over 9k and it is still good as new

 

[jed344]

im seeing about 20psi at idle about 45ish on highway at 60 so thats between 2500-2700rpm is it i cant remeber that normal? and usually bout 90psi at wot think i need to lower it any or safe as is?

 

[alice]

I am using the SBR 16g install kit that came with the SS line to feed from the OFH so what restrictor do I need? I was thinking .080?

 

[ziggo0]

Ported my relief as well as cleaned it up. I would normally see 100+psi by 3 ~ 4k rpm, idle is down to 15psi from 25 ~ 30psi, and no more than 85 ~ 90psi by redline.

 

[alice]

Ported my relief as well as cleaned it up. I would normally see 100+psi by 3 ~ 4k rpm, idle is down to 15psi from 25 ~ 30psi, and no more than 85 ~ 90psi by redline.

Do you have any pics of how much you ported?