Speednz

Anyone else have issues with high oil pressure? Im not referring to the 10 already existing threads of people worried because their stock gauge pegs, I mean genuine issues with having oil pressures up past 120. I havent yet, but plan to hook a mechanical gauge up to sensor port to see where the pressure actually peaks at.

For example, I built my DE, .002 main clearances, ACL race bearings (mains and rods), and have a rev up oil pump. I have never seen my oil pressure below 30 (60 cold) after build, before build maybe 10 psi. I run 0-40 mobile European synthetic.

I had no issue with these numbers, until I started to put my turbo to work. Turbonetics 62 series ball bearing with a restrictor on feed, and the return drained to a AN I welded to top of oil pan. The car doesnt smoke until im at or near redline, then oil seems to seep on cold side of turbo. This puts a film of oil inside charge pipes and occasionally pisses off my HPX MAF.

Sorry for the drawn out explanation, but what im about to propose is kind of out there and people may think its crazy. Ive looked through the exploded diagram of the oiling system on a DE, the pressure is strictly controlled by the oil pump. A very simple regulator valve spring and valve controls peak PSI before dumping excess. Has anyone ever heard of getting a lighter spring to reduce peak PSI? This would only be even considered due to the fact im running tighter clearances on a built motor. Also worth noting, I did not have this issue until I built heads with ferrea valvetrain and raised rev limiter.

You may say "get a different turbo". I have 700 miles on this turbo. I have spoken with turbonetics and they always try and blame it on a restriction in the drain, which I dont have.

bealljk

iTrader: (13)

Interesting post...

Post what you read on a mechanical ... even when I'm hitting hard (6k rpm / 12psi) I think my OEM gauge is near 120 and my aux pressure sensors are near 90 to 100psi (many reason on my build why this is).

30 psi, cold, at idle, zero load? Isnt that double what OEM specs out?

I'll say it...seals in turbo maybe starting to go??

Why are you running a 40 weight? Could you put in a lighter weight oil as a test to see how your engine reacts?

dkmura

iTrader: (64)

He's using the M1 0-40W, which pours more like a 30 weight oil, but flows easily at startup. A pretty good choice, IMHO.

NissanTracker

iTrader: (8)

I agree, especially for a turbo set up. I saw oil pressure top out to ~100 psi at cold start up with a single turbo w/ M1 0-40w.

My 07 nismo with a 34 row cooler + Stillen S.C. see's around that as well at cold start. AT WOT and warmed up... ~90 psi?

rancor

I would guess you would not want to decrease the spring in the bypass unless you are running the Revup pump in case you could switch out springs for the normal DE. I wouldn't feel very comfortable reducing oil presure on a turbo motor. Could you use a smaller restrictor for the turbo or add a scavenge pump on the drain line?

iideadeyeii

iTrader: (6)

He already has a restrictor per his first post and a scavenge pump would never fix a direct drain smoking turbo issue.

What size an fitting on drain? Also, on my fake tn kit(godspeed) I just run 10-30 full synthetic (whatever is cheapest) with a oil pan spacer that has a fitting built in and I have no issues

NissanTracker

iTrader: (8)

I agree. Ball bearing turbos are very picky with input oil pressure, so he would have to check with the turbo manuf.

Scavenging oil is almost a must. A small reservoir between the oil drain and the scavenge also is recommended. In the event the car is turned off, oil will drain to it. I added a inline transmission heat sink cooler. Helps with the life of the scavenge pump (reducing oil temps before entering the pump) and if the car shuts off, it serves as a "catch can". Just add a breather tube to it and your all set.

Another option is an electric cutoff switch after the scavenge pump. This should be normally closed. When the car turns on, valve opens... car off, valve closes. Any oil after the scavenge pump will not "gravity feed" back to the turbo (bearings).

I always add a turbo timer as well.

I used the above with my APS turbo kit which faced issues with oil sitting on the intake side once in a while.


I believe with the OP's set up and choice of oil... that is what he will see for pressure.

@OP. What are you seeing for oil pressure at

First Startup (Idle)
Warmup (Idle)
3rd gear at 3K rpms (cruising)
WOT

NissanTracker

iTrader: (8)

The cooler and cutoff can be found in the pics of my turbo kit listing on ebay. APS at one point was including the cutoff as a solution for the oil sitting in the intake side.

https://www.ebay.com/itm/26330337230...84.m1558.l2649