well i have a 6bolt with no balence shafts,right. i have an aftermarket greddy 60mm electronic gauge. the sending unit is right in my oil filter housing. well at idle im at about 30 psi pluis or minus 5 psi. but when im on it i gets as high as 120 psi or mabye even a little more. i have an external oil cooler and i run a 1g oil filter K&N. so is this really high or normal with my setup??

I'm not going to be able to comment on this, but for everyone's reference what was your oil pressure before?

like 7 psi at idle and like ###### like 60 to 80 in boost. but thats with a 7bolt w balence shafts

I don't have an aftermarket oil pressure gauge but the stock gauge gets 3/4 up on the highway or after a wot pull. It's alot higher than it was on my stock 7 bolt which barely got passed the halfway point.

ya mines the same way my stock gauges goes like 3/4 up so it must be normal then even if its not i dont think there is much i can do about it

That is normal oil pressure without the bshafts. I have a built 6bolt no bshafts and i get 30psi or so when warm and up to 120psi at wot. If you want to relieve the pressure a little bit you can always port the oil bypass valve in the oil filter housing. However i have heard that even if you do this it doesn't mean it will lower the pressure by much. I have not ported mine yet but the car has been running with that kind of oil pressure for a year now and no problems whatsoever.

thanks for the heads up!!

Yeah, the balance shaft removal definitely bumps the oil pressure a good deal. Shit, that's nothing, you should see my buddy's car which has a stroker with no oil squirters. No lie, his stock oil pressure gauge is maxed out at idle.

dam!!!!!!now thats high

hmmm this is interesting.

I have no balance shafts and my oil pressure are 2 psi at idle and 30-40 psi at wot reading off from Summit Racing digital gauge w/ Summit oil pressure sender. Always thought i had issues with the gauge since the read out seemed low. I'm running Mighty Max oil housing so i have no space for other senders so no stock oil pressure gauge.

My sender is @ the head

Our reading is at the oil filter housing so it explains why yours is real low.

is there any ill effects of the oil pressure being "too high" or is it only when its "too low" that there is a problem. Also mine reads about 30 at a warm idle and 90-120ish during wot.

Actually low oil pressure is kind of a myth. Typical cars run about 5psi of pressure at idle. No joke.

I just did the test on a few different GM and crysler cars and it's true. 3800's and northstars included.

If it got REALLY low i'd think there were issues. Like 1-2psi.

I would imagine HIGH pressure would be very bad though too. But i'd rather have volume than pressure. I just ordered my block with no BS's for reliability and less rotating mass.

Think of BS removal as EVO III turbo upgrade, high oil pressure as boost creep and the oil pressure relief valve exit path as wastegate path. Porting of the pressure relief valve should be done with BS removal just as porting to EVO3, you can also think of this as FPR overrun. Enlarging the valve exit will allow the oil pressure regulating system to work as it should.

What is involved with doing the porting on the valve then? Because if i'm getting a new motor with no BS i don't want it to chunk because i didn't do something necessary to prepare for no BS's.

Very simple, flip the oil filter housing and follow these pics.

http://www.utdsm.org/gallery/view_album.php?set_albumName=album12

So how large does it realistically need to be? Because one of those was HUGE!

And hopefully i'll have time to get at this while my mechanic is pulling stuff off my old block.

Thanks for the help yet again Oldman. This was totally new to me.

The small one being 0 and the large one being ten, mine was an 8. You really don't have to worry about too large as long as you stay below the tip of the relief valve because it will not open until certain pressure is reached and the spring of the valve is overcome to expose the exit path. In other words, why worry about the wastegate path being too large as long as the flapper is sealing.

Alright cool, I'll shoot for around a 5 maybe on the "scale". Thanks again for the help.

staticbrainwash said:

Actually low oil pressure is kind of a myth. Typical cars run about 5psi of pressure at idle. No joke.

I just did the test on a few different GM and crysler cars and it's true. 3800's and northstars included.

If it got REALLY low i'd think there were issues. Like 1-2psi.

I would imagine HIGH pressure would be very bad though too. But i'd rather have volume than pressure. I just ordered my block with no BS's for reliability and less rotating mass.

Click to expand...

The "oil pressure low" light/switch should come on at around 5psi on a DSM and Toyota (can't speak for domestics). Normal idle is supposed to be in the 10psi range, IIRC (I've been through oil pump failures in my MR2 AND DSM in the last couple years...).

In the case of my DSM, the oil pressure light would occasionally flicker at idle. It was a warning that the oil pump was dying and my oil pressure was hovering in the 5-6psi range. Only did that for a thousand miles or so before it seized up. No engine damage. Replaced with a factory HV pump this time. Volume is definitely more important than pressure, but pressure needs to be within a certain range too (high volume can prevent you from losing pressure on an engine built to sloppier tolerances, such as forged pistons, a "nitrous build", etc.)...

In the MR2, the light would stay on after starting the car when it had been sitting for around 15 minutes and restarted (so, low idle, nice warm engine). "Rebooting" the car would make the light shut off, so we thought it was an electronics issue. Oil pressure sender found to be leaking, so that was replaced. Problem persisted, and we just ignored it since restarting the car "solved" the problem. Another early indicator of a failing oil pump... Over the next 2 years the car gradually developed a slight rod knock. Nearly 3 years after the original symptoms it finally got to the point of needing rebuilt. That's when we found that the oil pump was only pushing 6-7 psi at idle, and much less than it should at rpm (not enough to trigger the light, but enough to lunch the bearings).

The issue with high oil pressure is the possibility of blowing off a connection (unlikely) or filter (somewhat likely). I'm also told that some turbos don't agree with high oil pressure and it will damage the seals, but I can't confirm nor deny that at this time

well i already blew my oil filter off once and i hope it dosent happen again!!!!

1LE said:

The issue with high oil pressure is the possibility of blowing off a connection (unlikely) or filter (somewhat likely). I'm also told that some turbos don't agree with high oil pressure and it will damage the seals, but I can't confirm nor deny that at this time

Click to expand...

You're also putting undue stress on oil pump gears and cover causing possible earlier failure, but you're correct that the most immediate concern is filter blowing off and turbo seals (as well as other gaskets and seals) failures especially when feeding from the filter location. The results of proper porting should be the following.

Idle : 20psi (porting seems to have no effect on the idling pressure increase which is great).

cold start : 70psi instead of 100+psi.

WOT : 70-80psi instead of 120psi.

I know this is some what new to tuners but it's certainly not new to DSM.

do you think you can post a how too for porting the oil fliter housing. and show us guys where and how much to port?? thanks a lot!!!!

GstRacer said:

do you think you can post a how too for porting the oil fliter housing. and show us guys where and how much to port?? thanks a lot!!!!

Click to expand...

Josh, the process is fairly simple.

1. Follow your service manual to remove the oil filter housing, a little more difficult for 91'+ cars, may have to loosen the upper mount and drop the engine a little.

2. Remove oil pressure relief valve from the housing, good idea to replace the crush washer on the bolt.

3. Enlarge the exit path that leads back to the oil pan, make sure to stuff paper towls to block off internal passages prior to porting. Once you have the housing in your hand, it will become apparent that there is some distance/travel between the valve pluger (where it seals against the housing) and the exit opening. The key here is to enlarge the opening while bringing the opening closer to the plunger without coming to close to affect proper sealing. I didn't take any pictures so you will have to settle with the above link which is pretty much self explanatory, it seems confusing now because you don't have the housing off yet.

4. Clean the housing thoroughly, replace the gasket and torque everything to spec, remember you're dealing with an aluminum housing.

5. Prime the system and you're done, the whole thing should take about 2hours but take your time with it.

Since it's aluminum what kind of bit would you recommend we use to port? Because carbide would probably destroy the housing.