The openning is a lot smaller than it looks on paper, a dremel with a 1/8" shank metal grinding stone will do.

old man , so those pictures looked like they were of a oil pump? Or can i see this where i need to port when I take off the filter... ( I have a 90s 6bolt with no bs... ) I dont know my oil pressure though because im using the stock gauge and I know its not very accurate...

Those are pictures of the oil filter houaing, not oil pump housing. You have to remove the oil filter housing which is attached to your front case, not just the filter.

With the oil pressure relief hole the trick is to widen it not make it longer, so the original hole do not lengthen it the same length ways as the piston travels, use the original hole as a guide just make it wider!!, very high oil presures cause what is know as an oil wedge on the bearings which can cause a bearing to spin. a good formula with oil pressure is 10psi per 1000 rpms that keeps things happy.

so what are the chances of an ill effect on the engine say I didnt do this porting?
I know a lot of ppl remove their balance shafts but dont know the percentage who do this also along with that..

Actually i have the same question as above. Because i've read a lot about balance shaft removal, but nothing in turn of this porting.

What the dilly yo?

I just wanted to put my .02 in. For those of you that posted "I'd rather have volume than pressure" Here's your sign. There is no pump out there that "creates" pressure, instead they produce VOLUME. Pressure is created by the opposition to flow. No opposition, no pressure. Think of a water hose flowing freely, there is essentially no pressure at the end of the hose. Now put your finger in front of it and watch the water soar! Now you have pressure. And yes, too much pressure is a bad thing. As it was explained to us in school, too much pressure will actually push the oil out of the bearing and can cause metal to metal contact. Bad deal. So those with 100+ psi I'd do something to remedy that quickly.

Here is a link to some pics of the oil pressure relief porting I found on the Dsmlink forums.

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

When you take it apart you'll understand it a lot better. Just making the hole larger usually doesn't work, you'll want to port it just like in the picture. Making it wider did nothing for me, I tried this a few different ways before I got it to work right. First I just drilled the hole larger and oil pressure stayed the same, Then I ported the hole wider and a little longer, this dropped oil pressure about 5 psi throught the RPM range. Then I went all out and ported it the direction of piston travel as far as I could. This dropped oil pressure to acceptable levels

With the oil pressure relief hole the trick is to widen it not make it longer, so the original hole do not lengthen it the same length ways as the piston travels, use the original hole as a guide just make it wider!!, very high oil presures cause what is know as an oil wedge on the bearings which can cause a bearing to spin. a good formula with oil pressure is 10psi per 1000 rpms that keeps things happy.

Click to expand...

The oil wedge is the actual film of oil between the bearings and the main/rod journal. The bearing clearances, oil volume, and oil viscosity are what maintain that wedge of oil. Not having that wedge is what causes bearing damage.

My car has stock like oil pressure with balance shafts removed, kinda worries me

Spoolin4Ever said:

My car has stock like oil pressure with balance shafts removed, kinda worries me

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Was it a complete removal?

Spoolin4Ever said:

My car has stock like oil pressure with balance shafts removed, kinda worries me

Click to expand...

Are you using the stock gauge?

GVR4592 said:

Are you using the stock gauge?

Click to expand...

Are we talking to ourselves?

GVR4592 said:

Here is a link to some pics of the oil pressure relief porting I found on the Dsmlink forums.

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

When you take it apart you'll understand it a lot better. Just making the hole larger usually doesn't work, you'll want to port it just like in the picture. Making it wider did nothing for me, I tried this a few different ways before I got it to work right. First I just drilled the hole larger and oil pressure stayed the same, Then I ported the hole wider and a little longer, this dropped oil pressure about 5 psi throught the RPM range. Then I went all out and ported it the direction of piston travel as far as I could. This dropped oil pressure to acceptable levels



The oil wedge is the actual film of oil between the bearings and the main/rod journal. The bearing clearances, oil volume, and oil viscosity are what maintain that wedge of oil. Not having that wedge is what causes bearing damage.

Click to expand...

So of the three pictures provided, what your saying is to port it like the first picture? The one all the way on the left?

so are you guys telling us that theres really no way to port it too much as long as you aren't going bigger than the pic? will too much porting cause your oil pressure to be low? are ALL new motors with balance shafts removed going to get this overly high pressure?

thanks guys, i'm acually in the process (just finishing up) a new 6 bolt motor with no balance shafts. let me know now im worried!

Spoolin98 said:

So of the three pictures provided, what your saying is to port it like the first picture? The one all the way on the left?

Click to expand...

Yes, sorry I should've said that in the first post.

Boosted4 said:

so are you guys telling us that theres really no way to port it too much as long as you aren't going bigger than the pic? will too much porting cause your oil pressure to be low? are ALL new motors with balance shafts removed going to get this overly high pressure?

thanks guys, i'm acually in the process (just finishing up) a new 6 bolt motor with no balance shafts. let me know now im worried!

Click to expand...

In most cases, yes oil pressure would be too high. Porting it isn't as difficult as it might seem. Once you get the piston out you will see how much material you can remove from the housing. Just don't go past the top of the piston or oil pressure will bleed off constantly. The relief valve was designed to open at 78 psi, which is 10 psi per 1000 rpm's. It's basically the same as putting a 255l/ph fuel pump on your car without a AFPR. The relief hole gets overrun and pressure goes up. You need to increase the size of the outlet to compensate.

GVR4592 said:

Yes, sorry I should've said that in the first post.

Click to expand...

Thanks Luke.
So if I port it like the first picture I should have average oil pressure, 10psi per 1000rpms? My concern is that I don't want to have too low oil pressure.

When people are hitting 120ish-psi without the porting, and more realistic #'s when the work is done, i'd assume there won't be an issue with "too low".

I could be wrong, but i'd assume this wouldn't be a reccomended thing to do unless it was necessary. It may be an easy job, but it's a little bit of work to get it done.

I will definitely be doing this while my motor is out though. As well as adding a filter feed like to my turbo (as opposed to the head).

Thanks everyone who has helped everyone including myself. Last thing i'd wanna do is chunk a new motor due to TOO MUCH oil pressure.

oldman said:

Are we talking to ourselves?

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Sorry got a new email adress so no notification was received.

With a mechanical gauge it shows about 12 psi hot idle. Balance shafts are completely removed.

Stock gage only goes just abovethe first mark at cruise, idle hot will stay way down to the L. My stock gauge seems fried. I replaced the sensor with a used one, not sure if it is a good one or not. It behaves the same as before.

Spoolin98 said:

Thanks Luke.
So if I port it like the first picture I should have average oil pressure, 10psi per 1000rpms? My concern is that I don't want to have too low oil pressure.

Click to expand...

The stock oil pressure relief valve (the part with the spring and plunger you take out when porting) is setup to roughly give between 70 and 80 psi max. The problem with balance shaft removal is that you have more volume of oil going to the pressure relief since the shafts (or squirters) are blocked off now and not using any of the pressure. Thus the hole, that is shown in the links above, needs to be opened up to allow more of the volume through when the stock relief valve opens up.

As long as the relief valve seals I don't think you should ever have a problem with too low as it should stay closed until the spring pressure is over come by the oil pressure, again stock is aroun 70 to 80psi.

LaserAWD said:

The stock oil pressure relief valve (the part with the spring and plunger you take out when porting) is setup to roughly give between 70 and 80 psi max. The problem with balance shaft removal is that you have more volume of oil going to the pressure relief since the shafts (or squirter's) are blocked off now and not using any of the pressure. Thus the hole, that is shown in the links above, needs to be opened up to allow more of the volume through when the stock relief valve opens up.

As long as the relief valve seals I don't think you should ever have a problem with too low as it should stay closed until the spring pressure is over come by the oil pressure, again stock is aroun 70 to 80psi.

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Wow, 2 posts in almost 4 years of membership? Nice, and I thought I barely posted compared to some people. I understand the concept of why you port it and how to. Your explanation of why I shouldn't have a problem with too low oil pressure makes complete sense, Thanks.

Spoolin98 said:

Wow, 2 posts in almost 4 years of membership? Nice, and I thought I barely posted compared to some people. I understand the concept of why you port it and how to. Your explanation of why I shouldn't have a problem with too low oil pressure makes complete sense, Thanks.

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Shorty after I joined up here my car spun a bearing, being in college I couldn't afford to fix it so I parted it out. Now I'm out of school and have gotten another Laser to play with so I'm back lurking on the boards and figured I'd help out when I see something I've done or know how to do.

Glad the explination helped With the b-shafts removed (or the squirters blocked) you're probably going to get that 70-80 psi by 4-5k rpms, but if you port it well enough you should be able to hold that until the stock rev limit.

LaserAWD said:

Shorty after I joined up here my car spun a bearing, being in college I couldn't afford to fix it so I parted it out. Now I'm out of school and have gotten another Laser to play with so I'm back lurking on the boards and figured I'd help out when I see something I've done or know how to do.

Glad the explination helped With the b-shafts removed (or the squirters blocked) you're probably going to get that 70-80 psi by 4-5k rpms, but if you port it well enough you should be able to hold that until the stock rev limit.

Click to expand...

Well I'm glad to hear your back in the DSM game. Good luck with your future modding.

Bringing back an old thread. I have a 6-bolt with a stock unported oil filter housing and using an aftermarket B&M oil cooler with -6 AN lines. My oil pressure when its cold is usually between 70-85psi and when its warm 20-25psi depending where it decides to idle that day. At WOT it never goes above 80 or so psi.

I didnt use a kit to delete the balance shafts, just just the balance shafts and turned the bearings. I just bolted back up the front gear to the front stubby bs I cut. Its been like this for at least 20k miles with no problems, just wondering if theres a reason why I dont see the high oil pressures that other people are getting with the BS delete?

seth98es said:

Bringing back an old thread. I have a 6-bolt with a stock unported oil filter housing and using an aftermarket B&M oil cooler with -6 AN lines. My oil pressure when its cold is usually between 70-85psi and when its warm 20-25psi depending where it decides to idle that day. At WOT it never goes above 80 or so psi.

I didnt use a kit to delete the balance shafts, just just the balance shafts and turned the bearings. I just bolted back up the front gear to the front stubby bs I cut. Its been like this for at least 20k miles with no problems, just wondering if theres a reason why I dont see the high oil pressures that other people are getting with the BS delete?

Click to expand...

It could have something to do with the actual condition, or build of the bottom end. I mean if the bearings were a little out of spec could affect that.

I am contemplating doing the porting of the relief valve myself because I dont want to throw on this new evo3 16g I have and mess up the seals because of too high of oil pressure coming from my rebuilt 6bolt with no b/s.

I dont have a aftermarket gauge hooked up, but the stock gauge at warm idle shows the need all the way up like 3/4ths of the gauge and anything over 4k rpm its sitting on the red zone of the stock oil pressure gauge... Some ppl say it wont affect my turbo considering its still tapped at the head, and I know the head recieves a lot less pressure but im sure if I should risk it. I may port it within the next 2 weeks but id like to hear any more experiences with porting of, and / or turbo seal, or any kind of bearing or other seal failure from too high of oil pressure,
and of all the ppl who do have b/s removed and havent had any problems ever with no porting or anything.