Oil pressures down!!!!!! Finally

[bazeng]

thanks for the info!
will be giving it a shot on the weekend!!

 

[steve]

2000 35
2500 45
3000 55
3500 65
4000 70

Car fully warmed up on my way home last night, BS in, stock oil setup, gauge tapped at stock oil sender location, Mobil 1 10w30 (still have to verify that 100%)

Hope that helps. I can get some higher RPM #s too, but I rarely visit that realm. /ubbthreads/images/graemlins/wink.gif 13g powah y00000

 

[powerplay]

Thanks Steve. That give us a baseline for the stock system oil pressures.

 

[atc250r]

Only 5 psi lower due to the balance shafts shows that what I suspected was true. They don't make that much of a difference and if you consider that Steve's motor has at least 60 or 70 thousand miles on it then it probably doesn't raise the pressure at all.

John

 

[powerplay]

John, before the porting I was always 70 psi and above. So stock is 55 psi and after BS removal it goes up to 70 psi at 3K. Am I miss understanding this? That looks like a 15 psi difference. I am now 60 psi at 3K, which is close to stock again. Correct me if my thinking is whacked!

 

[atc250r]

Mine was 60 psi before the porting and as you stated the pressure below about 75 psi should be unaffected.

John

 

[powerplay]

Well that seems strange. It appears your pressure only went up a little after removing your BS. Mine went up 15 psi, if we use Steve's numbers as a base line and we know Boostin' went up in a similar manor. So you went up to 60 and then you ported and it went down to 55. It would seem like you didn't have the problem we had. I not sure you had to port your housing. My problem was pressures on the order of 80 and more at highway speeds. Well whatever, it appears to be under control now. Thanks for all of your input.

Scott

 

[atc250r]

I think there is a little confusion Scott. Mine didn't really change when hot with the ported housing, the pressure stayed right around 60 psi at 3000 rpm. Steve's stocker is seeing 55 psi at 3000 rpm. The porting helped me more when the car was cold which was when I would see in excess of 100 psi by 3000 rpm.

John

 

Excuse me if im stupid here.
If Mitsu built an engine WITHOUT balance shafts, what would be the remedy(from factory)for the high oil pressure for such engine?

 

[atc250r]

Very good question and I think if you looked at a 4G61(where we get our block off kits from) the oil pump would be the same as the 4G63. Overall I think this whole thing is being given way more research than it deserves but its fun to fiddle with sh*t!

John

 

[bazeng]

i've discussed this issue with a rally friend of mine, so far he says the pressures should increase only slightly.. he said if its going to 100 psi, thats really bad, but he believes that all the bs removals he has done hasn't really changed pressure at all

he said 5psi at most!

i will most likely wait till i get it up and running, and if pressure are high ill port it, if not, ill keep it as it is

also many of the balance shaft removal guys down here have kept the shaft in, so their pressure are all stock like..

would reversing the bearings really increase pressure by 30 or so psi?!?!?!

question, 100psi cold, what is it warm??

from what i recall, on my old motor (250,000kms) i also remember my gauge going up to 100psi cold start.. i thought i was normal back then..
5-50 oil..

 

[G]

now i'm wondering since the 4g61 has no bs's how does it deal with this ?
they come with the cap installed here :



does the block not have oil passages ?

 

[atc250r]

The 4G61 has a block off bearing for one reason, they do have passages and they need to be blocked off /ubbthreads/images/graemlins/grin.gif. Even if they don't if that's the only difference then the pressure would be just as high. I think a lot of the info has gotten lost in the size of this thread so here's the bottom line:

Steve has a STOCK set up with nearly 100,000 miles and he sees 55 psi at 3000 rpm. I have a BS eliminated set up with about 20,000 miles and I see 60 psi at 3000 rpm with both the stock and the ported housings. We are both running the same gauge tapped in the same place with a similar weight oil.

Bazeng's friend's guess of a 5 psi difference is about right. What had me nervous was the 100 psi and up on cold start but I was scared of oil filter explosion or turbo bearing damage due to it. The ported housing got that under control as long as I keep it under 4000 rpm when cold.

John

 

[powerplay]

I agree this may have been investigated more than need be, but it is interesting to see the differences. I posted my findings in the beginning of this thread:

"I installed an oil pressure gauge this weekend and found similar results to Boostin'. I have 20psi at 800 rpms, fully warmed up. At 60mph, in 5th, I have 80psi and it easily climbs to 100psi if accelerating"

I was seeing much higher oil pressure than what was normal. By porting the housing I went from 80 to 65 psi. It is clear that my relief valve was not able to flow enough oil to relieve the increased pressure with the stock bypass hole. That is why I ported mine.

I don't understand why, in John and Bazeng case, their's was only a 5 psi difference when fully warmed up. My pressure was 80-100 at 3-4K rpm at full operating temperature. Since I have ported it, I no longer have high oil pressure when cold either. My oil pressure stays at 65- 70 psi regardless of operating temperature.

I would agree with Bazeng, put the housing in, see what you have for pressure and decide for yourself if it is necessary. In my case, for whatever reason, it seemed to be warranted and it works fine now.

 

[G]

ATC, the 4g61 doesn't use a bearing though it comes with a cap similar to a freeze plug. that's why i was wondering if it had oil passages @ all.

also do the 4g61's have oil squirter's ? if not then the block is definitely different.

 

[atc250r]

I'm not sure about the squirters but I was actually thinking about them on my way home from working on my car today. The non turbo models have no squirters and the same oil system, I would think the squiters would be more of a bleed off than the BS's are but those motors are damn near indestructible.

John

 

[bazeng]

quote from NZMMC user:

Ive got a forged vr4 engine with balance shafts removed and bearings turned. all new gaskets etc and the presures are as follows

Cold idle (1500rpm) about 80.85 psi
Warm idle (800rpm) about 14.7 - 22.05 psi
Cruise (3500rpm) about 44.1 psi
7000rpm about 102.9 psi

hmm, another 100+ psi engine with balance shafts removed..

whats going on here?
it seems very random.
some people have the problem, some dont?

 

Yes 4g61t engines have oil squirters as do all higher compression NA engines (aka all the ones we don't see in the states) There is a big thread on this on 4g61t.org.

I'm not sure if they drilled out the passage for the BS bearings on them though. My old 4g61t block is 100 miles away so I can't go check. Just look on the front BS "hump" for the plug that indicates they drilled the passage out.

Just after I pulled the engine and before any cleaning etc
http://www.ce.rit.edu/~mezz/gallery/rebuild/img_1325
You can see the little bump there in the middle of the block. It is a set screw completely covered in goo /ubbthreads/images/graemlins/smile.gif

-paul

 

[G]

THAT'S a 4g61 ? why does it have bs's ?

can you check for the set screws on your 4g61 for me ?

i don't own one yet.

 

Pictures in my previous post are of a 63t showing the 'nubbin' for the oil passage

I don't have any pictures of my 61t without the manifolds on it.

-paul