oil pressure drops in WOT....?

M

mk3-4-me

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So I obviously want to fix/solve the issue, but I'm just wondering for peace if mind.

Is it all that bad to rip it when the pressure drops? What does oil pressure go to on a stock non-shimmed oil pump under WOT? I can't suspect anything more than 20 psi, and it's not like there's no pressure. Just drops from about 30-35 to about 15-20. I'm just trying to figure out if my engine is still good for future abuse! Lol
 
IBoughtASupra

IBoughtASupra

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For reference, I get 60-70 on a cold start up with 50F temperatures.

At operating temperature idle, 190F, I get 20-22 PSI.

At Cruise around 2000-2200RPM I get 50 PSI.

In boost pulling to 8000 RPM, I get over 80 PSI. Can't really watch it as I have to keep my eyes on the road. I do have a peak feature and it was close to 100 PSI.

My engine was just rebuilt with new bearings, HKS 264 Cams and a new Toyota unmodified oil pump. Those are the few things mechanically that would affect oil pressure. Obviously, new gaskets were used anywhere that needed one.
 
M

mk3-4-me

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Really? I've never heard of those amounts for our cars. And I search alot of stiff everyday just to get as much knowledge as I can. Lol well from what I've read, people that shim the oil pump have the same pressure as me for everything. But idk about this drop in pressure under WOT.

Pulling to 8k rpm? Are u talking about a JZ or a 7m?? Lol

Right now as I type this I'm in my car waiting for it to warm up... And I have just under 40 psi with 36 degrees here. But it was at that pressure even in the summer upon start up, so idk what that has to do with it. Lol
 
Devin LeBlanc

Devin LeBlanc

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I think he's talking about a JZ.

I get 80 psi cold start on a built 7M with proper bearing clearances. 18 psi full hot idle, and 60 at 3,000 rpm's

Brand new factory oil pump shimmed 5mm, No oil squirters, Oil filter is directly on the block.
 
M

mk3-4-me

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Ok well I just found an old posting that I posted my clearances in.

Mains in MM:-

1- .038
2- .038
3- .038
4- .04 (not exactly sure, it's just a tad smaller than the .038 marker)
5- .038
6- .038
7- .038

That's all within the spec from what I've read.

I can find the rods right now bit I know those where good to.
 
M

mk3-4-me

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So why would my oil pressure be that different? I shimmed mine 4.6 mm. But I don't think it would be 30 psi difference at cruising at 2k rpm. I'm at about 30 psi cruising.
 
IBoughtASupra

IBoughtASupra

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Have you changed the oil and refilled with five quarts? What grade oil are you using? Use the Toyota filter to rule out an issue with that. Any leaks? How is the gasket in the pick up in the pan?
 
M

mk3-4-me

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ok well im planning on doin an oil change in 2 days when i have off work. Im using 10w30 Castrol for the break in. I do have an oil leak coming from somewhere, but i have been checking every single time before i start up my car and top off as needed.

HVYMAN on the 2nd page just said that toyota filoters dont filter well at all, so im not going to get one of those. lol i will try a WIX and see if that does anything, but i read that supertech was a great filter by J-Dub in the oil section a while ago.

I used RTV black sylicone to do that oil pan, cause i read that the regular cork gasket sucks, and that RTV works good. I may have a leak from there somewhere but i put a nice thick bead when i put it on.

Im scared to go to 0w-40 GC now that there may be a problem. But i guess id rather my engine to go now in the winter, so i have time to get it ready for summer this time! lol But hopefully i wont.
 
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M

mk3-4-me

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I forgot to mention this. So I have the sandwich plate on my stock oil filter thing. But there is a metal pipe extention that would of connected a hose to the stock oil cooler. Right now that is plugged off because I have 2 lines coming from the sandwich plate to my oil cooler. Would that have anythin to do with this??
 
M

mk3-4-me

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And I have both ports/lines from the sandwich plate going to my oil cooler. Is that fine? Or does one need to drain back inti the pan like stock routing??
 
IBoughtASupra

IBoughtASupra

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The stock extension housing is a cooler by itself. Notice the two runner hoses going to it? Those are coolant hoses.

You added a cooler to a cooler, which is obviously incorrect. Remove your setup and put you oil filter back on. I am not sure if this would cause the problem you are having but what you are doing is not really helping either cooler.

Either remove the oil filter housing and use the sandwich plate to the block OR remove the sandwich plate from the oil filter housing and screw your oil filter back on.
 
M

mk3-4-me

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Ok well I don't think were talking about the same thing then. Cause I dnt think there are any coolant lines going to my "extension housing".

And the sandwich playe just allows for extra lines to be used I think. My filter is in the same place, just spaced with the sandwhich plate. Maybe i was using the wrong term...? This thing doesn't cool the oil...well unless you count the fact that the 2 lines coming from it go to my oil cooler.
 
CyFi6

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IBoughtASupra;1778608 said:
No. Change your oil and full it with five quarts.

Second, why did you shim the oil pump? JZ owners actually modify the oil pump to lower it's oil pressure that it produces at higher RPMs since it blows out the front main seal? If they didn't modify it to lower the oil pressure, they add a screws around the ring that holds the seal in place.
Click to expand...

IBoughtASupra;1778670 said:
It's done by SP. I meant to say, it goes around the ring of the seal, not that they add a ring.

http://www.spracingonline.com/images/products/3623.jpg
Click to expand...

IBoughtASupra;1778810 said:
For reference, I get 60-70 on a cold start up with 50F temperatures.

At operating temperature idle, 190F, I get 20-22 PSI.

At Cruise around 2000-2200RPM I get 50 PSI.

In boost pulling to 8000 RPM, I get over 80 PSI. Can't really watch it as I have to keep my eyes on the road. I do have a peak feature and it was close to 100 PSI.

My engine was just rebuilt with new bearings, HKS 264 Cams and a new Toyota unmodified oil pump. Those are the few things mechanically that would affect oil pressure. Obviously, new gaskets were used anywhere that needed one.
Click to expand...

IBoughtASupra;1779053 said:
The stock extension housing is a cooler by itself. Notice the two runner hoses going to it? Those are coolant hoses.

You added a cooler to a cooler, which is obviously incorrect. Remove your setup and put you oil filter back on. I am not sure if this would cause the problem you are having but what you are doing is not really helping either cooler.

Either remove the oil filter housing and use the sandwich plate to the block OR remove the sandwich plate from the oil filter housing and screw your oil filter back on.
Click to expand...
I'm not sure if you realize that this is in the 7mgte section.
 
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