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Discussion Starter · #1 ·
In an attmept to avoid the oil starvation issues I've heard about with the 7M, I took my oil pan to a local shop that manufactures oil pans (among other things) for race engines. The owener thinks that the screen and pick-up tube on the oil pump are way too far from the bottom of the pan. I haven't measured how far the screen sits off of the bottom of the pan, but he said they built pans so the pick-up tube sat 1/4 -1/2 inch off the bottom. The 7M has more than a 1/2 inch between the screen and the tube itself.

He also recommended cutting the stock pan and welding in another inch or two to allow the pick-up to sit in even more oil. He thought adding more baffles would probably be a waste of time. Lengthening the pan and the oil pump pick-up tube should be enough to greatly reduce the possiblity of oil starvation.

I'm going to take some measurements of the pan and pump this weekend and drop them both off to him next week for welding. I'll post results ASAP.

Dale H
87-T
 

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I think the N/A oil pump is a drop in replacement. And that has HIGHER oil pressure than the turbos pump. :)
 

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VIPER HUNTER
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there is another thing about this.I got word that toga oil pumps suck.Next the shimming dont help idle oil pressure just full throttle oil pressure.

moroso makes a oil accumalater that is really good.Thats what im gonna run.It suplys oil when the pressure drops below a certian level
 
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I think the N/A oil pump is a drop in replacement. And that has HIGHER oil pressure than the turbos pump. :)
Higher oil pressure but lower volume...I'll take the turbo one.
I don't buy it.

Looking at the TSRM all the oil pump specs are applicable to both turbo and N/a engines.

Looking at the parts catalog, there are different part numbers between many years/models of the MKIII, for the oil pump, however I'm not sure why.

http://www.cygnusx1.net/supra/library/EPC/MKIII_NATO/parts/15100.html]

That aside....

Since the head is identical on Turbo and N/a, and the engine block CASTING is as well, there cannot be a "high volume" and a "high pressure" oil pump versions.

Simple physics: Oil is incompressible (for all real world purposes).

Only way to get more volume of oil through a given passage size(bearing, hole, duct, etc) is to increase the pressure.

Given the Turbo/Na have the same size of oil clearances in the bearings, oil galleries etc (same castings), then you cannot supply more oil through them, UNLESS YOU HAVE HIGHER PRESSURE.



What is different though, is the fact that the Turbo has many more "bypass" routes for the oil, to short circuit past the engine, and back into the oil sump (oil cooler, turbocharger, oil squirters).

http://www.cygnusx1.net/supra/library/TSRM/lu/LU_02.html

That is why there seems to be a difference in pressures measured at the gauge (and there actually is a difference, but the oil pump is doing the same work).

Please correct me if I'm mistaken (really not a smart ass comment, I'm curious).

Cheers....Sdude.
 
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Boostin88T said:
You can modify the drive gear on the oil pump to get higher pressure out of it. My machine shop guy is looking into it. But it can def be done.
I remember reading that thread where this was discussed, but for the life of me I cannot find it anymore, using the search function.

:mad:

Can somebody point me to the thread, please? I had an idea to add, that could be useful.

Thank you....Sdude.
 
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Shawndude I totally agree with your theory. Given that the gte pump is moving a larger volume of oil due to the turbo, oil cooler, and piston squirters, if its the same pump, it would operate at a lower pressure. Why everybody is so concerned about there oil pressure I don't understand, toyota thought it was enough and the fact that 200K+ miles is a common occurance with the 7m-gte I would concur. The best upgrade imo to the oil system would be a bigger sump to deal with the added volume of oil that is constantly moved.
We all now from dealing with pressure vs. volume with turbos that higher pressure doesn't always mean more flow. The gte was designed with a higher volume in mind allowing for an overall lower oil pressure. All shimming the pump or attempting to increase pressure is going to accomplish is making the pump work harder to move the same exact given volume of oil, not worth the time, risk of pump failure and added strain on the oil seals when the stock system works as it was designed.
 

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Discussion Starter · #12 ·

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Discussion Starter · #13 ·
I just measured the oil pump pick-up, pan and block.

From what I can tell, the screen on the pick-up sits 3/8 of an inch above the pick-up tube itself. The screen also sits 5 2/16 inches below the block. The pan is 6 1/16 deep where the screen sits. This means that the pick-up tube effectively sits 1 5/16 inches off of the bottom of the pan. This is substantially higher than the half-inch maximum the oil pan manufacturer that I talked with feels is acceptable.

Dale H
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Discussion Starter · #14 ·
Anyone care to crawl under their car and measure how far the oil pan could be dropped and still remain at or above the front cross member? From looking at http://www.cygnusx1.net/supra/gallery/oilpan_h.jpg it appears that the portion of the pan that surrounds the pump could be dropped another 2 inches or so without being exposed below the front cross member. Any help would be greatly appreciated!

Dale H
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Discussion Starter · #16 ·
MKNTRAXX,

That's a valid concern, however I'm just cutting and lowering the portion of the pan that clears (sits behind) the cross member. I just don't want to lower that part of the pan so much that it sits lower than the cross member and would be the first thing to drag if something were hit.

Thanks,
Dale
 
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Thank you for the links Faded87T.

This means that the pick-up tube effectively sits 1 5/16 inches off of the bottom of the pan.
Wow, are you sure? That sounds crazy high.

I have a factory "low oil" float switch, oil pan from an overseas Supra, that turns on a light when the oil drops too low, with the engine running.

When I purchased the unit, I could not believe how low the oil level sits with the engine running.

I will measure the height of it today, so we know how deep the oil is, and still considered normal.

I do not see a reason why we cannot easily run extra 2 liters (or more) of oil over stock, as even then it will not be anywhere close to getting "whipped up" by the crankshaft.

____

Bcastine, I agree with you, the stock oiling system works well. The only problem for me has been its sensitivity to low oil levels, wiping out bearings.

I wouldn't mind a little safety of margin, since our old cars inevitable leak. And it is fun to "tinker" with stuff, even though it isn't broken (yet). :)
 

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Discussion Starter · #18 ·
Shawndude (or anyone else.) If you could look at the way your oil pan sits in the car and measure how far the area at the very bottom (near the drain plug) could be lowered and not be exposed under the cross-member I would be very appreciative! I am going to try to drop the pan off to the shop on Monday.

Thanks!

Dale H
87T
 

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25psi = 14" brakes :)
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I always try and run over full, but not too much. (About 1/4 of the way more than the whole dipstick measurement.) So, my oil level is up near where the cable is clamped to the metal measurement part.
I have never had any issues with foaming, even accidently overfilled the car by a full quart once, drove for awhile, and then stopped to see if there was any foam on the dipsitck, none at all, and the level was over the top of the measurement part, and onto the cable barely.
I've never measured any of this, but it's interesting to see how much of a gap they left between the pan and the pickup. It would be easy to lower the pickup, and really solve the oil problem forever. (Or as is suggested, lower the pan too, and the pick up, and get even more capacity, but I'm not sure it's needed, just overfill your engine some.)
I'm going to add some oil to my leaky 88 right now:) LOL
BTW, I run a larger filter too, it just fits in the stock location, is a 3600 I think, and is about 2x longer than the stock one. No clearance issues, and I get better oil pressure due to more filter area and less backpressure. (Or something like that, I'm not sure, but the pressure is higher when I run the larger filters, and less when I don't.)
Also run full synthetic Mobil 1. Cheap insurance, and it leaks, but who cares, that is what old cardboard boxes are for:)
 

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Discussion Starter · #20 ·
Another interesting observation. If anyone has ever seen the baffling in a 7M oil pan, you can see that it looks like it would be quite effective at holding oil around the pick-up. The very bottom of the pan is surrounded by the baffle. If the pick-up tube were pushed all the way through this baffle it would be virtually impossible for oil to slosh around and escape the pick-up. I just measured the distance between the baffle and the bottom of the pan, and the baffle sits 1 and 5/8 inches off of the bottom of the pan. Using my previous measurements, that means that 1 and 5/16 of the 1 and 5/8 inch baffle is going unused. Looked at another way, the pick-up tube only sits 5/16 of an inch below the baffle. No wonder the baffling in a stock 7M oil pan appears to be inadequate.

Dale H
87T
 
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