Higher oil PSI?
- Thread starter mmarchmonte88
- Start date
Also it's best to replace the squirters bolts. They lose tension over time and start opening very early.
3p141592654;2041058 said:
That is so true. When doing my rebuild tested 18 old squirter bolts. 4 bolts where open all the time (bye bye ilde oil pressure). 8 bolts opened on very low pressure. 3 bolts stuck open sometimes. Only 3 bolts where quite good.
Springs tend to slacken over time and metal particles can cause the ball to seize.
My own opinion is that 7M has a bit troublesome oiling system in stock form. When you use good oil and have enough of it most likely you dont have any problems (If your power level is near stock). BUT when the engine is hot and the oil is hot on stock setup the idle oil pressure is too low (in my opinion).
I have rebuild several 7M engines and noticed that often the valve train has quite a bit of wear that is most likely cause by lack of oil. My first supra back in 1996 was driven mostly on city trafic by it's previous owner and it had very bad valve train wear when I bought it. The car was always serviced in time and in Toyota dealer by previous owner so no user error there. Later I have noticed the same issue in many 7M engines that I have been working on. I never had any issues on bottom end wear on 7M.
In my current build I'm going to chage the oilpump speed so can get more pressure. Going to use 4e-fe cam gear that has 42 teeth. The stock oil pump gear has 46 so the diferance is not that big but should give more idle pressure. Also I'm not going to use that crappy stock oil filter bracket. It has a very very bad desing. The pressure dependent cooler circulation is a joke. You can get more oil pressure just by removing the stock bracket. I'm using Mocal thermostat housing and AN10 lines from that to cooler.
There are few monster 7M engines here in Finland that have modified oil pump speed. Jusbas 1200hp uses 36 teeth gear on oil pump but thats a bit extreme for my build. There has also been some talk around the stock hardline from oil pump to block. Jusbas 1200hp engine uses the stock line. The stock banjo bolt is the most restrictive part there. You can drill the bolt holes (the 4 small holes on side) bit bigger or find a bolt that has bigger holes. I drilled mine so that the 4 small holes have the same combined surface area as the big center hole......hope you understand what I'm trying to say.:biglaugh:
Also shimmed my oil pump relief valve by 5mm. Using a new OEM pump. And did some modification for oil pan.
All the mods are done so I can have a peace of mind. :biglaugh:
fromgehenna;2041178 said:
How much more oil flow do you think you need? Do you understand that the oil at 210 degrees has the properties that are desired, and not when it is 40 degrees?
Did you catch the comment about it is a relief valve and has nothing to do with idle flow?
As a side note, I was watching Motor Week last Sunday on the DVR. Same two guys after all this time. They were telling about the stock oil spec on the car in the garage of 5 psi and full flow of 45-75 psi (one model is a turbo car). I laughed.
Nick M;2041180 said:
Did I say that I shimmed it for more idle pressure?? :nono: No I did not. At that point of my text I was just writing what mod's I did for my oil system. Was I writing something of idle pressure in that sentence?? No I was not.:biglaugh:
Well the oil has good properties at 210 degree of fahrenheit but if the pressure is low......... well it's low and if it's too low then it does not matter what the properties are if there is not enough oil film between metal surfaces.
fromgehenna;2041219 said:
You sure did. Right here.
You lamented the stock oil pressure at idle, then you said how you were going to raise it.
It is best if you just don't comment about oil. Since you know more about it than the API, SAE who developed the rating, GM, Ford, Toyota, Honda, etc etc in regards to properties at operating temps.
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Nick M;2041180 said:
I don't know about him (and didn't read pump was shimed for idle pressure), but ratings are nothing if you don't know the specific clearances.
I built my 7M in the high clearance specs, and need xxW40 or even 50 to achieve 0.8 bars at idle, and 0.8 bars more each 1000 rpm steps.
I wish I had shimed my pump because my pressure tops off too low on top for my taste.
Rollus;2041277 said:
So you installed oil that doesn't flow as well hot? What you really needed if you opened up the clearances (why?) is pump more oil. That give you higher
"psi" on your gauge because more oil is trying to occupy the same space.
I probably mispell my sentence or didn't understood your first question..
I built my 7M in the high clearance specs, and need xxW40 or even 50 to achieve 0.8 bars at HOT idle, and 0.8 bars more each 1000 rpm steps. These 0.8 bars (11.6 PSI) are fine to me.
I opened the clearance using standard Clevites. That's not really a choice. BTW I don't mind because my engine is forged, 9.5:1 CR, E85, with a power goal @ 500hp, that will be growing with gearbox upgrades..
If I achieve a good pressure at low-mid rpm, I can't understand how pumping more oil would increase top pressure, I guess I have a problem with a relief valve somewhere. Our pumps are volumetric, not centrifugal.
If I unerstand you, I could close a little my pumps clearance (but already in the low spec), or make it spin faster. Then if I don't want too much pressure (what is too much?) at idle or low rpm, I would have to increase viscosity (..W30? 40), and then, what about top pressure? That's vicious. I probably just have to check my oil system, maybe the pump pressure valve isn't correctly installed (I didn't change the pump, it has 12000km and passed TSRM checks)
I built my 7M in the high clearance specs, and need xxW40 or even 50 to achieve 0.8 bars at HOT idle, and 0.8 bars more each 1000 rpm steps. These 0.8 bars (11.6 PSI) are fine to me.
I opened the clearance using standard Clevites. That's not really a choice. BTW I don't mind because my engine is forged, 9.5:1 CR, E85, with a power goal @ 500hp, that will be growing with gearbox upgrades..
If I achieve a good pressure at low-mid rpm, I can't understand how pumping more oil would increase top pressure, I guess I have a problem with a relief valve somewhere. Our pumps are volumetric, not centrifugal.
If I unerstand you, I could close a little my pumps clearance (but already in the low spec), or make it spin faster. Then if I don't want too much pressure (what is too much?) at idle or low rpm, I would have to increase viscosity (..W30? 40), and then, what about top pressure? That's vicious. I probably just have to check my oil system, maybe the pump pressure valve isn't correctly installed (I didn't change the pump, it has 12000km and passed TSRM checks)
My recently acquired ride pegs oil pressure at about 30psi by 2krpm but does not go above this ever.... not even when cold (on a real aftermarket gauge). Idle is about 4-6psi warm with 10w30. I think I have lazy squirters or something... really bothers me actually. My saab runs like 30psi at idle and near 80 at cruise. i know everyone says it's supposed to run low but I'm tempted to remove the pan and replace everything before i even drive it.... I've seen mixed opinions on this but is it acceptable to just delete the squirters with forged pistons??
I'd check the cooler bypass before pulling apart the engine. Can't think of too many factory performance engines without squirters.
mrgibs121;2041734 said:
First off: before doing anything to change your pressure "problem" you should test it with a known good gauge. The factory gauge is worthless for diagnostics.
You can replace the squirters for $70 or so. Is it acceptable to delete them? I guess. I would never do that though. The engine won't die right away, but you'll be more likely to have problems. If you're making enough power for your slightly low oil pressure to be a concern you would also probably benefit from the squirters and should certainly be happy to pay $70 for oil squirters.
Even weak oil squirters are probably doing you more favors than the extra pressure from deleting them would do.
If you're anywhere around stock power most of this thread is pointless. The stock system has worked well for many owners, including me for over 25k miles/5 years at 10-12psi on a 50 trim CT26. If you're way over that power level then I suppose altering the system to provide more pressure *may* help, but people are overly concerned about the pressure issue on sub 450whp 7Ms.
3p141592654;2041736 said:
These readings are from an autometer phantom gauge. I did that first and foremost because i knew the stock one was crap. Its converted to a full flow thermostated system so it cant be the bypass
suprarx7nut;2041755 said:
Ok so keep the squirters. Ill just get new ones then. I read a few threads with people deleting them and saying it was fine but this hasn't even be a discussion on other cars i've owned so its new to to me. Im just worried about killing another turbo. The GT4088 was new when the PO rebuilt the engine 3k miles ago and already needs to be replaced or rebuilt (exhaust seal is gone, wheel touched the housing a little, thrust bearing play). I guess I'm maybe overthinking things but that turbo died for a reason.... otherwise the engine acts and sounds very healthy. Im already set up for about 400whp, just need to fix the turbo and drive it for a few weeks before I start increasing boost. Are there any other controlled pressure releases that I'm missing? like I said it's very consistent at 30psi.
Reliefs: oil pump, stock oil filter adapter, oil filter itself, squirters.
Exit points: cams, crank, rods, turbo
Exit points: cams, crank, rods, turbo
That would not be correct. The block I am referring to was a JDM turbo motor. number on block matches a turbo. No GE-T conversion that's why I posted the difference between GTEs with and w/o oil squirts.3p141592654;2040670 said:
My comment was to USDM. The EPM shows squirters on all years starting 87 which was first year of turbo option.
15708-42010 Supra (NATO) 08/1986 - 08/1988 7MGTE..MA70
For non-NATO markets it looks like squirters were not used for man dates of 08/1986 - 07/1987 which would seem to align with your experience.
15708-42010 Supra 08/1987 - 08/1988 7MGTE..MA70
15708-42010 Supra 08/1988 - 05/1993 7MGTE..MA70
As noted earlier, turbo blocks have a taller oil pump.
15100-42020 Supra 08/1987 - 08/1988 7MGTE..MA70
15100-42030 Supra 01/1986 - 08/1988 7MGE..MA70
15708-42010 Supra (NATO) 08/1986 - 08/1988 7MGTE..MA70
For non-NATO markets it looks like squirters were not used for man dates of 08/1986 - 07/1987 which would seem to align with your experience.
15708-42010 Supra 08/1987 - 08/1988 7MGTE..MA70
15708-42010 Supra 08/1988 - 05/1993 7MGTE..MA70
As noted earlier, turbo blocks have a taller oil pump.
15100-42020 Supra 08/1987 - 08/1988 7MGTE..MA70
15100-42030 Supra 01/1986 - 08/1988 7MGE..MA70