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Thread: 3sge beams blacktop high oil pressure

  1. #1
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    Default 3sge beams blacktop high oil pressure

    Hi all,

    First off, a quick “hi” from me, new to this forum.

    I’ve got a race-spec Lotus Seven replica (RAW Striker) with a very recently installed Altezza RS200 3sge beams blacktop.

    We’re however having issues with high oil pressure. The engine has a dry-sump with a custom ali sump pan making use of the original internal Toyota pump, relief valve and filter. The filter has a sandwich plate feeding to an oil cooler with a valve for it to be by-passed when cold. A two-stage pump is used for scavenging back to the 8-litre dry-sump tank. Between the Toyota oil pump and relief valve, there is a pickup for an oil sensor (so it’s measuring in the pressurised line).

    Upon the first run of the engine (a few weeks back), oil pressure was at normal levels. Since then we removed the pan to make a small adjustment and changed from mineral oil (for the first in situ start) to 5w50 full-synthetic oil. Upon the first start with the new oil it was registering 8 bar (115 psi) at idle. This was too much for the digital sensor installed, so we temporarily moved over to an analogue gauge. When revving the engine, it disappeared off the gauge, but reached an estimated 11 bar (160 psi). Oil tempteratures at idle were around 70 degrees C.

    We dismantled the lot again and found nothing untoward. We also replaced the filter, being sure to replace with an OEM version. Cutting open the ‘old’ filter revealed nothing. Dismantling the relief valve also revealed nothing. After re-assembling, it dropped to a healthier 4.5 bar (65 psi) at idle, revving up to 8 bar (115 psi). 30 minutes idling and no problems. However the next day on the circuit the digital sensor was reporting an error, which makes us assume the pressure was once again above 7 bar (100 psi). Oil temp was at around 100 degrees, a little cooler than we'd ideally like but no major issue. No further diagnosis has as yet happened (that was only yesterday!).

    We’re totally at a loss as to what could cause the high pressure. The pressurised part of the system makes use of only original parts that have previously worked, so it would seem strange that this should happen.

    Has anybody got any ideas or advice? As far as I can tell from limited information on standard road cars, the pressure should be around 2 bar at idle, 6 bar under load. The engine seems to perform correctly in the handful of laps we did before we stopped running, however we’re not happy with these numbers.

    Also, if you happen to have one of these engines in a non-standard setup, I would love to hear what your pressure readings are (and where you measure them!).

    Thanks in advance for any help!!

    Cheers,

    Jon.
    Last edited by JonT; 15-08-2011 at 11:22 PM.

  2. #2
    Junior Member Automotive Encyclopaedia
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    Default Re: 3sge beams blacktop high oil pressure

    the normal place for the stock oil pressure unit is off the top of the cylinder head.

    i'm not goin to pretend i know anything, but to me i'd have thought you want the sender unit to measure somewhere in the oil system after the relief valve. i may have got mixed up with which relief valve it's currently between, the stock oil pressure relief valve or the bypass for the oil cooler?

    which of these did you check/reassemble?

  3. #3
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    Default Re: 3sge beams blacktop high oil pressure

    Hi Jonathan,

    Thanks for the response.

    The pressure sensor is in between the stock pump and oil pressure relief valve (which is what was checked/reassembled).

    The oil cooler valve wasn't checked, as it shouldn't have a derogatory effect on pressure. I'm thinking we should lose the cooler altogether and see if it makes a difference.

    You're saying the sensor is normally placed in the top of the cylinder head, do you have an idea where that is? We see one logical place for a sensor, but it's worth asking

  4. #4
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    Default Re: 3sge beams blacktop high oil pressure

    black tops can be any where from 100 kph to over 700 at full load ,your relief valve for the oil cooler could be causing you problems
    i still run my beams with a wet sump set up and im reving mine to 9000 rpm ,but im also using forged rods and pistons and also quad throttle and 2 stage injection as well
    oil pressure is from a std mechaical guage taken from the altezza sump near the std oil filter

    are you still using the vvti system at all

  5. #5
    Junior Member Backyard Mechanic
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    Default Re: 3sge beams blacktop high oil pressure

    theres a fella down here in tasmania running a dry sumped 3sgte in his ae86 illl tell him about this

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    Default Re: 3sge beams blacktop high oil pressure

    @CelicaRA45:
    100 – 700 kpa, that converts to 1 – 7 bar. That’s about in line with what I’m hearing. It seems strange to us that the oil cooler valve could be causing these issues as it will be closed off during cold running, yet the pressure immediately starts high. I think we can best drop it out and see if that makes a difference, then at least we have our answer.
    The reasoning for the dry-sump is twofold: firstly we need the vertical space as the engine bay is quite small. Secondly, it’s in a race setting on circuits with long, fast corners so a good idea anyway, extra complexities and all.
    Yes, we’re using the vvti system, also with standard ECU.
    Â*
    @skin: thanks, that would be great.

  7. #7
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    Default Re: 3sge beams blacktop high oil pressure

    my race car with wet sump 1.5 G through corners on a semi slick tyres ,the only trouble with dry sump it seems to cause friction which inturn cause higher oil temps ,

  8. #8
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    Default Re: 3sge beams blacktop high oil pressure

    the only real possible way for the oil pressure to be too high is for the relief valve to be sticking or jamming, this is commonly from a damaged housing.. if it was always too high then a lighter spring pressure could rectify the issue, or maybe a bigger pressure bleed hole coming out of the relief valve area.. 100psi is still too high imo, its wasting power to create that much pressure and it could damage your bearings... 75psi would be more than enough..
    alternativly change to a 3 stage external pump for ease of pressure adjustment and gearing change
    Owner built, tuned and driven. 420kw 9000rpm 3sGTE AE86 Levin

  9. #9
    teq Grease Monkey
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    Default Re: 3sge beams blacktop high oil pressure

    5W-50 is too thick for the motor IIRC. I'm running either 0w-30 or 5w-30 in mine (CRS just kicked in).

    Andrew

  10. #10
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    Default Re: 3sge beams blacktop high oil pressure

    the black top beams always has over 100 psi as it needs this pressure for the dual vvti
    and im using 5 w 60 super syn penrite also good for ethenol fuel as well

  11. #11
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    Default Re: 3sge beams blacktop high oil pressure

    @CelicaRA45:
    We need the dry-sump at any rate due to height issues and have an oil cooler to deal with temperature issues, so should be ok.
    If the beams always needs 100 psi minimum for the vvti, would that not imply that the scaling for the standard gauge is incorrect? If you’re already starting at 7 bar, then it would almost be off the scale, surely?? Or is it a case of only needing the pressure for above 5k revs when the vvti kicks in?
    Â*
    @s14seriesII:
    then I guess we will have to check the relief valve again. Being as we have the stock pump, there shoudnt be a need to have to change the specs of the valve. A change to an external pump is always an option of course, but I think thats more symptom-solving. There shouldnt be a reason why the standard system shouldnt work this way. All good in theory, I guess!
    Â*
    At any rate I now see the following two things we can check:
    1. double-check the relief valve
    2. run without the oil cooler (valve) and observe any differences
    3. measure oil pressure in the head instead of between pump and relief valve
    Â*
    Thanks for the support, guys. We'll try this and report back.

  12. #12
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    Default Re: 3sge beams blacktop high oil pressure

    vvti is working from start up and is always on changing lobe centers ,it isnt like vtec and kicks in at high rpm

  13. #13
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    Default Re: 3sge beams blacktop high oil pressure

    Quote Originally Posted by JonT View Post
    @CelicaRA45:
    Or is it a case of only needing the pressure for above 5k revs when the vvti kicks in?

    3. measure oil pressure in the head instead of between pump and relief valve
    As Glen/Celica RA45 said, VVT-i is working right from idle all the way to redline.


    You should be measuring galley pressure AFTER the relief valve. Measuring in front of it could give you a false reading to what is actually reaching the mains.

    Andrew

  14. #14
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    Default Re: 3sge beams blacktop high oil pressure

    Hi all,

    Ok, we've been busy...but I think we may have got somewhere...and nowhere, actually, as it happens!

    Changed the oil to 5w30 and no change.
    Dropped the oil cooler out and also no change.

    So we then moved the sensor to after the relief valve, tapped into the cooler housing just before the filter, so as similar to original spec. as possible...and the sensor returned 'ERROR', concluding it was above 10 bar (145 psi). We then connected an old calibrated analogue meter to see if it was the sensor...and bingo! The reading was 5.8 bar (85 psi) on cold idle (900 rpm). Conclusion: sensor broke.

    So that would match up with the theory of high pressure for vvt-i...and it would appear we've solved the problem of having no problem?!

    Thanks to you all for the info, I'm sure it's not the end of it all, but it looks good for now.

    At any rate I have another issue to deal with concerning throttle response, but that will come another time

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