Oil Pressure Equalization line

Discussion in 'Race 400/430/455' started by Jim Weise, Feb 24, 2015.

  1. Jim Weise

    Jim Weise EFI/DIS 482


    I am sorry to hear you had trouble..

    You said "all the bearings".. Main, rod and cam.. or just all the rod bearings.. or the mains and rods..

    Bearing caps blue?

    Pictures of the bearings might help.

    Normal autopsy should uncover the issues.. Main housings are the very first thing to look at when rod bearings fail. Contact the builder, and get the exact lubricant used and torque value for the girdle fasteners.

    Oil pressure during operation?

  2. buicksstage1

    buicksstage1 Well-Known Member

    Jim, It had a scavenger system on it?
  3. buicksstage1

    buicksstage1 Well-Known Member

    Like this?

    Attached Files:

  4. Jim Weise

    Jim Weise EFI/DIS 482

    If I built a kit with steel line, it would be either 5/16 or 3/8.

    I would test both.

  5. buicksstage1

    buicksstage1 Well-Known Member

    I guess what I am getting at is you know how some people would bypass at the back from pass side to drivers side? As you know there ain't much oil over on the drivers side and to me it seems that it would only bleed anything you had back there at the end of the oil curcuit on the pass side off to the drivers side and try to equilize over there there for taking oil away from the bottom end etc. Would you agree?
  6. Jim Weise

    Jim Weise EFI/DIS 482

    No idea what your talking about...

    whose doing anything with the driver side galley?

  7. buicksstage1

    buicksstage1 Well-Known Member

    It goes way back, I still get one from time to time that has it on there. I want to say it was a Jim B thing where they ran a line at the back from the drivers side to the pass side.
  8. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

  9. buicksstage1

    buicksstage1 Well-Known Member

    Thats the one thank you Larry. There would have no volume on that side and to me its just bleeding off oil from the back of the pass side oil passage. I want to do some testing at both those ports next time on the dyno for fun.
  10. m louk

    m louk Well-Known Member

    A long long time ago I had a engineer from GM tell me a good way to drop oil pressure was to run a line tying in the rear oil passages at the time I had a after market oil pump it had double the gears I also didn't know the shop that built the motor didn't blue print the motor. So tight bearings no rod side clearance to speak of. This was found on the tare down after several roll pins broke on the distributer gear. The last start up after replacing the roll pin a header tube started to turn cherry red. When we pulled the motor apart we found the front of the block at the cam was worn to the point it allowed the cam to walk back enough to hold one of the exhaust lifters open.A new KB oil pump and blue printed bottom end motor had good oil pressure 10 psi per 1k and no issues after 3 seasons of racing...........Mike
  11. Jim Weise

    Jim Weise EFI/DIS 482

    We don't have a volume issue with the TA pump housing and the 350 type pump cover. We are all working with the same iron blocks, modified similarly, and we have no problem filling the passages and creating pressure.

    Enough volume available for anything that does not need a dry sump, IMHO.. In fact, the only Buick 455 based engines I ever saw that had volume issues were the early big solid roller motors, that would expose the lifter galley when the lifter was up on the cam.. this was before we had fully shrouded solid roller lifters. Those motors had to have more volume, Sweesy's was like that, we had a hard time making 50 psi in that motor, when it was bleeding oil like that, even with a new TA cover. But that's not even an issue anymore, I built one in '13 that had a big solid roller in it, stock oil pump, and the fully shrouded lifters.. no issues.

    The Tomahawk blocks get away with much less pressure, and now that I hopefully have the program worked on on them, I expect to see a nice oil curve in the next one..

    I did run a similar setup on the first Tomahawk 555, just TA's version.. wish I would have just went internal oiling on that one. The scavenger type systems are bulky, big lines that are difficult to deal with in the vehicle..

    They certainly work, I just question whether they are required.

    The Supercharged 555 that will go together next month, will have the stock oil pump on it.. at hopefully well over 1000 HP..

    So I guess that is what I think of them..

  12. Jim Weise

    Jim Weise EFI/DIS 482

    Sure Chris, I never used that kit, I actually tied the lifter galleys together in the valley.. back in the 90's, before we had good cam bearings.

    I actually would put the front bearing in upside down, and block the LH galley passage up front, and just use the 1/8 steel line to feed the LH galley.

    Haven't done that mod since TA cam out with the first generation of back groove bearings, must have been about 97 or 98...

    It does not take that much to keep the LH galley full.. when we overhead oil the motors, we put pipe plugs in the front of the galley, (and deep in the rear of the RH galley, beyond the #5 feed) and drill 1 .060 hole to feed the lifters.

    Erickson's Tomahawk had .025 restrictors in it.. I have video of just how much oil will pass thru that small a hole, under pressure.

    HotRodRivi likes this.
  13. online170

    online170 Well-Known Member

    Cool writeup Jim.

    Somewhere over the years, i got the impression that the balance line only really started to work north of X-Rpm. Meaning you needed it if you were revving high, or you would run into trouble. I thought the number was 6500rpm.

    Probably not fair to ask to do a dyno test with/without to that RPM, as the results might be catastrophic. But i wonder if you would actually start to see pressure drop close to that RPM.

    For your pressure numbers, volumetric flow rate is the product of CrossSectional Area and Pressure. Im thinking its similar to a fuel pump. Free flow rate is always much higher than when under pressure. By removing restrictions and giving the oil an unrestricted shortcut, you are getting closer to free flow. But the volumetric flow rate is constant, so the pressure has to drop. My understanding of it anyway, i might be wrong.
  14. buicksstage1

    buicksstage1 Well-Known Member

    Been to 6700 and only saw a 6psi loss from front to back.
  15. buicksstage1

    buicksstage1 Well-Known Member

    The difference between the factory block needing more the higher pressure and the TA block not is because of the Priority main oiling, it doesn't require as much oil pressure to live. Friend of mine spins his windsor to 8000+ with maybe 50psi.

    I do wonder if Mike needs to look at using if possible a larger size pick up tube. All the oil pan builders seem to want a minimum AN12 line on the suction side to prevent pump cavitation. I wonder if the use of the heavier viscosity oil with these long smaller id pick up tubes aren't a problem. When I do mine I will most likey do a scavenger system with the external line to avoid that.
  16. online170

    online170 Well-Known Member


    For the 6700rpm pull, did the pressure ever drop on the respective end? ie; At the rear did the pressure ever drop as the RPM's climbed? Same for the front? 6psi seems to agree with the difference on Jim;s engine.
  17. buicksstage1

    buicksstage1 Well-Known Member

    No, held all the way. Front and back climb together. I intend on testing this as hp levels go up until I see a drop at the back. I am not trying to prove anyone wrong, I just need to know for my self instead of just doing it because someone said it works. Tom Rix came up with deal and he is a smart guy. A couple years ago when I was talking to Mike at AM&P we were talking about this line and I asked him if he ever tested with a gauge at the front and back to see what the difference in pressure was but most of all if it ever fell off and he said that no he hadn't and that he should of but never did so I decided at that point I needed to know if it worked and where the limits were. I am not one to take what someone else does as final word, I want to know where, when and why.
  18. gymracer01

    gymracer01 Well-Known Member


    Thanks for the reply. Yes the mains were bad, caps were not damage or blued and the cam bearings were only darken but not damaged. I'm sure all the torques were as recommended by TA. The engine was ran with the same oil I have used for years, Brad Penn. I was never to happy with the oil pressure. It varied a lot, but was at 70 psi crossing the finish line. One thing I was concerned about was the block had the lifter girdle and I was wondering about oil return because of limited drain back holes. I do believe the machine work (again done by a long time Buick shop) was correct and trust the man that assembled it. This engine was furnished as a sponsorship deal and I plan to repair it myself. But, I don't want to throw away money by not solving what kill it in the first place. Will be out of town a few days but when I return will get some pictures on. Thanks again for your time.

    Jim N.
  19. gymracer01

    gymracer01 Well-Known Member

    Buicksstage1, yes it does have that system but the pickup is on the driver's side and has the line to the rear of the block. It looks like a killer setup but with my problems and the success I have had with the stock system, makes me concerned to go back with it.

    Jim N.
  20. buicksstage1

    buicksstage1 Well-Known Member

    Why is the pick up on the drivers side? Seems to me that would not be a great idea having all the extra line etc. Is it a AN12 on the suction side?

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