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


    No, never tested with those parameters. Simply because it never came up. 6500+ rpm Iron block motors are not that common, much less so now with the advent of the TA block. I do have one in the shop now, owned by a local guy named Kurt.. it made 700 HP with a nearly stock TA SP-2 on it, I may use that motor to test the intake that is being welded up right now, for Mike Erickson's Tomahawk.

    That motor does have the equalization line, we could test that one also. With the bigger race motor clearances in that motor, it may have more of an influence on oil pressure. No worries about hurting it, we will always monitor the pressure on the rear, and if it went below 60psi I would abort the pull.
  2. Jim Weise

    Jim Weise EFI/DIS 482


    Is the block filled in the valley, or does it have the TA lifter bore girdle? If it is filled in the valley, then yes, all kinds of bad things can happen.

    My advice... I am not a fan of a devcon filled valley.. too many bad side effects.. you must have at least 1 -8 oil return line from the back of the each head to the oil pan, at least that is my understanding. If it has the TA lifter bore girdle in it, then oil return has not been affected.

    I would go back to the standard oiling system, with an internal pickup if you can, use a 350 style pump cover on a TA timing cover, and you will be fine.

    Oil pressure gauges lie.. Chris called Autometer the other day, and was told they have a restriction in them to dampen the needle fluctuations, and come to think of it, I have seen that.. IMHO, only the pressure transducers on a dyno or data acquisition system can be counted on for reliable testing information.

    Chris, I never had good luck on high volume demand motors with an -12 AN feed line. I do -16 now. Issue is the fitting size restrictions. -12 hose itself is plenty big enough, but the -12 AN fittings/adapters are small.. 5/8 or thereabouts minimum restriction size, as I recall. I even went to Steel Aeroquip industrial stuff, but still too small. My opinion is that if the motor works with a -12 pickup, it does not need an external pickup/scavenger system at all.

    I have the one of the prototype SRE pickup tubes for the Tomahawk, it's 7/8" in Diam. It's big..


    You would never tie to the driver side galley, the mains of a 455 are fed off the passenger side only. Years ago we had a problem with cam bearings, and we would put a small line between the two galleys, but that has been done away with now, with the TA cam bearings.

  3. buicksstage1

    buicksstage1 Well-Known Member

    I agree, if you can get a -12 equivalent oil pick up tube then yes I would most likely use that. -12 pick up line is what AM&P sells in there scavenger kit and that is the ID of the SRE pick up but yes I think it should be a minimum -14.

    Its not that the oil gauge lies, they are actually accurate, they just put the restriction in the gauge to kill the sensitivity of the gauge/needle. I had 2 Auto Meter gauges hooked up to the front and back and the dyno gauge was T'd into the back but they all show the drop. Even with the O/P in the 40's at the back, messing with adding, removing oil, I even stood next to it with a pen light in the valve cover watching for air bubbles in the oil I pulled it apart after all that abuse and the bearings were still like new.
  4. gymracer01

    gymracer01 Well-Known Member


    Again, thaks so much for your time. Yes it has the SRE pickup. It also has the filler lifter valley. I think oil return is the problem.. I think I'm going back the the setup like you said. The machinist that I'm having do the crank suggest that. Different guy but he has done too engine machine work and every clearance is dead on. Will get some pictures and more info when I return home.

    Thaks so much,

    Jim N.
  5. Steve Reynolds

    Steve Reynolds SRE Inc

    Jim, what size pickup do you have .. the -12 or -16? I always try to recommend the -16 ever since Peterson Fluids told me of their theories and experiences with larger vs. smaller sized pickups. Some people decide on the -12 because they feel there is not enough room for the larger fittings with the -16. I've always used -16 on my stuff and I've never had a problem with any oil related failures. On my 523 I do have restrictors at the end of my pushrods to limit the oil volume up on top. I also run a MasterLube oil system which I consider very cheap insurance to keep constant oil pressure in the engine and to help these things survive! I would never run a drag car without this in place.

  6. Thumper (aka greatscat)

    Thumper (aka greatscat) Well-Known Member

    Hey Steve
    Where did you get your masterlube? What do you think of the Canton or Moroso systems?
  7. gymracer01

    gymracer01 Well-Known Member

    Steve, it had the 16. Don't think that is the problem.

    Jim N.
  8. gymracer01

    gymracer01 Well-Known Member


    I was wrong and brain dead. The pickup is on passengers side of pan. Checked pics in phone. Guess I had looked at it on engine stand upside down so much I was screwed up. And again the pickup was 16...same size as SRE pickup. I just know the machine work and assemble was correct, something happened in the oiling.

    Jim N.
  9. buicksstage1

    buicksstage1 Well-Known Member

    Steve, have you changed the pick up size since both my pans were done?
  10. Steve Reynolds

    Steve Reynolds SRE Inc

    I bought my MasterLube unit directly from MasterLube. At one time I thought of being a distributor for them, but I just never pursued it. The Moroso and Canton units are good and certainly better than not running any, but I prefer the MasterLube for several reasons, simpler, lighter, no piston or diaphragm, etc.

    I'm not following your question. Do you mean internal or external pickups?
    What I can tell you about my Oil Pickups;

    SRE stock block internal pickups have always been made with 3/4" OD x .060" wall mechanical tubing.

    The Tomahawk internal oil pickup is made from 7/8" OD x .060" wall mechanical tubing.

    External pickups are available with -12 or -16 AN size. I rarely sell the -12 anymore. Most choose the -16 and that's been my recommendation for at least 10 years now.
  11. No Lift

    No Lift Platinum Level Contributor

    Jim, what do you mean by the "350 type pump cover"? If you are talking about the oil filter adapter/pump cover which one are you favoring? I always figured they were all the same, 350/455, of course those are the post 1970 with larger passages. I know there are some different V6 ones also. Maybe I missed something along the line.
  12. Thumper (aka greatscat)

    Thumper (aka greatscat) Well-Known Member

  13. sailbrd

    sailbrd Well-Known Member

    I want to know too.
  14. Jim Weise

    Jim Weise EFI/DIS 482

    Hi Guys..

    Sorry, that's my slang for the new replacement oil pump covers.. I call them the 350 cover..

    This one..


    they take less work to get good flow out of, vs the oe 455 style cover, which are getting scarce anyway..

  15. Dave Mongeon

    Dave Mongeon Well-Known Member

    IMG_20150302_182802.jpg IMG_20150302_182824.jpg IMG_20150302_182831.jpg
    When we started doing this in the old days, we used to run 1/2" stainless tube. drill and tap the two stand offs
    notch the back of the block and tuck it up under the headers . most people didn't notice it was even there. I think
    Charlie Evens, was the first one to say something about it. We made it 1/2" cuz we wanted more volume back there.
    At the time we used to drill the block 1/2" front to back and made every oil passage in the delivery system at least
    1/2"dia. This was fine for flat tappets but just caused more hemorrhaging with the rollers available at the time .
    If your going to test try the 1\2" and try checking pressure inside the pump! Thats what spawned the first "scavenger'
    that pegged a 200lb oil psi guage warming up in the pits!

  16. Dave Mongeon

    Dave Mongeon Well-Known Member

  17. gymracer01

    gymracer01 Well-Known Member


    More on my bearing problem, did look at it some more. No bluing on caps or block. As for the oil return that I'm concerned about. He has two line in the back of the block running down the outside of the engine behind the flywheel and in to the crankcase on each side of the rear main. One is 3/8" and the other 5/16". I'm concerned that is not enough. I may have killed it by too much oil staying in the top end. Do not have restricted pushrods. It had all the mods that has been talked about on the web. Very nice knife edged crank and radius oil holes and the good mains. Want to fix this as the block has lots of work in it. But for sure don't want to lose it again.

    Jim N.

    P.S. There are also 4 brass nipples in the bottom of the valley I guess to lube cam but they stick up 3/4" and only have about 5/16" hole.
  18. Steve Reynolds

    Steve Reynolds SRE Inc

    As long as you have the engine apart you can do like Mike did on mine. Silver solder one end of the pushrod shut and then drill a small hole with a pin vise. I'm not sure without looking on my build sheet, but I think it's .030 or less. Call Mike Phillips and ask him to be certain. Works great and eliminates the need for custom pushrods.
  19. Jim Weise

    Jim Weise EFI/DIS 482


    The Brass "nipples" or standpipes, are used to assist getting the crankcase pressure to the breathers in the top of the engine.

    I never ran a filled valley block in racing applications, so I have no first hand knowledge of exactly what size return lines from the heads are required. I thought I had heard guys having success with 1/2 inch (#8) in the rear of each head.

    I did consider doing this, and one thing I was going to do is block the normal return passages in the heads, to make all the oil return via the "new return path" with the line. While block standpipes level with the fill will help minimize oil trapped in the valley, it will increase the amount of oil there, no doubt.. your taking a "V" and putting a flat floor on it with the fill.

    Limiting upper end oil volume to the absolute minimum required would be critical to the success of this mod, along with a substantial increase in sump volume in the oil pan. Keep in mind that reduction in oil to the upper end will decrease, to some extent, valve spring life, so keep an eye on them.

    Technically speaking, reduction of windage by re-routing the oil return away from the spinning crank, should result in more useable HP, especially in a race engine at higher rpm.

    You just have to keep it alive..

    I would build it, and dyno it, to observe oil pressure with transducers, and then verify "good" dyno results with a physical bearing inspection, before that engine got anywhere near a race car again.

  20. TheSilverBuick

    TheSilverBuick In the Middle of No Where

    As a tidbit that may or may not be relevant, but I know folks out Bonneville Salt Flat Landspeed racing have ran into oil return issues (think 90 seconds of the engine at high'ish rpm and loaded up) where the blow-by gasses racing upwards to vent at the valve covers prevented the oil from returning efficiently to the pan. A solution implemented was turning the mechanical pump block off plate into a baffled vent, which allowed the gasses to go out that way and the oil to drop down the normal paths. It was an unusual problem to say the least. This was on a pair of big block Chevy's with some boost applied and clearing well over 200mph.

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