Got a Oil pressure problem, kinda long.

Discussion in 'Troubleshooting & Diagnosis' started by Old School, Feb 14, 2003.

  1. Old School

    Old School Veteran Member

    1,954
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    Jul 8, 2001
    Arlington, TX
    I don't know what the clearences were, my builder did say he didn't see anything that looked bad that would cause what I said was my problem(psi drop). Like I said before, this motor is coming out onemore time and its for good. I got plans for a 408 to replace it, so I got something to look forward to. hehehe

    Michael
     
  2. EddieF

    EddieF New Member

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    May 5, 2003
    staten island, new york
    Do us this favor...when the time comes and ya pull it, disassemble it for us takin pictures of everything. Plastigauge every single rod and main bearing. Also the thrust clearance with feeler gauge. You'll help us out alot with future projects.
     
  3. Old School

    Old School Veteran Member

    1,954
    0
    Jul 8, 2001
    Arlington, TX
    I got a friend (jakeshoe) thats gonna help me do somethings with this whole engine and I'm sure he will do all the checking there is to figure out whats wrong with it.

    Michael
     
  4. MrAzzhat2U

    MrAzzhat2U Veteran Member Lifetime Gold Member

    1,392
    6
    Jan 31, 2000
    Lewes DE
    Once again I have to agree with jakeshoe(even though Seals are better than Rangers,NBL!)If the cam was not broken in properly from the get go it will continually wear the cam bearings till it seeks its total amount of movement!This is a common problem with most engines.
    The quickest way to check for too much movement is with a good vacuum gauge.Tape it to the windshield and drive the vehicle,watch for a flutter in the gauge on accel or decel.If you see any abnormal movement in the gauge there is your problem.Also,if the cam bearings aren't in the exact position they are suppose to be in,you will get the same result.Someone mentioned a cam button,that would prove out the theory of excessive cam movement.
    You ask how do I know this?Over thirty years as an ASE master tech and have made this mistake before.I would be very suprised if this is not your problem.Let us know what you come up with!

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    79Z(SUESZ) 91Z(SUESZII)
    79Z Rough 82SC(Son's)
    73Z RS/LT Really Rough
    99Z28 LS1 6spd.
     
  5. jakeshoe

    jakeshoe Veteran Member Lifetime Gold Member

    8,856
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    Dec 8, 2000
    Republic of Texas
    I'll add something else to this post for Eric with BBC.
    BE SURE you hone the lifter bores on your motor. Check lifter for ANY binding in the bore.
    Be sure the lifter spins once you get the motor running by watching pushrod rotation.
    With a hydraulic you should have a fairly constant even rotation.
    With a solid you will have an uneven rotation as the lifter hits the lash it will slow down, then spin faster as it gets back into the lobe.
    BBC's are prone to camshaft failure because of higher spring pressures, more rocker ratio, and the oil drainback isn't adequate lube at low rpms.
    Solid lifter cam actually lasts longer in this type of application. A GREAT thing to do on these is to use the solids with laser cut hole in the bottom.
     
  6. maledoggy

    maledoggy Member

    93
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    Jun 30, 2002
    chicago
    hey bud we chatted a while back. my motor was doing the same thing so i pulled it, took it back to the machine shop they checked it out - all was ok. i told them to replace the oil pump with a system 1 oil pump,and to put in a windage tray. i also replaced my new hei with a msd set up.
    and my oil problem is gone.. not sure which of the 3 things fixed it ,but its fixed i hope this helps you out



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  7. Old School

    Old School Veteran Member

    1,954
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    Jul 8, 2001
    Arlington, TX
    Well, here's a doosey for you guys, I took the camaro over to Jake's house (jakeshoe) and just for the hell of it I took him around the block to let him see how the oil psi was doing. And wouldn't you know it, the problem isn't there anymore?????? I must have ran it 6 times for him and another 3 times when I was headed home and it never did drop like before. It would go down alittle to about 55ish and then back up. Jake saw and I think he thought I had been lieing this whole time about the problem. lol I'm stumped, maybe something was clooged and finally came loose?? The problem started when the pick-up screen broke off and the little wires got in the filter, well maybe one little one never got to the filter and maybe thats what work its way loose. My builder should have gone through the motor to make sure it was clear, dunno, but for now, I am going to take it to the track and go at it and see how she does.

    Kets hear some theories on this!!!

    Michael
     
  8. madalo

    madalo Veteran Member

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    Jan 2, 2003
    San Diego, CA, USA
    this may be a little late but did you make sure the 1/2" plug under the rear main cap was installed right? its a thin stamped plug and its worth about 25psi due to a lot of oil going back instead of to the rest of the engine
     
  9. Victor1969

    Victor1969 New Member

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    Jun 8, 2003
    Thomasville,Ga. USA
    I had the same problem with my engine so I have read this thread from one end to the other. I have a 1969 Corvette with a 350 stroked to a 383.Hot idle about 20...cruise about 60...but at 4500 RPM and up the pressure would fluctuate and fall back to 30 and would keep falling unless I backed off.As soon as I drop the speed back down the pressure would go back up. I solved the problem....here's what I did.

    1 - Installed a crankshaft scraper
    2 - Replaced the oil pump...the old pump was a Melling M55A standard volume/high pressure which showed absolutely no wear(4000 miles).The new pump is another M55A..I changed it just because I was in the engine anyway.
    3 - Replaced the oil pick-up...stock design just like the old one. I moved it up to 1/4 inch off the pan...the old one was about 1/8 inch off.
    4 - Installed a windage baffle. This is what I think solved the problem. The crank journal with rods 5 and 6 on it is right over the pick-up. The extra stroke brought the rods just a little closer to the oil than the stock crank. In my case 4 quarts of oil brought the oil level to about 1 inch from the rods with nothing to stop the oil from being whipped around.

    I don't know if the condition existed before I installed a longer stroke crank.

    I'm a happy dude now... 6000 RPM - 70 PSI and steady.
     
  10. Old School

    Old School Veteran Member

    1,954
    0
    Jul 8, 2001
    Arlington, TX
    Thanks Victor for the input. We were you about 6 months ago when the problem started?? Heck, I spent plenty of time and money tryin to fix the problem. lol

    Michael
     

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