motor help

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  • ohlde21
    Junior Member
    • May 2013
    • 11

    #1

    motor help

    I got a oil pressure issue on a fresh rebuild motor hold 60-70Psi cold and holds good until 220 degrees then oil pressure drops to 20-40 and bou. es back and forth like the motor starts cavatating and as soon as the motor drops back down to 200 the oil pressure goes right back up to 60psi what would cause this i change the oil and filter incase the filter pluged but the results were the same any ideas?
  • dereksehi
    Senior Member
    • Jun 2013
    • 307

    #2
    Is this at an idle or more rpm?

    Comment

    • ohlde21
      Junior Member
      • May 2013
      • 11

      #3
      This is at race rpm which is 6800-7100

      Comment

      • JustAddDirt
        Senior Member
        • May 2007
        • 1893

        #4
        do you have oil restrictors in the rear oil galley?
        what type of oil pan?
        What type of oil pump?
        I think there should be lifeguards in the genepool.

        Comment

        • ohlde21
          Junior Member
          • May 2013
          • 11

          #5
          7qt kick out with baffles... high volume pump ..... no on the rear galleys

          Comment

          • dereksehi
            Senior Member
            • Jun 2013
            • 307

            #6
            I would run the restrictors if it was mine sbc will pump an awful lot of oil up top if they are not restricted also was your pickup tube to bottom of oil pan clearance within the 1/4" to 3/8" tolerance?

            Comment

            • ohlde21
              Junior Member
              • May 2013
              • 11

              #7
              Yes the pump is a 1/4 inch off the bottom of the pan .. would windage cause this problem as well?

              Comment

              • JustAddDirt
                Senior Member
                • May 2007
                • 1893

                #8
                Are you running a roller camshaft and lifters, or is it a solid lift?
                Just checking, cause you may not want to run restrictors with a solid lift, or hydraulic camshaft.
                What happens if you add another quart of oil?
                What oil are you running?
                I think there should be lifeguards in the genepool.

                Comment

                • buzz51
                  Member
                  • May 2012
                  • 35

                  #9
                  Originally posted by JustAddDirt View Post
                  Are you running a roller camshaft and lifters, or is it a solid lift?
                  Just checking, cause you may not want to run restrictors with a solid lift, or hydraulic camshaft.
                  What happens if you add another quart of oil?
                  What oil are you running?
                  is this on the track when it happens or just in the shop ?

                  Comment

                  • powerslide
                    Senior Member
                    • May 2007
                    • 2696

                    #10
                    Originally posted by buzz51 View Post
                    is this on the track when it happens or just in the shop ?
                    exactly what i was wondering after re-reading his post a couple times.

                    Comment

                    • ohlde21
                      Junior Member
                      • May 2013
                      • 11

                      #11
                      Solid lift cam ..... this happened on the track

                      Comment

                      • buzz51
                        Member
                        • May 2012
                        • 35

                        #12
                        Originally posted by ohlde21 View Post
                        Solid lift cam ..... this happened on the track
                        ok thanks. I know on track I have had engine oil psi drop or bounce during the race due to oil being sloshed around and then as soon as the oil gets a chance to settle back in the the pan the psi went right back up.

                        another question please if you are at 220 and under caution does the oil psi drop or bounce ?

                        Comment

                        • ohlde21
                          Junior Member
                          • May 2013
                          • 11

                          #13
                          Under caution the pressure relaxes at 30 psi which i know is good and i know that 20 psi or lower for a long period of time leads to detination cuz thats what happen to the last motor on a hammer down tacky track

                          Comment

                          • JustAddDirt
                            Senior Member
                            • May 2007
                            • 1893

                            #14
                            What brand is the pan, and pickup? I have heard of this with cheap pans, and not many trap doors, and baffeling to control oil slosh.
                            Does the pan have trap doors around the pickup. if so how many?
                            How big of an area is the pickup in? If the pickup is a small one, and the area it is in the pan is pretty large, without trap doors or baffles, just wandering if the oil is moving around the pan a lot (as stated above), and sucking a bit of air.
                            I would try another quart or two and see if it fixes problem.
                            Of course oil will get hot, and thin out. What weight oil u running.
                            Remember the oil saying on oil PSI.
                            10psi for every 1k rpm's
                            Last edited by JustAddDirt; 06-05-2013, 08:43 AM.
                            I think there should be lifeguards in the genepool.

                            Comment

                            • buzz51
                              Member
                              • May 2012
                              • 35

                              #15
                              Originally posted by JustAddDirt View Post
                              What brand is the pan, and pickup? I have heard of this with cheap pans, and not many trap doors, and baffeling to control oil slosh.
                              Does the pan have trap doors around the pickup. if so how many?
                              How big of an area is the pickup in? If the pickup is a small one, and the area it is in the pan is pretty large, without trap doors or baffles, just wandering if the oil is moving around the pan a lot (as stated above), and sucking a bit of air.
                              I would try another quart or two and see if it fixes problem.
                              Of course oil will get hot, and thin out. What weight oil u running.
                              Remember the oil saying on oil PSI.
                              10psi for every 1k rpm's

                              all good stuff, what brand pan are you using.? Also just my two cents but what weight oil are you using..going to a straight 30wt should help psi as well.

                              Comment

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