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  1. #1

    Default Reversed the reverse, changed the oil pump and now no fire.

    I took a 350sbc cris craft reverse engine, changed it into a standard rotation and it ran great. I didnt like the low oil pressure so i installed a new oil pump. When cranking, the gauge now shows good pressure but now it will not start... backfires every now and then but no start whatsoever.

    The ONLY thing I changed was the oil pump, so I suspect the problem must be there. Is the oil pump geared differently on the reverse rotation engines? I have checked and rechecked the firing order and timing, and found it to be correct. What would be different between the original oil pump that was installed on the reverse rotation, and a new oil pump that is for standard rotation?

    Logic tells me that since it was running fine in the new standard rotation mode with the original pump, the pump is not the issue, but I keep going back to the fact that the only thing I changed was the pump and now it will not start. Any ideas?

  2. #2
    Join Date
    Mar 2009
    Location
    Portland, Oregon,
    Posts
    12,001

    Default Re: Reversed the reverse, changed the oil pump and now no fire.

    Quote Originally Posted by GunnerJ View Post
    I took a 350sbc cris craft reverse engine, changed it into a standard rotation and it ran great. I didnt like the low oil pressure so i installed a new oil pump. When cranking, the gauge now shows good pressure but now it will not start... backfires every now and then but no start whatsoever.

    The ONLY thing I changed was the oil pump, so I suspect the problem must be there.
    1.... Is the oil pump geared differently on the reverse rotation engines?

    I have checked and rechecked the firing order and timing, and found it to be correct.

    2..... What would be different between the original oil pump that was installed on the reverse rotation, and a new oil pump that is for standard rotation?

    3.... Logic tells me that since it was running fine in the new standard rotation mode with the original pump, the pump is not the issue, but I keep going back to the fact that the only thing I changed was the pump and now it will not start.

    Any ideas?
    1.... NO... the actual "driven" gear (which drives the oil pump) is at the end of the distributor. Not part of the oil pump.
    Cam/Distributor must turn 1:1 with each other..... the oil pump follows suit!

    2..... The pump doesn't care whether it's installed in a Std LH Engine or in a Rev RH Engine.... the distributor turns the oil pump in the same direction with either due to the difference in gear cut.
    Or.... the camshaft is 2-gear driven (not chain driven) on some.

    3.... Normally, I would completely agree with that logic when only one item has been changed.
    However, new fresh logic would suggest that something else changed that you are not aware of.

    I'd re-trace my steps and see what may now be different.
    Got to be something simple.

    .
    Last edited by RicardoMarine; 02-22-2012 at 11:02 AM.
    Rick ... aka Ricardo..... AQ series Volvo Penta repair
    Portland, Oregon
    28' SDN F/B w/ twin Volvo Penta 5.7L DP drives

    "Intellectual growth should commence at birth and cease only at death." Albert Einstein

    Please... no PMs! Post your questions on the forum.

  3. #3
    Join Date
    Sep 2010
    Location
    Jersey Shore
    Posts
    5,944

    Default Re: Reversed the reverse, changed the oil pump and now no fire.

    Are you still running points?
    Chris
    Dockside Marine Services
    Jersey Shore.
    Mercruiser/Mercury Certified
    Let the insanity begin.

  4. #4

    Default Re: Reversed the reverse, changed the oil pump and now no fire.

    No, it is electronic ignition. I have good spark.

  5. #5
    Join Date
    Mar 2009
    Location
    Portland, Oregon,
    Posts
    12,001

    Default Re: Reversed the reverse, changed the oil pump and now no fire.

    Gunner, just an idea.... but if you ended up pulling the plug wires, and when you re-installed the plug wires into the distributor cap, note that the firing order still maintains a Clockwise direction from #1.
    The only thing that changes is the sequence ......... in which all plug wires follow #1.

    Conventional Std LH engine would be as follows:


    A Rev RH engine firing order (right side image below) still begins with #1, and in the same CW rotation, but #2, 7, 5, 6, 3, 4 and 8 follow in that order.
    Note where they have positioned #1 in the cap!
    You can place #1 anywhere you want to during initial distributor indexing........, but most of us will aim the rotor to the physical location of #1 cylinder... unlike what is shown here.



    Perhaps this is your issue!

    .
    Last edited by RicardoMarine; 02-22-2012 at 03:20 PM.
    Rick ... aka Ricardo..... AQ series Volvo Penta repair
    Portland, Oregon
    28' SDN F/B w/ twin Volvo Penta 5.7L DP drives

    "Intellectual growth should commence at birth and cease only at death." Albert Einstein

    Please... no PMs! Post your questions on the forum.

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