How Long can rebuilt engines sit?

Discussion in 'The Bench' started by 70skylarkcusto, Jan 5, 2019.

  1. 70skylarkcusto

    70skylarkcusto God, Country, Cars

    I’ve got a buddy who just picked up a 66 gto that he got from a guy who had the engine rebuilt about 4-5 years ago but never started it. It was stored inside the car in a garage (not climate controlled) for the duration of the time.

    I was going to try to see if we could get it going today, turned the engine over by hand, turns okay, maybe a little harder than I feel it should be. And changed the oil. When I went to prime the pump it was very hard to turn and built pressure rapidly. Slow turns quickly rose the pressure to 20 psi. When I rebuilt my Buick I would prime that baby at 200-300 rpms with a drill and it would build around 30 psi. My concern is that maybe some of the assembly lube has hardened inside the oil ports and that’s why the pressure is so high with so little turning. Also when I stopped spinning the pump the pressure dropped slowly, over the course of 10-15 seconds to get back to zero.
    Should I tell him he’s got to pull the engine at this point or does anyone have any suggestions? Thanks
  2. hugger

    hugger Well-Known Member

    I'd crank it and go, I had a 455 that was built for 8 yrs b4 it was started. Sit without an intake or plugs in my non climate controlled shop, didn't seem to care
  3. scubasteve455

    scubasteve455 Well-Known Member

    16 years. Fresh rebuild. sat. i did pour Brad Penn break in motor oil in the spark plug holes. and turned with socket ratchet. i was nervous. but no worry’s .
    70skylarkcusto likes this.
  4. 70skylarkcusto

    70skylarkcusto God, Country, Cars

    Did you prime the pump before starting? My only concern is how hard the oil pump was to turn. It had tons of resistance. I’d be worried if there are some blocked passages he could damage a bearing
  5. hugger

    hugger Well-Known Member

    Oh yea, prime it for sure , being built just a few years ago it was done with a moly lube so I wouldn't sweat it, I'm not too educated on pontiac engines so I cant speculate on The pump configuration and its characteristics. In do know its similar to a Chevy style. I'm betting its fine tho
    70skylarkcusto likes this.
  6. 70skylarkcusto

    70skylarkcusto God, Country, Cars

    Thanks for the input guys. I guess we’ll see what happens!
  7. John Codman

    John Codman Platinum Level Contributor

    I'd be concerned about the really hard-to-turn pump too. I'd probably drain the oil (again) and put in something like 5-W-20 just for the initial start. I'm assuming that you installed 10-W-30. Don't throw away the oil that you just put in; if it starts and runs OK with good oil pressure, I would then reinstall what you just drained. You don't want to snap the oil pump shaft. Being from CT you can use the 5-W-20 in a snowblower or if you have something powered with a current-generation Mopar Hemi.
  8. 70skylarkcusto

    70skylarkcusto God, Country, Cars

    Yeah that’s what I was thinking because it really is hard to turn, I have this vision of snapping that shaft right off soon after I fire the motor causing break in to come to a hault. I originally put spectre 10w40 zddp oil in when I was trying to prime it. I can always go a little lower. I did have a friend tell me tho that the Pontiac’s did build high pressure compared to Buick and Chevy engines. I’d just really like to circulate more oil through the engine.
  9. 1972Mach1

    1972Mach1 Just some M.M.O.G. guy.....

    I totally understand your apprehension, but...... Prime the oil system and pop it off. I'm sure it's fine.

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