Blown head gasket

Discussion in 'Race 400/430/455' started by Briz, Sep 15, 2018.

  1. Briz

    Briz Platinum Level Contributor

    Found this when I pulled the heads this afternoon. Had no idea it was blown or how long it had been like that. KIMG0182.JPG
  2. Bens99gtp

    Bens99gtp Well-Known Member

    Nice, when it rains it pours, what compression are you running........maybe time for better head gasket than just 's felpro blue???
  3. hugger

    hugger Well-Known Member

    13to1 needs to be at the very least an Orange Crush gasket, or a Cometic, no real need for O ring copper anymore. You have head studs I assume

    I know I may have said something about it before, and I mean it with all due respect, but the combo has an issue. The parts you have should put your regal deep in the 9's. 125mph or whatever it trapped in your light chassis is 550hp or so. I just want to see it perform as it should with what it has. Look it over closely something is keeping it from making the steam it should. We are here to help each other go faster that's all. I know it's intended to be a bracket engine, but it's not on the stop or anything so it's giving all its got each pass with the exception of shift points, but iirc showed no charge from 5800 to 6200 last time out. have you calculated converter slip yet?
    Last edited: Sep 15, 2018
  4. Stevem

    Stevem Well-Known Member

    You will need to mill that head some and I would pull the other one just to see what that gasket looks like if you have not all ready.

    Did you re-torque those gaskets after the first full heat up and cool down session?
  5. Briz

    Briz Platinum Level Contributor

    I agree. yes to the head studs. The engine is completely torn down and the R side looked as if it was about to go through also. Heads and block were true. Have not done any converter slip calcs yet. When we did the chassis dyno the operator said it needed more carb. Will be sending the heads up to Finishline soon.CNC port job will help. theres lots of meat left in the heads. Hoping to maybe find someone at BG from that area to transport them up there to save shipping.

    Have pulled the R head also and the center section looks crispy like it was about to go also. We did not re Tq the heads after the dyno pulls. Builder did not think it was
    necessary. This time Im the builder. May the gods help that engine!
  6. hugger

    hugger Well-Known Member

    Yea center cylinders pushing is telltale sign of lifting imo, ALWAYS retorque no matter the engine. Especially on high compression. The Orange crush gaskets call for 3 retorques. A good 1050 carb is all it "needs" sure a 11 or 1250 would pick up just a handful of hp but only up top and probably not worth the $1k for a new one, did you experience high crank case psi? I would question cylinder sealing and converter. Box stock stage 3"s will support 650/700 so the heads aren't "the culprit" sure some CNC porting will help but that's not "the reason why" and as Steve mentioned the heads will need to be trued up, it's not flat now if it was. Regarding the head retorque that sounds like BBC builder mentality, they have 6 more head bolts than Buicks do. Even you have the extra 4 small ones along the bottom they aren't doing much with them being so small, certainly the more the better but,...
    Last edited: Sep 16, 2018
    Briz likes this.
  7. Bens99gtp

    Bens99gtp Well-Known Member

    I should be seeing Bob from finishline in the next end of month or early oct. I live in Mansfield ohio. If you can find someone to get them to me or close I would be more than happy to hand them to Bob for you. But if you have to ship to me, that's not saving you anything
  8. Bens99gtp

    Bens99gtp Well-Known Member

    Bob didn't use an orange crush or comet in mine, not sure what it is but says it's good for at least 13:1. We are about 12.2.
    I retorque mine since it's been sitting since feb, found I gained on some and motorvwadnt ever fired. Need to redo now that's it's had a few heat cycles.

    It's all about keeping the bolts/studs in proper stretch.
  9. Bens99gtp

    Bens99gtp Well-Known Member

    Check the pattern left by gaskets, if the fire ring is really close to cylinder get a gasket with a slightly larger bore size to pull that away a little bit.......if it's to close to the edge there won't be a good all around squeeze on it
  10. greatscat

    greatscat Well-Known Member

    I can bring them up Ben, not that far from you. By the way, I only run Cometic, also on the engines I build for anyone over 11.50.
  11. Bens99gtp

    Bens99gtp Well-Known Member

    The nats are not till the end of oct, I will be seeing Bob in the next few weeks. Unless you will be done in that area sooner. I will see Bob sometime after that once I get his boat fixed but not sure when that will be.
  12. Briz

    Briz Platinum Level Contributor

    Its got the header evac system on it and I dont have any leaks so I would not suspect high pressure and as far as the converter goes Im sort of in the dark on that. Its a JW (Not Jim Wise) 9" 4500 stall. Was built with the specs from the engine dyno pull and car info. I thinks it works pretty good although I really noticed her pulling hard up at the top end of the track. Right where I would normally trap for the 1/8 it feels like she gets a second wind.
  13. Tom Righter

    Tom Righter Well-Known Member

    If you need a new block let me know, i’ll make you an offer you can’t refuse.Tom

    Attached Files:

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  14. Briz

    Briz Platinum Level Contributor

    What do the caps look like? Machined for the girdle?
  15. Tom Righter

    Tom Righter Well-Known Member

    Their machined for a halo girdle
  16. Tom Righter

    Tom Righter Well-Known Member

    Every thing has been machined on this block including the cam Tunnel. Also this is a NOS block so the lifterbores are good and tight
  17. Briz

    Briz Platinum Level Contributor

    PM me Tom

    BUICKRAT Torque Rules!

    Me thinks block need a deck job.
  19. shiftbyear

    shiftbyear Well-Known Member

    Something to consider is the "factories" never retorque their head gaskets. Torquing procedures, gasket material, hardware, tools, machine work all come into play on gasket survival. Although re-torquing can't hurt, something else may have caused the failure, not ruling out defective gasket either. Good luck.
  20. sailbrd

    sailbrd Well-Known Member

    I blew an "orange crush" gasket. Switched to Cometic and never looked back.

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