New Motor

Discussion in ''Da Nailhead' started by Bigpig455, Jan 22, 2017.

  1. doc

    doc Well-Known Member

    VELLY INTELESTING..........
     
  2. Bigpig455

    Bigpig455 Fastest of the slow....

    Got the motor home from the machine shop yesterday, and I'm totally digging the mini engine stands made by Todd Miller sold here on the board. Their made for a 455, but I redrilled them to fit the nailhead. My motor has the 65-66 GS motor mount adapter plates needed to get engine center of balance right, but those could be easily fabbed for a non GS motor...this set up is going to work great to store my retired numbers-matching motor.
     

    Attached Files:

  3. Greg Gress

    Greg Gress New Member

    Did this motor ever make it into a car?
     
  4. sean Buick 76

    sean Buick 76 Buick Nut

  5. Greg Gress

    Greg Gress New Member

    I'm puzzled, it looks like it was run on the engine stand at Tom's in 2017, and in 2019 it wasn't assembled yet.
     
  6. Bigpig455

    Bigpig455 Fastest of the slow....

    I'm flattered that you are paying that close attention. So fact is, you're right and I never really talked about it. This block was built and run in 2017, and installed in the car. Tom and I had done a 1/2 fill of the water jackets, and for whatever reason I could never get the rear of the block to cool, and the car ran hot, like "too hot" hot. We tore it back down, checked the water jackets and everything was fine, put it back together: no change. A half fill is fine on every other block but mine, but ultimately the best option was to scrap the block and move the internals over to another block. So thats the block your seeing in that link, another 66 MT . Same internals, heads, everything but different block. Happy to report that took care of the issue, and it's probably got 300+ runs on it with a best of 13.85 @99..If you have any other question, PM me!
     
    Tom Miller and sean Buick 76 like this.
  7. sean Buick 76

    sean Buick 76 Buick Nut

    you sure saved a lot of time and $ by biting the bullet and going with a different block. Very cool project
     
  8. Bigpig455

    Bigpig455 Fastest of the slow....

    Not an easy decision, especially cause it ran very well..
     
  9. Greg Gress

    Greg Gress New Member

    Old thread, so thanks for the response Rhett.
     
  10. Wildcat GS

    Wildcat GS Wildcat GS

    Hi Rhett,
    Any speculation as to what the problem was with the block?? Did you also fill the water jackets on the replacement block? Any other changes while switching internals between blocks? Inquiring minds want to know!
    Thanks,
    Tom Mooney
     
  11. Bigpig455

    Bigpig455 Fastest of the slow....

    OK, so lots of speculation on this one,. but the heat manifested itself not only on the gauge, but on the 7&8 pistons. I had a set collapse, and then had a 2nd set begin to scuff , but we pulled them while they were still serviceable. My theory is the coolant flow at the back of the block messed with the thermal expansion of the 7&8 and how it interacted with the fill, and subsequently started a process which ended with collapsed piston. Visually, and on paper everything should have been fine - we were running .0035 then .004 clearance with Tom's excellent 4032 pistons, it was a low half fill that had fully open water jackets around the side of the cyl walls that should have allowed more than enough flow, and the block had negligible core shift. No matter what we did, we still wound up with the same heat. Now I know that block filling had been around forever, and there are many Nailheads running around just fine with half fills on the street but it became apparent on this engine anyway that we had to start by restoring the total capacity of the water jackets by removing the fill. So I had the block baked to burn the epoxy out, and while it worked ok it became apparent that getting the remaining charred epoxy off the water jackets was going to be more effort than the cost of what machining we had into that block. I had a spare MT block on the garage floor, so I sent it out and had it checked, decked and bored. Came back fine so we put the all the old internals into that block and buttoned it up with the water jackets wide open ( I did order new pistons with a different pin height to match the deck of the new block ) . There was some question as to whether the radiator had restricted flow or whether I'd need a fan shroud, but the "version II" ran plenty cool just as the car was set up.

    So what's the final answer? I really don't know, but that's hot rodding: what should never work sometimes does, and what's been done successfully by hundred of guys before you just blows up for no reason.
     
    Greg Gress likes this.
  12. gsgtx

    gsgtx Silver Level contributor

    I tried to discourage everyone and you not to do it. i had posts about my 425 running hot and had to scrap the block like you did, but i ran an oil cooler and piston clearance was about a thousand more with the same race tech pistons you used which saved my pistons, just a little scuffing on the back pistons. plus after a few months the filler started coming apart and getting in the radiator. oil has to run hotter, the cylinders will have uneven expansion because we didn't fill the whole block just to bottom of soft plugs. think about it where are we going with a nail head on the street not going make over 500 hp or rev over 6000 rpms. and even doing the filler what are going gain a tenth of a second at the most. the old saying live and learn lol
     
  13. Bigpig455

    Bigpig455 Fastest of the slow....

    Next time, I'll probably listen to you. Probably...I think the issue was the uneven expansion, like you describe. "Live and Learn".
     
  14. Wildcat GS

    Wildcat GS Wildcat GS

    Rhett and gsgtx, thank you for sharing your knowledge.
    Tom Mooney
     
    Greg Gress likes this.
  15. Bigpig455

    Bigpig455 Fastest of the slow....

    Or in my case, lack thereof!!
     
  16. Jim Weise

    Jim Weise EFI/DIS 482

    Not True Rhett,

    In 30 plus years of building Buick engines, I have learned more by failure, than by success.

    If you save one guy from filling a Nailhead block, and having issues like you had, then sharing your experience is invaluable to that individual, and the community as a whole.

    JW
     
  17. Bigpig455

    Bigpig455 Fastest of the slow....

    Thanks Jim - It's not that the fill was totally wrong, it was just wrong for my application. If I was building a max effort drag car, and shutting it down at 30-40 seconds of run time it would have been fine.
     
    Tom Miller likes this.

Share This Page