Piston to Valve Clearance Check

Discussion in 'Small Block Tech' started by patwhac, Mar 25, 2021.

  1. patwhac

    patwhac Well-Known Member

    So I just realized the other night . . . one important thing that I forgot to do on my 350 build is check piston to valve clearance after installing my camshaft. Here's my cam card below, can anyone tell me with certainty if I will have issues?

    I roughly measured my pistons as being about 0.090" down in the bores when I had the heads off. Now everything is together almost ready to break in and I don't want to wipe the lube off the cam/lifters turning the engine over by hand, even with the rockers/pushrods out.

    Actually I didn't check the valve springs either . . . I'm leaving the stock springs on for the break-in, then switching to TA Stage 1 springs after. Should I have checked installed height and coil bind or can I wait until I change springs to do this? How would I even do that with the lifters not pumped up?

    Cam card:
  2. sean Buick 76

    sean Buick 76 Buick Nut

    With the pistons that far in the hole and that mild cam you are safe as long as the cam is degreed properly.
    patwhac likes this.
  3. Fox's Den

    Fox's Den 27 years of racing the same 355 Buick motor

    miss by a mile
    patwhac likes this.
  4. Stevem

    Stevem Well-Known Member

    .090" in the hole!!!
    That's right at very limit of big time sucking / bad!

    Don't expect the best / most that such a Cam swap has to offer with that amount of deck clearance being run, in fact I would be placing Rhoads veri lifters in that motor !

    I would also advance it right off the Bat 2 degrees to make up for the eventual sooner then later timing chain stretch condition .
  5. walts72

    walts72 Well-Known Member

    Plenty of room
    Pav8427 likes this.
  6. Mart

    Mart Gold level member

    Yep, more clearance than stock.....
    walts72 likes this.
  7. alec296

    alec296 i need another buick

    .090 in the hole. 3.0 pistons?
    Cam specs sound good. Turbo grind?
  8. sean Buick 76

    sean Buick 76 Buick Nut

    There is no quench zone on these engines, open chamber head design. His block has a taller deck height being a 75or 76. The pistons are lower compression height vs stock. But none of this really matters as it’s got good compression test tests and it’s being turbocharged.
    Dadrider and Max Damage like this.
  9. patwhac

    patwhac Well-Known Member

    Thanks all for the replies! Glad to hear I'll be ok. Yes it will be a twin turbo build, and keep in mind I measured only 1 bore with a pair of digital calipers so really not the most accurate measurement, more of a ballpark. I really should have measured everything but live and learn. Sean is correct in that I believe this to be a 75 or 76 smogger block, hence the terrible quench.

    Also cam was degreed per the cam card, intake to 114.
  10. sean Buick 76

    sean Buick 76 Buick Nut

    I just milled the deck on a 75 block 60 thou to get the pistons to zero deck, very tall deck height on these. I only bothered because I’m using closed chamber heads, if I was using the factory heads I would have left it alone.
    patwhac likes this.

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