Simple question for the big block Chevy guys.

Discussion in 'PSI Superchargers Tech Questions' started by T-Wrecks, Nov 13, 2021.

  1. T-Wrecks

    T-Wrecks Member

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    What is the absolute minimum pin height for a piston with a 1.094 pin? Something that will run not run once. Big Duke heads if it matters. Goal is 1700+/- hp
    At this point I have a new 4.25 Velasko crank and new Fowler LW 6.620 rods. Can I successfully squeeze that into a 9.8 deck or just carry the extra weight of a 10.2 deck?
     
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  2. rb0804

    rb0804 Active Member

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    I got a set of 1.27 CH pistons with a 1.094 pin and there is like no room between the bottom side of the valve relief and the top of the rod. Don’t know if it matters or not, but that’s for a 14* head.
     
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  3. T-Wrecks

    T-Wrecks Member

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    my plan is for the 10.2. I do know some engines are built with less than a 1 inch pin height. Was just curious if anyone had actually built an engine that way.
     
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  4. bandit496

    bandit496 Member

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    FWIW, here is what has been successful for me both in supercharger and turbocharger trim. 4.25" stroke, rod length 6.650, wrist pin .990, compression height 1.450, bore size 4.505. I use this configuration on both supercharger and turbocharger applications with Dart 410 and Brodix SR-20 heads. The only thing that changes is the dome/relief configuration on the piston top. I shoot for 10.25 to 10.5 compression ratio. I would surmise that we are in excess of 2000 hp, especially with the turbo application, but never dynoed, just guesstimate based on fuel consumption. Have used this configuration for a long time with relative success.
     
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