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Compression, good and bad

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  • Compression, good and bad

    In the next few months I would like to build the R1 engine for my '63 Avanti. I have the standard flat top pistons and a set of dished pistons (lower compression). What are the advantages/disadvantages of building it one way or the other? Has anyone here driven two similar cars, one with high compression and one with lower compression that can give me a drive report? The cost to build it will be the same either way.
    George Cagle
    North Alabama Chapter

    1937 Dictator
    1947 M5
    1948 Commander
    1963 Avanti

  • #2
    When I did mine I split the middle and went with the shallow dish pistons. I used the shim head gasket. It runs real strong and no pinging. I haven't run a real R1 to know if there is much difference.
    1962 Champ

    51 Commander 4 door


    • #3
      As gasoline becomes more and more 'watered down' so to speak, the dished pistons would probably be the smart play. (Think it will ever get to the point at SDC shows where the judges demand that a sparkplug
      be removed on the 'R' engine models to make sure the piston tops are flat???)


      • #4
        Good advice, but be sure that you know the difference between Std. 289 Deep Dished, and Special Shallow Dish, Jet Thrust/Avanti aftermarket Pistons for more power than Std. running today's Fuel.

        Not all Studebaker Vendors carry these, and neither does anyone else.

        PM me if you need a Set.
        Click on "Private Messages" at the top of the page on the Dark Blue Bar and go to "Send New Message".
        Last edited by StudeRich; 12-23-2012, 05:42 PM.
        Second Generation Stude Driver,
        Proud '54 Starliner Owner


        • #5
          To: StudeRich,-----Those 'shallow dish' spl. avanti pistons sound very interesting. Can You tell us more about them?


          • #6
            They produce 9.0 to 9.5 about the same as Truck/R2 heads, but you can continue running the thicker upper deck 1557570 '63-'64 Lark/Hawk/R1 Heads which have less tendancy to crack than the large cc Combustion Chamber Truck Heads.

            This is more important on R2's with Superchargers, you can change to the more common Lark/Hawk Heads and still have factory compression.
            Last edited by StudeRich; 12-23-2012, 06:00 PM.
            Second Generation Stude Driver,
            Proud '54 Starliner Owner