Gas V8 SV Compression/Boost/Machining limitations

Discussion in 'The Skunkwerks' started by Pbrmeasap2112, Feb 10, 2019.


  1. Pbrmeasap2112

    Pbrmeasap2112 Farmall Cub

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    This is a theoretical conversation at this point. Open to all.

    What limits, experienced or percieved, does the SV engine (266,304,345,392) have for compression (nevermind fuel limitations. I'm talking strictly physical properties of this robust beast of an engine. )

    To be clear I'm seeking to take this thing to the moon. Diesel territory. 15:1-23:1

    I can't forsee many if any, given the severe circumstances for which the block was engineered. To my understanding, they all have completely forged internals (crank, rods, Pistons).

    My big questions are :

    how many different size combustion Chambers were there?

    What are milling restrictions on the heads?

    What are the decking limitations of the block?

    Are there any off the shelf pistons compatible with our engines?

    Thanks
     
  2. chris@profab

    chris@profab Farmall Cub

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    If you're looking at adding a blower, I wouldn't worry about decking etc. "It's not the size of the motor, it's the size of the blower"
     
  3. scout2000

    scout2000 Y-Block King

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    subscribed.

    Not a project that I would take on myself, or recommend to others.

    Still, I'm happy to grab a bag of popcorn and get comfy in my favorite chair, and watch where you're headed with all this.
     
  4. ruderunner

    ruderunner High Wheeler

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    One could research the MV series engines, they make much better diesels than gassers
     
  5. JordanAMC

    JordanAMC Binder Driver

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    Funny... Be got a buddy who has amassed some 392s with the intention of adding turbos and such... His dream is to market the changes to the IH community as a product. You should give him a call. Fullonauto.com.
     
  6. Gus Erickson

    Gus Erickson Farmall Cub

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    My 392 has Chrysler 413 standard bore flat tops in it.
     
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  7. Tom Mandera

    Tom Mandera Dreams of Cub Cadets

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    10 or 10.5:1 is achievable using common parts

    I offset grind the crank to add a little stroke and more compression.

    I deck the block - typically .040 or so gets you to zero deck with .040 rods with .035 offset grind and FM H996 or 997 pistons.

    You can take a little more off and let the pistons top out of the deck .015 maybe a touch more.

    With normal-ish heads you are probably at the 10-11 range.

    You can milk .100 or more off the heads for some more compression.

    Plan to angle mill the intake at that point.

    Run the 413 or Cad 425 pistons and you can dome them for more compression.

    Or offset grind the crank and resize for Chevy rods and you can basically build a 454.

    I don't recall what that does for compression though.

    Boring.. every block I have Sonic tested will take a ton of overbore.. and they have held up to a lot of abuse following such machining operations.

    (Went through two cutter bits boring the block..)

    Sent from my Moto Z (2) using Tapatalk
     
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