bossvette
Gone but not forgotten
A nice aluminum block would keep the weight down :cool
did you order wheelie bars yet? :L
did you order wheelie bars yet? :L
Looking to go beyond 502c.i. with short deck
- Thread starter 67HEAVEN
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- Corvette
- 1959 black 270hp (9/2/69) 1981 Beige L81(10/20/80)
Mark IV Limitations
Bob,
It seems that a reader of Hot Rod had the same question, sort of, and some of Marlan Davis' reply sheds a little light on our discussion here.
Basically a short deck Mk IV will take a 4.25 stroker with clearance grinding on the pan rail. There are a couple companies that make a stroker oil pan to clear the crank as well after the rail is clearanced. Agressive grinding on the pan rail may uncover the main oil gallery (a bad thing ). Short skirt pistons are required to clear the crank throws. Also rod angles get severe above this.
With the 4.25 stroke and a 4.310 bore you get 496 cubes. About the max for a short deck Mk IV. Falls short of what you are seeking. The best way to do a 496 is with a tall deck and use 6.8" rods.
Gen V/VI and Bow Tie one piece rear main seal blocks have the main oil galley moved to above the cam so they can accommodate a longer crank without running into problems (clearance grinding).
So it looks like if you want to go above 4.25" stroke you will need to use a Gen V or VI, Bow Tie or step up to a Merlin short deck.
For the rest of the poop read the Q&A titled Chevy Rat Truck Blocks on page 95 of the March '04 issue of Hot Rod Magazine.
Tom
Bob,
It seems that a reader of Hot Rod had the same question, sort of, and some of Marlan Davis' reply sheds a little light on our discussion here.
Basically a short deck Mk IV will take a 4.25 stroker with clearance grinding on the pan rail. There are a couple companies that make a stroker oil pan to clear the crank as well after the rail is clearanced. Agressive grinding on the pan rail may uncover the main oil gallery (a bad thing ). Short skirt pistons are required to clear the crank throws. Also rod angles get severe above this.
With the 4.25 stroke and a 4.310 bore you get 496 cubes. About the max for a short deck Mk IV. Falls short of what you are seeking. The best way to do a 496 is with a tall deck and use 6.8" rods.
Gen V/VI and Bow Tie one piece rear main seal blocks have the main oil galley moved to above the cam so they can accommodate a longer crank without running into problems (clearance grinding).
So it looks like if you want to go above 4.25" stroke you will need to use a Gen V or VI, Bow Tie or step up to a Merlin short deck.
For the rest of the poop read the Q&A titled Chevy Rat Truck Blocks on page 95 of the March '04 issue of Hot Rod Magazine.
Tom
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