stroker build questions

[31Express]

Greetings all--new member here hoping for some direction on building a sbc stroker for my single engine 7500lb cruiser. This will be a carbureted low compression, (9.1-9.3) low rpm (max 5000) engine to cope with the vagaries of marina gas--and will use Enginequest's cast iron vortec heads. I'd like to use 2618 alloy forged pistons for extra resistance to detonation. Problem is, nearly all are designed to be used with 6 inch rods. I've read that marine engines will be happiest with 5.7" rods--but there are very few forged pistons designed for 5.7 rods and low compression--even fewer using the 2618 alloy. The rotating assembly I'd like to use features 6" rods and reverse dome d-cup pistons(2618 alloy) with a compression height of 1.140 and 24cc dish. Will this be appropriate? BTW--the cam will be fairly mild--designed and ground by Marine Kinetics.
All thoughts gratefully accepted!!

 

[Scott Danforth]

On a 7500# boat, I would be going big block or big block striker vs small block stroker.

You would be fine with 9.4 to 9.5:1 compression ratio as that is what the vortec sbc's came with. Also RPM. Up to 5500 . You cam profile will be based on your exhaust as much as the rest of the build.

Regarding the rod lenght, it is true that the shorter rod is slightly better, however almost not enough to worry about. Crank throw weights and balance (internal vs external) ultimately impact rod length. Shorter rod requires shorter weight throws requiring more mallory metal during the balancing operation or external balance.

Regarding the pistons, I was looking at a 12cc dish when I entertained the sbc stroker before going bbc

 

[Bondo]

Regarding the pistons, I was looking at a 12cc dish when I entertained the sbc stroker before going bbc

Ayuh,.... Welcome Aboard,.... Forgetabout the forged pistons, ya don't need 'em,....

There are hyperutetic pistons with either the 12cc or 18cc D-dish, that with 5.7 rods, 'n deckin' the block can get ya in the 9.5 to 10:1 compression ratio range,....
The Vortec heads are enough to keep detonation under control,....
Especially if ya keep the quench 'round .040 to .045",...