Gentleman, I bought a S&S Evo Super Sidewinder bottom end with the 4.25 flywheel assembly, it was paired with 4 inch bore jugs for a 107CID engine.

My question is I know the S&S built 113 engines were a 4 inch bore with a 4.5-inch stroke, but can I run 4.125 jugs on my 4.25 stroke to get to the same 113cid?

The cases are S&S 31-0024 the same cases that S&S used with 4.125 bore and a 4.625 stroke for their evo super sidewinder 124 engines, so I am thinking jugs and pistons should be available?

Any thoughts?

Thank you in advance for your time and consideration.

 

That's a huge amount of money spent for virtually no real increase in anything but 6 cubic inches of displacement.
A 4.25 stroke has less piston speed, so will last longer than a longer stroked engine. I say this owning a 4,5" stroke 113" engine and a 4.625 stroke 96" engine, both of which run just fine.

Griz

 

Can't be done with S&S of the shelf pistons, wrist pin location will be the issue on the larger bore pistons plus your flywheel should have Evo .792 pin sizes, big bores have .927's

 

I think you're best bet would be to stroke it.. 4.625 it..