Alr11606

Ok any machinists on here, Looking to move to a 101mm stroke when I rebuild my engine soon, (we're limited to roughly 7k, might as well make that close to max!)

So by my math, (correct me if I'm wrong) a 101mm stroke is 3.976" and would require at least .250 welded onto the journal and more along the upper portion to be able to machine the filet. Would this be reasonable? I know it can be balanced using heavy filler in the counterweights but I'm curious of strength. Old stroker V8s were done this way but didn't have near the pressure per cylinder this will have.

Looking at pictures of the block and girdle everything will fit with some massaging, and the sleeve can dropped below factory bottom to keep the skirt happy.


A 101mm stroker with a 5.900 rod and 1.125 comp height piston is possible staying within the "hybrid stroker method"

Also looking for a 944s2 crank with bad rod journal(s) and S2 block with hurt cylinder

Thanks for any input,
-Austin

V2Rocket

Hi,
I am almost certain there isn't enough physical space in the block/girdle for a 101mm stroke with a typical H-beam - unless you've got some really small rods/rod journals in mind?

I was looking into having a batch of billet 95mm-stroke cranks made with 2.0" journals (Chevy size) and the H-beams for that size would've been almost touching

Regarding balancing, since it's an inline 4 cylinder you don't need to add anything - an I-4 crank only balances against itself - the rods/pistons have nothing to do with the crank's counterweights.

Alr11606

Well, I'm not afraid to clearance the girdle a bit, more worried for true block clearance and how far the sleeve would have to be notched,

I wish I had a spare S2 block and crank in front of me to check everything out.