i have a LS block and Crank..

i want to know what crank will give me the best R/S ratio

B16, GSR or LS

Also what CC i would get with a B16/gsr/LS at 85MM

Thanks

 

b16 crank would yield the best ratio. Go to c-speed.com to calculate compression/displacement

 

what will the r/s ratio be??

 

With a B16 the r/s ratio would be 1.85, but if you used a B17 crank it would be 1.75.....perfect.

 

I know there have been posts on here before, but how important is R/S ratio really. Anybody have any real experience, bad or otherwise, with really wacky stroker-induced ratios. I have read a few commentaries about how far too much attention is given to this. Any thoughts?

 

Its very important if you plan to rev the engine high.

Take a look at this graph of piston velocity vs crank angle at 9000rpm with different r/s ratios.



The differences of the crank angle at TDC and BDC are pretty apparent.

 

I understand that there are going to be differences with the angles of the rods, etc. But what does that really mean for performance and reliability? Can't you have a terrible ratio with strong parts and still have performer? I see and understand the numbers but has anyone actually had engine problems or failure that they can directly attribute to a bad R/S ratio?

 

R/S ratio actually has a very small effect on maximum piston acceleration. Stroke is mainly responsible for the differences on that graph. It's more side loading that's the main issue.