This month's ( July 2002 ) SCC has a really neat article explaining rod/stroke ratio and what it means to you and me. I found it interesting because I'd been thinking about a B20 crank for my B18B1. Pick it up if you're curious...

 

the LS and B20 cranks are identical.

I'm curious about that Nissan 1.6 motor with 2.1:1 rs ratio ... making 200hp out of a 1.6 liter is insane.

Greg

 

Maybe he means a B20A('2.0 lude engine).........If that's the case then your r/s stroke ratio would go in the *******.

 

But with that a high a ratio, isn't the power band typically narrower, or rather, pushed up more in the rev range. The piston moves pretty slow at that a high a ratio, right?

[Greg: Still talking to people at work for you, haven't come up with anything yet]

 

hey, its close, the higher RPM you go, the more work the motor is doing in less time i.e. what makes it pull the car faster, thats where high rs ratio comes into play ... there is hardly any low end, everything is on top.

Thanks, lemme know how you make out.

Greg

 

yeah basiclly longer lod=less stress \
shorter rod better reponses. hoat iam drunk maybe

 

Added bonus: chicks like a longer rod

 

nah...chicks like a bigger BORE.

Maybe we should change the subject to Bore/Stroke Ratio.

 

Yeah, that's what I'd heard (did a search! ). I liked the article because it explained to me why it's a lousy idea in greater detail. Guess I'll stick with my 1834 CCs for now.

Maybe I could get the rods from that Nissan motor...

 

Which is odd, because most guys prefer a smaller bore.

 

Can anyone explain how the rod stroke ration affects the output?

 

Dwell time at TDC, basically. A longer stroke spends more time at TDC, and so gets a more efficient burn at low engine speed. Vice-versa for a short stroker.

The SCC article explains it much better...

 

I thought it was a pretty decent article.

ilr, who is wondering about raising the block deck height and throwing in a longer rod.