http://www.hotrod.com/howto/69883/

There seems to be a lot of confusion on this website abut the ins and outs of stroking. This article should help some - it is all about a Checy SB, but the relevant issues are the same.

RE: Compression ratio - stroking an engine requires keeping the CR within acceptable limits. For the S2000, they will need to modify the port or the piston crowns to keep things cool.

Formula: cylinder volume + combustion chamber volume / combustion chamber volume

This will yield a number that will help determine that critical factor. If it came out to 9.4 one could run 89 octane. f it came out to 12, super premium (beyond California 91) would be needed and would likely be unacceptable

The other main issue is piston speed - excessive piston speed will affect longevity, as will any tendency of the longer conn/rod - piston to wobble at the top of the stroke, since the axis at the crank pin will be longer and more subject to movement at the top of the compression stroke as the conn rod to piston pin revolution reverses.

Piston speed is calculated as follows:

piston speed = (stroke x 2 x RPM)/12

There is a "generally regarded as safe" range for piston speed, and it is well known to the mech engineers who design engines.


Given Honda's expertise, I am not losing any sleep that they will get it right, and no doubt there have been "mules" on the dyno and runing ballz-out on the street to test the new 2.2L mill.

All the fear and loathing being thrown at the new engine without day 1 of driving makes me scratch my head - as an engineering oriented person, I say let the accused have a fair trial, then hang 'em.

This is the 2004 version of the "Ox Bow Incident".

 

Thanx for the info Road Rage.

I agree, with all the criticizing going around you would think some of these people have already driven the '04s.