wrote in message
...
On Sun, 15 Oct 2006 10:42:35 -0400, "Eisboch"
wrote:

The problem is you have it backwards. A typical Nissan V6 engine
(3.3-liter SOHC 12-valve) has a bore of 3.602 inches and a stroke of
3.268 inches. This is called "over square" and is typical of high
reving,
low torque engines.

Back in the olden days short stroke engines were very common (a 302
was a 327 with a shorter stroke). Then the emission controllers said
longer strokes burned cleaner and we ended up with 350s and 307s that
were long stroke engines. I suppose now days they have found better
ways to clean up the exhaust so they can go back to short stroke vigh
rev engines. My Vtec Honda redlines at something like 8.5k. The cam
shift doesn't happen until 5k.

Those really aren't representitive of the "olden days". The old, straight 6
and 8 engines had relatively long strokes with small bores ... mainly to
they last for a reasonable period of time without blowing up. Lots of low
end grunt, but limited in RPM. New, high reving engines typically have
larger bores and short strokes with peak torque much higher up in the RPM
curve.

General rule of thumb:

Longer stoke, smaller bore = low end torque.
Shorter stroke, larger bore = higher RPM, lower low end torque

For example ... A Ford F1 race car V8 has a bore of over 4 inches but the
stroke is just
over 2 inches. Sucker revs to 16,000 RPM.

Basskisser is kissing bass.

Eisboch