On Sat, 10 Oct 2009 11:19:38 -0400, wrote:

On Sat, 10 Oct 2009 11:01:54 -0400, "Ed Pawlowski"
wrote:


"Worn Out Retread" wrote in message
...
I am looking for a new snow blower and have discovered that the power
rating of the engines are no longer in "Horse Power" but in "Foot Pounds"
if given at all. Sometimes all that is given is the CC's of the engine.

Even the people selling these machines don't know what the "Horse Power"
ratings are so that old geezers like myself can understand what is going
on. Does anyone have any general rules regarding the conversion of Foot
Pounds or CC's to Horse Power?

Horsepower to CC is highly variable and not a good measure of power. My
cars have different engines. The 3800 cc is 190 HP but my 3300 cc is 234
HP. I suspect smaller engines are similar.


For the types of engines generally found on lawn equipment, comparison
of new engines and old engines of same brand and displacement is a
valid comparison. These are utility engines designed to run at optimum
RPM's while in use. A car engines is vastly different in it's
requirements.

If an old snowthrower with a 13 hp Briggs engine is 350cc, then a new
350cc Briggs powered snow blower will be about the same HP.
Unless the old 350cc 13hp Briggs is a "side valve" engine with 5.6:1
compression ratio, and the new 350cc engine is an overhead valve
engine with 11.5:1 compression ratio - which MIGHT be a 18HP engine.

Numbers just picked out of thin air, but the principal is there.