[DMCForum] Re: Explaining Horsepower For Jim Strickland AGAIN

["content22207" <brobertson@xxxxxxxxxxxx>]

Torque, torque, torque.

Horsepower doesn't even exist without torque (it is one half of the
equation).

A low rev'ing high torque engine will out pull a high rev'ing low
torque engine every time. Absolutley 100% guarantee it.

Some buzzy little engines produce 100 lbs *OR LESS* of torque. Their
HP numbers are totally dependent on rev'ing the ever living mess out
of them. BUT ONCE YOU LOAD THEM DOWN (a trailer, a hill, etc) THEY
CAN'T REV UP! Are then as useless as nipples on a man.

With all due respects, I'm not holding my breath for you and Martin to
engineer a workable transmission to replace Mack tractors with Honda
Civics...

Bill Robertson
#5939

>--- In DMCForum@xxxxxxxxxxxxxxx, Jim Strickland <ihaveanaccount@xxxx>
wrote:
> Time for some new words, bill.
> 
> You say that 300 horsepower engine can be more powerful than a different
> 300 horsepower engine.  Obviously you are not measuring how 'powerful'
> something is with horsepower.  What are you measuring?
> 
> The car could tow the trailer if geared correctly; the same reason that
> the mack truck with 400hp will never be faster than a 60hp civic.  
> 
> 
> 
> On Mon, 12 Jan 2004 21:22:31 -0000 "content22207"
> <brobertson@xxxx> writes:
> > Andrei, Andrei, Andrei -- don't fall into the HP trap. 
> > 
> > Horsepower is calculated from 2 numbers: Torque and RPM's. An engine
> > that "only" produces a couple hundred HP, but does so at low RPM's, 
> > is
> > MUCH more powerful than an engine rated even higher at high RPM's.
> > 
> > Consider a semi trailer tractor. "Only" puts out 300-400 HP. But it
> > does so at 1,500 RPM. Do you suppose your Porsche -- with the same 
> > HP
> > rating -- could pull 80,000 lbs as that tractor does? The answer is 
> > of
> > course "no" because it would never be able to rev anywhere near its
> > power band (actually it would stall the minute you let the clutch 
> > out).
> > 
> > Domestic big blocks have tremendous torque -- 3 or 4 times as much 
> > as
> > a little sports car engine. That's why you see people towing boats 
> > and
> > trailers with a Cadillac, but never a Honda.
> > 
> > FYI: HP = Torque x RPM / 5252.
> > 
> > The 450 HP rating of your 454 is probably a gross number, calculated
> > out of the vehicle with no accessories on the front. That's the way
> > American manufacturers did it in the 1960s. Actual net HP in the car
> > averaged a hundred ponies or so lower. Domestic manufacturers 
> > switched
> > to net HP ratings at the same time they dropped compression ratios 
> > --
> > lower compression does lower HP, but not as badly as the 1972 
> > numbers
> > make it appear.
> > 
> > If you're having problems with the 454 in your boat, consider a Ford
> > 460. I know it's a popular marine application.
> > 
> > Bill Robertson
> > #5939
> > 
> 
> 
> ________________________________________________________________
> The best thing to hit the internet in years - Juno SpeedBand!
> Surf the web up to FIVE TIMES FASTER!
> Only $14.95/ month - visit www.juno.com to sign up today!

Yahoo! Groups Sponsor

ADVERTISEMENT

---

Yahoo! Groups Links

• To visit your group on the web, go to:
  http://groups.yahoo.com/group/DMCForum/
   
• To unsubscribe from this group, send an email to:
  DMCForum-unsubscribe@xxxxxxxxxxxxxxx
   
• Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.