Back in the muschle car days, they would do everything they could to
come up with a max Hp rating to advertise. IIRC, one major mfr took
all the accessories off the engine (water pumps, generator, etc. and
even used a vacuum system to extract waste gases to get a MAX number to
put in the ads.
I remember hearing that a mfr of industrial equipment ordered 60 hp
engines from both Caterpillar and from Ford to test for some continuous
duty application. The ford engine failed miserably when asked to
deliver 60 hp continuosly, even though it was rated for it. I have a
Ford engine in my backhoe. It has 3 different HP ratings, all the way
from 62 HP down to 42 HP depending on whether its pumping its own water,
etc., I consider it a 42 HP engine and it behaves that way.


Pete Stanaitis
-------------------------

Christopher Tidy wrote:

Hi all,

This group often sees questions about ratings (can my 2 hp electric
motor develop 3 hp? can I draw 150 A from my 100 A supply? etc.) so I'd
like to ask a rating question. I think this one might spark some debate.
If you buy a good electric motor, the power rating is a continuous one
(or it says otherwise). Same with most pieces of industrial equipment.
But what about a car? Is the 130 hp or whatever maximum engine power the
manufacturer quotes a continuous or an intermittent rating? I was always
under the impression that it was an intermittent rating, though quite
where I got that idea I can't remember. I'm not asking if the engine
will wear out quickly developing its maximum power rating continuously -
I'm sure it will - I'm just wondering if it will overheat?

Any thoughts? Just a matter of curiousity...

Best wishes,

Chris