Real HP loss numbers

[Clive Apps Techno-Logicals 416 510 0020]

> 
> I have wondered about this myself.  I have heard anywhere from 15%
> to 25% in drivetrain losses.  What I can't figure out is where the
> energy is going.  If you have a 300HP engine with 25% drivetrain
> loss, then you are losing 75HP somewhere.  Since it doesn't just
> disappear, something has to be soaking up 75HP of energy.  My
> guess is that the loss would be in the form of heat which would
> mean of lot of drivetrain parts would have to be getting really hot
> (assuming the 300HP load on the engine).  Since I have only seen
> my transmission get warm, it doesn't really make much sense unless
> I just haven't had the load on for a long enough period.


just estimate how much torque it takes to compress a valve spring
multiply x 1/2 revs x # springs X length of valve travel x
x losses in the vlave gear and add in the amount that it takes to
move the valve train components around
15% sounds reasonable
on 300 HP that would meav that another 52 HP was being eaten by the engine
to move the valves

Clive 

>
 
> I wonder sometimes if people don't estimate drivetrain losses on the
> high side because they don't want to admit that their engines aren't
> as powerful as they want them to be.
> 
> Dan L
> 
>