<VV> Actual vs. advertised hp

[Dave Morris]

William Wynne has built a dyno and is doing comparisons between Corvair 
engines and certified aircraft engines.  He has already determined that the 
Continental O-200 engine that is called a "100hp engine" really only puts 
out 75hp net, and that the Corvair 110 puts out more than 75.  He has not 
yet published all his data, but if you keep an eye on this page: 
http://www.flycorvair.com/thrust.html you should be able to see what he has 
been able to measure pretty accurately for Corvair engines with a prop 
attached.  I know it's not exactly what you're looking for, but might 
provide some interesting insight that you don't otherwise have.

Dave Morris

At 10:32 AM 3/10/2005 -0500, you wrote:


> >Would one of those electronic gadgets like Ned was using be accurate enough?
>
>
>No, because the gadget calculates HP using acceleration and the formulas 
>used at best could only calculate average HP, not true peak HP. They do not
>accurately calculate hp on turbocharged engines nor any engine with a 
>really sharp hp peak. They are best used to compare modifications on a 
>single engine
>given a starting baseline, not to really compare engines to each other. 
>However, it would give us a good idea of "real world" performance.... does 
>a lower and
>wider torque curve mean more than a high sharp curve? And to what speeds? 
>This is the sort of thing that allows a 140 to outrun  180 to certain speeds.
>
>Even using chassis hp as a comparison is also somewhat suspect becuase of 
>the ptential for different levels of parasitic loss between cars, but 
>would indeed
>be a better way of doing it.
>
>Bill Elliott
>
>
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