So, I don t know.  We need some data.  Tracy is guessing that his engine puts out 180hp. Could be; but I m guessing we don t know what it is, and it could just as likely be 165.

Al

 

Al,

 meant to ask you earlier if you had any fuel flow data during the dyno pulls. 

Unfortunately the fuel flow meters were not working properly; too much scatter in the data to get meaningful results during the power pulls.  We did just three steady state runs where we did time and weight of fuel data recorded manually.  When I left with my engine that data was left at the facility.  Supposedly, the dyno operator was picking it up on Sunday, but I haven’t heard form him.  The one cruise data point that I have was at 5000 RPM running lean of peak (EGTs about 1560), MAP of 23.8, 155hp; BSFC was 0.49 lbs/hr.  Soon as I get the other data points I’ll let you know

 Assuming we know approx. BSFC, we can make a guess on HP based on fuel flow.  Sure hope I'm making more than 165 because if that's all it is, my BSFC works out to 73, which would be incredibly lousy.  At best power mixture and WOT the rotary is said to be around .65 which works out to 185 HP at 20 GPH

I’ll take fuel burn is a reasonable guesstimator.

Here's another possible indicator.  When I was running an untuned carburetor manifold, maximum fuel burn was 16 GPH at best power mixture.  With my tuned EFI manifold that number went up to 20.  Not as good as a dyno number but definitely indicates that the engine is pumping more air through it.

No doubt that’s a major improvement.  How much of that is due to the “tuned” runners, and how much due to going from; let’s see, I’ll kindly call it a “less-than-optimum” carburetor setup, to EFI.

 

Tracy

Going back to my original posting of the data, I said “> I won't argue the case for/against the longer so-called 'tuned'  induction runners,>  I guess I should have stuck to it.

Also, I’m a bit confused right now because I just looked at some dyno data from Alturdyne, and I find it shows shows about 4% more torque at 5500 RPM than mine and 24% more hp!  Something definitely not right somewhere. 

 

Al