> Sure, I've done many, many speed measurements, especially lately with
> all the flow testing I've been doing on the wings and I'm happy to
> share my numbers. Mine is a trigear with an empty weight of 909lbs.
> The C of G is a little over 60". Typically what I see on a 75F day is
> 134 kts in cruise at 2850 rpm at 3500' burning 4.6gph according to my
> Grand Rapids fuel flow meter. One recent cross country flight I saw a
> TAS of 148kts at 7500' at the same throttle setting.....
>
> I have flown at 1450 lbs gross on several occasions and I'm still
> climbing in the neighborhood of 1200-1300 fpm. If I back off to 2650
> RPM, I cruise at 125kts and my fuel burn goes down to 3.8- 4.0 gph. I
> have worked hard on getting the mixture well balanced between the
> cylinders by playing with the needle jet and needle setting, as well
> as the float level in the carby. I''ve also twisting the carby
> slightly left from vertical to even out the mixture. I now have EGT's
> all within about 40F of each other and my plugs are a nice tan color.
> I also am running the Iridium plugs now with great success. This
> engine will idle at about 500 rpm with the Iridium plugs and still
> maintain about 22psi OP. I believe I have a handle on the cooling
> thing on all but the hottest days, and then it's only an issue in
> extended climbs on the #4 cylinder.
John,
Thank you for providing those much interesting numbers.
Very interesting data, indeed, and I'm sure many homebuilder will be
interested in how you achieved a successful engine installation.
Best regards,
--
Gilles
http://contrails.free.fr
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