LoPresti cowling

[jamesmil]

hi guys, has anyone ever changed the front of the cowling and used round openings sush as the lopresti cowling?
just an idea, i think it would look good but wondering about cooling.
would like to hear what others think. pro and con. thanks

[Av8r3400]

What motor would you want to wrap in this cowl? That would make a difference.

A 912 does not need a bunch of cooling air and some planes with this motor have very small (looking) openings. In a Kitfox application, a fancy highly aerodynamic cowl design is fairly wasteful due to the relative low speed of the airplane.

My 80 hp 912 will already get to airspeed redline (125mph) in straight and level flight in my model IV with a round (very draggy) cowl, with the prop pitched for speed. I'm now pitched for climb/STOL operations and can still see 120 mph on a nice smooth day.

A smooth cowl SS with 100 hp would probably push it's 140 mph redline with the right prop settings, too...

IMO, in the world of 912 powered Kitfoxes, a LoPresti style cowl would add nothing other than cost and sex appeal.

[jamesmil]

thanks for the reply av8r3400, more info would help. yes we are using a 912. the lopresti style cowling would look cool but the reason we are thinking of doing it is we have a lot of work to do around the nostril area of the cowl. it will be easier to do the round openings like the lopresti.
not looking for speed as we have 850 tires and no wheel pants but want to make sure we dont create other problems such as with cooling.
open to any info anyone might have on this subject. thanks

[desertfox1]

I've been flying a Model 7 with a cowl designed by Bill Prokes for
the last year or so. It has the round inlets and cools very well.
Phoenix summers and high performance climbouts have never
given over 190 degrees oil and 210 CHT. I'll attach a snapshot.
The hole under the spinner is for a LED recognition light.

Phil

[jamesmil]

great info desertfox1, thank you. your cowl looks great hope you don't mind us being a copy cat. that is what we had in mind but were worred about the temps. thanks again

[BlueRidge]

believe the primary consideration for this cowling was weight reduction, it was made out of carbon fiber, suspect the "LoPresti" inlets was just styling.

Does anyone know how much weight was saved with this cowling over a stock cowling?

[desertfox1]

The boot cowl, upper and lower cowls and the NACA duct saved
8 pounds. Good, but not earth shaking. We saved over 50 pounds
total on the aircraft, with many other items coming into play. Attached
a pic of 2 pound upper cowl.

Phil