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Speed,Combat,Scale,Racing => Combat => Topic started by: Matt Brown on June 11, 2020, 06:25:47 PM

Title: Engines for speed limit?
Post by: Matt Brown on June 11, 2020, 06:25:47 PM
I have a couple Russian f2d planes and considering entering SL at the Nats. I haven’t flown combat since the year of the flyaway in Lincoln NE that lit up the airport power lines.
I figured two planes should get me as far as I’m likely to get but I need at least one engine. I thought OS .25 LA or FP but not sure if they run well enough pulling a streamer. I have one FP I can use but need to turn up a venturi for it as it is an RC version.
I better get some lines tied too. What length and diameter for a .25 size in speed limit? I think I have plenty of bladder material and other supplies.

Matt
Title: Re: Engines for speed limit?
Post by: pmackenzie on June 11, 2020, 06:29:48 PM
.018 x 60' lines
LA and FP .25 are fine for SL, 8x5 master airscrew scimitar is a good prop for either one.
Add tail weight and tip weight, and don't be shy about the latter :)
Title: Re: Engines for speed limit?
Post by: Bob Mears on June 16, 2020, 08:38:19 AM
K and B 28 is working great for me.  http://www.mecoa.com/kb/aero/controlline.htm
Title: Re: Engines for speed limit?
Post by: phil c on June 25, 2020, 02:27:29 PM
If you want to risk an expensive engine several people fly with F2D motors(old ones) on6-6.5in. props, trimmed down, smaller venturi(don't know the size).  This setup turns a bit tighter but has more trouble in the wind.  The longer lines do make the plane more touchy so longer mounts or weight, or other trimming is needed.

The K&B 28 is a nicely built engine form MECOA.  They'll build it up with a venturi and needle valve for C/L.  Performance wise it is pretty much even with the OS engines, but an ounce heavier, so the plane either needs to be a bit bigger or some other adjustment.