Sundownee
An 88" plane with only a 30cc engine?? The CMPro 83" Zero is just right with the Saito 325 5cyl radial. Thats 53cc. Also great with the OS 55 gasser.
http://www.youtube.com/watch?v=ulL3j3vZzNA&NR=1 I think there is also a video on YT with the ASP 5cyl 65cc.
The World Models 80" Zero is rated for 160 2stroke although the Saito and ASP 5cyl engines are on YouTube Videos. The video below shows the Zero with a Saito 170 3cyl.
http://www.youtube.com/watch?v=B5cMH...eature=related Not bad performance and great sound!
For my money the new Saito 200 3cyl would be the choice. It's on special at Advantage Hobby for $795. Known Japanese quality, spare parts availability, and IMO a better sound than a small 7cyl radial.
BUT i know what it's like when you want a 7cyl, then that's what you MUST have !!! (what do you mean when you say the cowl is "oval"?)
Regards, radial1951
ORIGINAL: Sundownee
I am building a KMP AT-6 88 inch wing span, the new that just come out form KMP, I want to put a 7 cylinder radial in her, I like the Seidel ST7-35 it will spin a 18X8 at 5200 rpm, little over 2 hp.
the cowl (230mm width and 245 length- oval of course) is just perfect for this engine( engine is 187 mm), if it was alittle bigger like 1/2 an inch it would fit the ST7-70(engine is 235mm)
the 35 cc wieghts about 2.6 lbs and the 70 weights 5.9 lbs.
But am I going to have enough power with the ST7-35 to fly the AT-6 or will it just be alittle under power or ??
I could make a new cowl to fit the ST7-70 but it be will much heavier to setup and with 4 hp maybe too much power as it uses a 22X10 prop
thanks for you info
Paul