Building Tips and technical articles. => ARF'S => Topic started by: Chris Lambdin on June 28, 2021, 10:11:43 AM

Title: Brodak P-40 arf power?
Post by: Chris Lambdin on June 28, 2021, 10:11:43 AM
Would an FP-35 be strong enough for the P40 arf? I was thinking about trying the P-40 and I have a good FP-35 setting on the bench.
Title: Re: Brodak P-40 arf power?
Post by: Walter Hicks on June 28, 2021, 01:28:36 PM
Chris, If you are Sport Flying, and not competing the FP .35 will work. The P-40 has a fairly thick wing so it requires more power to pull it. If you use the FP .35 get an old Tornado/Grish 10x4 Three blade prop and run the motor at 10,000 rpm and it will probably work. On the other hand if you plan on use the plane for Contest Competition then use a LA 46. My ARC that I covered and painted uses a Super Tigre 46 with an ABC Piston and liner. Mine weighs
between 52-54 ounces. If you can't find the three blade then use an APC 10.5x4.5 and run it around the same RPM. The Stock Muffler on the FP .35 needs the exhaust stinger opened up a lot as it is too restrictive if you plan on running it at higher RPM. The Brodak P-40 ARF is a very good design.
Pat Johnston knows what he is doing.