engine aplication?
 

Hey guy's, I am building a Greatplanes learjet and need to know if my engine choice is way out of line. The manafacture says that it requires a .40 to .50 size Two stroke. I have an OS .61FX that is in need of a home and thought that this would be a good place for it.
I know that this is outside of the scope that the kit calls for but I plan on sheeting the entire plane so my thought is that with the overall weight of the plane the extra power could come in handy.
One thing that concerns me is that the engine mount for the .61FX darn near takes up the entire firewall so reinforcing would without a doubt need to be done.
Any thoughts/advice/other on this?
Thank you, Marco.

RE: engine aplication?
 

I have never gone wrong using the 50% rule. If the they say the plane is a 60 size I use a 90, 40 size I use a 60.
I always use some fibre glass to reinforce the firewall to wing seat and I make sure the air frame is strong enough for the greater vibration and torque.