dicel87
Active Member
Just need to get smarter on something I've wondered as I read the various homebuilding sites around the internet.
When someone wants to use an engine on a plane that is different than the one that the designer originally used for the plane, how do they determine that it is feasible in terms of maintaining acceptable CG? (making assumptions that the HP is in the right range, it fits in the cowl, etc...)
For example, if the engine in the original design weighs 250 lbs and someone wants to install an engine that weighs only 200 lbs is it simply a matter of determining how much more forward the new engine must be installed in order to make the calculations work? Or do you attempt to maintain the same mounting position but compensate the decreased weight with a heavy prop, battery or other accessories moved forward, etc... in order to make the numbers work?
The most recent real world example I ran across was a Viking engine (Honda Fit modified) being installed in an RV-9A. I believe the original RV-9A flew on a Lycoming O-235 which, from what I've read, is 40-50 pounds heavier than the Viking engine.
Just wondering how all that works.
Thanks
When someone wants to use an engine on a plane that is different than the one that the designer originally used for the plane, how do they determine that it is feasible in terms of maintaining acceptable CG? (making assumptions that the HP is in the right range, it fits in the cowl, etc...)
For example, if the engine in the original design weighs 250 lbs and someone wants to install an engine that weighs only 200 lbs is it simply a matter of determining how much more forward the new engine must be installed in order to make the calculations work? Or do you attempt to maintain the same mounting position but compensate the decreased weight with a heavy prop, battery or other accessories moved forward, etc... in order to make the numbers work?
The most recent real world example I ran across was a Viking engine (Honda Fit modified) being installed in an RV-9A. I believe the original RV-9A flew on a Lycoming O-235 which, from what I've read, is 40-50 pounds heavier than the Viking engine.
Just wondering how all that works.
Thanks
