ORIGINAL: jeffie8696
What affect if any would be to raising the engine mount flightly on the firewall? Not by a lot , perhaps a half inch.
It would place it slightly above the original thrust centerline.
Would the plane fly nose heavy or tail heavy? Anything else?
High wing .40 size trainer.
So you think it would cause the plane to want to pitch down under power if it was set higher? Much like increasing the down thrust.
Besides the possibility of creating the fuel problem explained above, relocating the engine higher will reduce a little the pitch up related to full throttle.
The balance will not be affected.
If you want to keep exactly the same pitch reaction with full throttle of the original design, you could add a 1/20" shim to the bottom of the engine mount.
A couple of 1/16" thick washers will do it.
Check the schematic and adjust the dimensions to your trainer, if they are very different.