crooked firewall
 

I am building Hangar 9 P51 Mustang 60 size which is an ARFwith saito 100 engine, just recently realized firewall is not perfectly sitting in front of the plane at 90 degree angel it is slightly crooked, therefore when I mount the engine , it is not mounting perfectly straight on the engine mounts,it is tilted to the side a bit.

is there any suggestions for a quick fix? will it effect the performance and trim?

crooked firewall
 

this is for a reason - its called right thrust , for when you take off at full throttle it helps to keep the plane straight, or to counter balance prop thrust, best

crooked firewall
 

so it is normal thx a lot I did not know,when you look at the plane from above engine is sitting slightly to the right.

crooked firewall
 

Lot's of kits /planes have 1 or 2 degrees of right thrust builtin, for the reason mentioned above.

So it's normal. Perhaps this is your first "bigger" plane, where it is more obvious. Also, the bigger the plane, the bigger the engine, the more prop effect you will have, so the right thrust becomes more important as the planes go up in size


(small kits or trainer will not have this right thrust as the prop effect is far less noticable)

crooked firewall
 

Mount your engine to the left side of the firewall (left side looking at it from the cockpit) just enough so that the prop shaft is centered with the cowl opening. It will still be pointing to the right which is good, but will look much better being centered.

Good luck!

crooked firewall
 

If you look closely, you will probably also see down thrust built in. This is usually required, especially on high winged aircraft like most trainers are.