Hi all - I have what I hope is not a stupid question

I have a Great Planes AT-6 Texan ARF that I am in the final
stages of construction - I am attempting to install a Magnum XL .46
with a Pitts muffler. I have installed the motor mount and drilled the
mounting holes 4 1/2 in from the firewall as suggested by the manual.

Unfortunatly this does not allow my pitts muffler to fit and leaves
the cylinder head extremely close to the plywood cowl mount.

I have experimented and have found that if the engine is aprox 5in
from the firewall I have an adaquate amount of room. My question is what
(if anything) will this do to flight performance or safety? I posed this question
to GP's customer service and their advice was go out and buy a slimline
sports muffler - yeah great except I have already forked over 40 clams for my existing pitts ! Will the 1/2 in really mess up anything or do I have
to go spend yet more money ?

Any of you warbird fanatics have any good tips regarding this kit - specificly
with regards to making it just a wee bit more scale ( I have already done a job
on the instrument panel - and installed a rear one too ) as well as improving a
little on the ( somewhat lame ) decals and covering job. I would also be
interested in any feedback re flight characteristics ( FYI this is my 3rd plane
but my 1st warbird and low wing aircraft ) Thanks

Christopher

Sadly, T-6s are short-lived. Generally evil handlers. Very sensitive to aft c.g.s. Moving the motor forward can't hurt.
Watch the elevator deflections. Too much causes snap-rolls on takeoffs. Not enough causes very hard landings. Worst of both worlds!

Thank you - I didn't think the 1/2 in would make much diff except move
the ammount of weight in the tail - Thanks for the tip on the Elevator - Yeah
snap rolls on takeoff - nasty - I will set the rates exactly as stated in the manual
and see what happens !

The 1" forwad will change the CG and make the plane more nose heavy. If you have weight in the tail section you might be able to remove it. As long as the CG is where the plans or instructions call for you should be OK. You have probably thought about fitting the cowl already but if not consider what to do before you decide on anything.

Boy are you right on about the AT-6 elevator sensitivity
Deep sixed my H9 AT-6 on takeoff (snap roll to death)

Snapped my GP T-6 during test op flight never got to enjoy it. CG was set to spec w/ a O.S. 52 Surpass in the nose (it was about 3/4" forward). The club expert said I had too much elevator throw. Watch your control settings and keep them MILD as possible.

Oww [&o] No consolation I know but i've fixed worse!

I have decided after the expert advice here to get a low
wing trainer 1st prior to destroying my baby in the 1st
30 seconds and get good prior to joining the "warbird
club" besides it looks better hanging from my workshop
ceiling than in little pieces on my workbench!