If it will hold up to the short stroke engine, I'd think it would be okay with the long stroke.  There isn't too much difference in speed, maybe 5-8mph tops.</p>

The only reason I brought up the my wing question...  Was I've seen 2 foam/balsa wings buckle under compression (many years ago of course). Both wings had a 3/16 wide plywood spar on it's edge, about 20" long layed down in the wing like you did your carbon thing.  And carbon laminent under the skins along the spar line, all the way out to the tops.  Both wings failed on the edge of where that spar ended, out by where the ailerons are.  And both wings had 3/32 top sheeting, and 1/6" bottom.   It could of been a bad build job, who knows?  more of an observation..</p>

looks good sir..</p>

RB </p>