42" Boxxer
 

Just started to build a 42" boxxer biplane and would like some input for a engine and prop combo. I have a spare pro .46 Thunder Tiger engine and am wondering if that would be sufficient or should i go with a 72 four stroke or so???

RE: 42" Boxxer
 

Honestly, I think both of your suggested motors will be less than you need for good performance.

The OS .50SX, .55AX, Webra .50 or Irvine .53 would all be good choices. For 4 stroke power, I'd suggest the YS .63 or the Saito .82.

Prop choice depends entirely on the motor chosen.

RE: 42" Boxxer
 

Yep, what him said.