John,

I think there might indeed be a little confusion going on. First, are we strictly talking about the LDIII or about your ordered plans in general?

It might be best if you provide some specs on the model as I have no idea of what we are talking about other than knowing the name Loaded Dice.

Other than that though, I'd say that modern 2x2 pattern planes which are ~75-78" in span/length are by en large designed for either electric power or large 4 strokes notably YS DZ 160's and 170's (1.6 or 1.7 cu in.) Classic pattern planes are considerably smaller with wing spans typically in the 65-69" span range. Engines for these models would be smaller typically for 0.6 two strokes or 1.2 four strokes max. Typical SPA planes fly with 0.9 4 strokes on their silencers (i.e., no pipes) while BPA/CPA planes are more typically powered with piped 0.6's and retracts.

Post a snap of the plan we're talking about, provide a link to it and/or post some specs and we'll be able to better settle this. In a nutshell though, models need to be powered appropriately for their size regardless of type of power and/or exhaust system. A model that needs a 0.6 cu in 2 stroke engine will fly with or without a pipe. This last is a builder's choice as would be the use of a 0.9 4 stroke without a pipe. Either one will generate comparable power as would 1400W of electric power.

David.