Curmudgeon in Training (CIT)
- Apr 13, 2009
- Warren, VT USA
Only one way to find out... math model for both on a fixed mission profile of your choice. You would break the NA 540 into mission chunks like climb, cruise, yadda and did individual estimates for fuel flow and HP at each altitude you could start to figure out time down range for each event and fuel flow during each segment. For each though you have to look at fuel consumed along the way and the original weight difference on MTOW between events. It really isn't all that bad of a spreadsheet. If you don't factor in the cost of the engine choice it would be an interesting operating cost and performance investigation on it's own. If you factor in lifcycle costs it is another animal altogether. But you knew all that. For a small plane that 540 is a big chunk of metal to both house and lift. Fortunately on a small airframe the lift part isn't as strong in the mix. You can fly a freight car if you have a high enough trust vector valueBack to the topic at hand- I'm looking at the typical overpowered two place design for my own needs. I have been going along the big inch NA powerplant (540 Lyc or V8) route so far. I wonder though, if you took something like a 300 HP Rocket and replaced the engine with a normalized 180, how it would perform?
As I sit in my fuselage mockup and ponder the V8 integration, I can't help but consider the 180 Lyc sitting in the corner. If I add a turbo, would I come out ahead...