Greetings,
I've been working on a Predator 670 that could be used for a 1/2 VW replacement, but it's still going to be heavier than it needs to be for nearly any legal part 103 design. Maximum weight reduction and no electric starter might get you in the mid to upper 70 lb range with a redrive. I'm certain you can get 40 HP out of one though. If my Ace redrive ever shows up, maybe I'll find out how it runs.
What I'm thinking about is a lighter option that would still get 30 HP. A smaller v-twin would be nice, but more likely this will end up being a single cylinder, and either way it will need availability of aftermarket performance parts. It sounds like a lot of these are Honda clones, from the GX340-390 range. I've seen the Predator 420, and Duromax 440 mentioned. Those are typically 13-15 HP stock, so 30 HP is probably possible at higher RPM with the right parts.
One off-the-shelf option seems to be the ThumpAir 460 that seems to be sold though Badland Aircraft, which is likely the plane I'll be building. it does seem hard to imagine 38 HP from 460 cc, though I believe there are a few of these flying now. https://www.badlandaircraft.com/product/thumpair/
What would be the best engine to consider for a DIY conversion? It needs to have performance parts available, so likely something that's already in use for other vehicle types.
Thanks,
Rusty
I've been working on a Predator 670 that could be used for a 1/2 VW replacement, but it's still going to be heavier than it needs to be for nearly any legal part 103 design. Maximum weight reduction and no electric starter might get you in the mid to upper 70 lb range with a redrive. I'm certain you can get 40 HP out of one though. If my Ace redrive ever shows up, maybe I'll find out how it runs.
What I'm thinking about is a lighter option that would still get 30 HP. A smaller v-twin would be nice, but more likely this will end up being a single cylinder, and either way it will need availability of aftermarket performance parts. It sounds like a lot of these are Honda clones, from the GX340-390 range. I've seen the Predator 420, and Duromax 440 mentioned. Those are typically 13-15 HP stock, so 30 HP is probably possible at higher RPM with the right parts.
One off-the-shelf option seems to be the ThumpAir 460 that seems to be sold though Badland Aircraft, which is likely the plane I'll be building. it does seem hard to imagine 38 HP from 460 cc, though I believe there are a few of these flying now. https://www.badlandaircraft.com/product/thumpair/
What would be the best engine to consider for a DIY conversion? It needs to have performance parts available, so likely something that's already in use for other vehicle types.
Thanks,
Rusty
