Hatz Biplane Association

Though the R2800 is quite a bit heavier than the Jabiru 3300, isn't it safe to assume that (thanks to a much larger, slower prop) an R2800 Bantam would get better climb and density altitude performance?

Does anybody here have opinions regarding the R2800 on the Bantam airframe? Up here in Colorado, I'd be willing to trade some useful load for that extra bit of "oomf".

Nick

I share your interest in the Rotac option. But I winder if the 40 pound weight penalty and 10 HP loss would make it a viable option. Wonder if it has ever been done on the Bantam.

The original intent of the Bantam was to move weight forward to compensate for the lighter weight of the Jabiru. It just happened that all of the mods that moved the weight forward also reduced the overall weight of the aircraft. So, if you add a heavier engine you are effectively reversing it back to the CB-1 (originally based on a 100HP engine).

As far as all-up empty weight goes, yes. A Rotec might put the empty weight somewhere around 840-860. The biggest difference here from the CB-1 would be a bit of missing wing area, as the Bantam has a shorter span. This wing area difference is why I think the CB-1 comparison is unfair, even though the weights would be about the same.

On a side note, I'd like to point out that while the Rotec has less HP, it is capable of swinging a much larger prop than the Jabiru (and other engines in the HP and weight range) thanks to multiplied torque supplied by the gearbox, so I feel the HP comparison is also unfair.

The real question might be if the R2800 swinging that larger prop is efficient enough to overcome the loss of wing area as compared to, say, an O-200 powered CB-1 (in climb...I realize takeoff distance might be a bit longer regardless).

Might just be time to quit overthinking it and start saving for a Rotec (BIG goal).

Thanks for the input, guys!

Nick

Don't get me wrong -- I like the Rotec too (though I'm not sure I could bring myself to spending that kind of money for it) but isn't the whole point of the Bantam that it's an LSA-compliant aircraft? Won't the Rotec push it out-of-category? Functionally, I don't think the HP comparison is apropos as the gearbox should give you more torque, which is what drives the prop. Anyway, a Hatz isn't about Pitts/Skybolt performance... so I think the Rotec would be a fine choice. It does sound all the business, but I did notice it is a little fuel-hungry, or so it seemed. Generally the fewer cylinders the more efficient an engine is.