jaredyates
Member
Hi everyone, I'm building a Bearhawk with a Lycoming O360. The Bearhawk is an airplane that has a similar mission to a Maule or Husky. When it comes to props, Hartzell got together with Mark, the manufacturer of the kit and have recommended the HC-C2YR-1BF hub with F8477-4 blades. They also require a C1576 Damper on this combination of prop and engine.
I was planning to use an MT or Whirlwind prop, because the OEM price of the new Hartzell with the damper is about $8000, and the weight is 55 pounds. If I'm committed to buying new, I'd rather spend just a little bit more and get the Whirlwind, which I perceive to be of improved efficiency, performance, and reduced continuing maintenance cost. And, nobody else requires the damper.
Recently though, I found a slightly used 76" Hartzell that's for sale. It looks like it's in great shape with a non-AD hub and a compelling price. The only difference is that it comes with 7666A blades instead of the 8477-4 blades that Hartzell recommends. While I was doing a little bit more research, I started to gather the impression that the Hartzell with these 7666A blades don't need the heavy and expensive damper that the OEM configuration requires, and that made the whole package much more appealing.
So here's my question- is there a noticeable performance difference between the Hartzell 76" prop (7666) vs the 80" (8477) version? Husky provides both as an OEM option with their 360-powered airplanes. Maule sells their 360 powered airplanes with 7666 blades, and I suspect both of those manufacturers must have put some thought into that decision. Both props have almost the same hub (one is a C2YK and one is a C2YR), it's just the blades that are different.
My decision to avoid the Hartzell would be worth revisiting if I could pay less for it and fly safely without the damper (and it's associated weight and cost). I'm wondering if I would ever really notice a difference in performance between props with these two blades, and if I did, whether the extra $4000 in my (metaphorical) pocket might outweigh said observations. Having the best prop would be nice, but having the second best prop for half of the price would be nice too. At the same time, spending half as much on a prop that I'll hate forever isn't an effective allocation of resources.
Am I overlooking any other important differences between those blades other than their aerodynamic performance? Ground clearance is not an issue on the airplane. I posted the question to our Bearhawk-specific email group, and Gary suggested that I try here because prop gurus have been reported in the area.
I was planning to use an MT or Whirlwind prop, because the OEM price of the new Hartzell with the damper is about $8000, and the weight is 55 pounds. If I'm committed to buying new, I'd rather spend just a little bit more and get the Whirlwind, which I perceive to be of improved efficiency, performance, and reduced continuing maintenance cost. And, nobody else requires the damper.
Recently though, I found a slightly used 76" Hartzell that's for sale. It looks like it's in great shape with a non-AD hub and a compelling price. The only difference is that it comes with 7666A blades instead of the 8477-4 blades that Hartzell recommends. While I was doing a little bit more research, I started to gather the impression that the Hartzell with these 7666A blades don't need the heavy and expensive damper that the OEM configuration requires, and that made the whole package much more appealing.
So here's my question- is there a noticeable performance difference between the Hartzell 76" prop (7666) vs the 80" (8477) version? Husky provides both as an OEM option with their 360-powered airplanes. Maule sells their 360 powered airplanes with 7666 blades, and I suspect both of those manufacturers must have put some thought into that decision. Both props have almost the same hub (one is a C2YK and one is a C2YR), it's just the blades that are different.
My decision to avoid the Hartzell would be worth revisiting if I could pay less for it and fly safely without the damper (and it's associated weight and cost). I'm wondering if I would ever really notice a difference in performance between props with these two blades, and if I did, whether the extra $4000 in my (metaphorical) pocket might outweigh said observations. Having the best prop would be nice, but having the second best prop for half of the price would be nice too. At the same time, spending half as much on a prop that I'll hate forever isn't an effective allocation of resources.
Am I overlooking any other important differences between those blades other than their aerodynamic performance? Ground clearance is not an issue on the airplane. I posted the question to our Bearhawk-specific email group, and Gary suggested that I try here because prop gurus have been reported in the area.
