Comment

Comment by Bob Simmons on August 20, 2009 at 7:19pm

I consider the leading edge reinforcement to be mandatory for me.

Thanks for that info, Donnie. That isn't the only issue the Aussies had with the Warp Drive, but it seems a hub redesign rectified that problem. You can see all their ADs for the Warp Drive here:
http://www.auf.asn.au/airworthiness/index.html#warpdrive

Comment by Russ Bens on August 20, 2009 at 3:19pm

I'm happy with my Sensenich GA prop. Recently, I increased the attack angle by about a degree for better cruise performance and to better fit within the desired RPM range. I do recommend the nickel reinforced leading edge, especially for the 750 where FOD is a bigger issue.

Comment by Donnie Moore on August 20, 2009 at 12:00pm

I don't know what happened to the link. ???

http://www.ultralightnews.ca/advisories1/warpdrivepropfailure2.htm

Comment by Donnie Moore on August 20, 2009 at 11:58am

Going with the Sensenich Ground adjustable. Thought about Warp drive because it's half the price, but I heard somewhere that they don't do well on direct drive motors. So I did some research to see if it was rumor or not and found this. Still haven't found anything from an official government site about the AD, but I feel the linked site is more reliable that comments on the forums.
You'll have to decide for yourself.

Roger got back to me and said he lost 7 mph with the larger tires with the O-200.

Comment by Bob Simmons on August 19, 2009 at 8:43am

By the way Donnie, what ground adjustable prop did you get? I'd prefer not to have wood. I was hoping for aluminum, but I've resigned myself to the fact that I'll likely have to settle for composite with a metal leading edge. That's all I've been able to find so far that might be suitable, most likely a Sensinich or Warp Drive. Whirlwind also makes a ground adjustable composite prop for J3300s, but it's 65" diameter. I'm not sure yet how well that might work.

Comment by Bob Simmons on August 19, 2009 at 8:16am

Actually, I was referring to IAS. We indicated 93 to 96 on the GPS on both of my flights with the O-200, so I'd still like to see more with the Jabiru. But like you said, all other factors are not the same anymore. Both of my flights were with the smaller tires and the three blade Warp Drive prop. Technically a three blade prop should be better for climb and not cruise, but there are too many other variables at play. I'm not really worried. I'm sure they're still tweaking things, and the final numbers will be better. Even if they aren't, I'm still going with the Jabiru. Six cylinders are so much smoother than four, especially at idle power. They've actually had stress issues with some 701 tails that many attributed at least partially to the vibrations inherent in the four cylinder engines installed. Not serious problems mind you, but it does highlight how a smoother engine can be better for more than just aesthetics.

Comment by Donnie Moore on August 17, 2009 at 6:23pm

Also have to remember that that is with the larger tires. The performance numbers put out for the O-200 were with the smaller tires. Not sure how much extra drag that added. Also the numbers put out for the O-200 were calibrated for standard conditions at Sea Level. I'm pretty sure the numbers Roger gave me are still raw numbers he's seeing in the cockpit, and with the heat and humidity that we had at the time I talked to Roger that 90 IAS would be closer to 94 TAS.
And still getting 800fps with these temps and humidity would indicate that they are pitched more for climb. Which is what I would expect them to do with the extra horses from the Jab since STOL is their big selling point.

I expect all these numbers will go up as the conditions get closer to standard.

Still I'm just going to go with the ground adjustable and play around with the settings until I find what works best for me. I guess in the end we will each have to figure out which will work best for our own situations.

Comment by Bob Simmons on August 17, 2009 at 12:13pm

That's what I'm hoping for. I figured it would go up. I'm just waiting to see how much. Thanks.

Comment by Russ Bens on August 17, 2009 at 10:52am

More information is needed on the RPM range that they are getting with the fixed pitch prop that is stock with that kit. I gained about 5 kts. cruise on my 601 after properly setting prop pitch. The Jabiru 3300 manual goes into detail about prop selection:

"All propellers must be able to obtain 2750 rpm static and 3150 rpm to 3300 rpm wide open
throttle straight and level."

Comment by Bob Simmons on August 17, 2009 at 10:10am

Hmm. 90 MPH cruise is a bit slower than the O-200. I hope that changes.

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