---------------------------------------------------------- Rocket-List Digest Archive --- Total Messages Posted Fri 05/13/11: 4 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:03 AM - Re: Best Prop for HR 2 (n395v) 2. 06:27 AM - Re: Re: Best Prop for HR 2 (Stuart Hutchison) 3. 07:45 AM - Re: Re: Best Prop for HR 2 (Rob Ray) 4. 02:43 PM - Re: Re: Best Prop for HR 2 (Tom Gummo) ________________________________ Message 1 _____________________________________ Time: 06:03:54 AM PST US Subject: Rocket-List: Re: Best Prop for HR 2 From: "n395v" I can't speak for a Harmon Rocket but a lot of F1s had a terrible vibration (prop-beat or whatever) that was intolerable with a 2 blade hartzell. Mine was one of them. Changed to a 3 blade MT (one of Jim's) Problem was gone and plane was much quieter. It did however have measurable loss of performance in climb and cruise as well as top speed. I think Tom Gummo has a 4 blade MT on his Harmon and I recall somewhere he called it the slowest Rocket in the West. In my opinion the less blades the better for performance and cost. As to the manufacturer I have heard few complaints about Hartzell or MT. Never heard of the brand you are considering. -------- Milt Read this topic online here: http://forums.matronics.com/viewtopic.php?p=339741#339741 ________________________________ Message 2 _____________________________________ Time: 06:27:25 AM PST US From: Stuart Hutchison Subject: Re: Rocket-List: Re: Best Prop for HR 2 Should have better climb on 3 blades, but lower top speed (extra blade = more drag). 2 for go, 3 for show! Kind regards, Stu www.mykitlog.com/rockfly Sent from my iPhone On 13/05/2011, at 11:01 PM, "n395v" wrote: > > I can't speak for a Harmon Rocket but a lot of F1s had a terrible vibration (prop-beat or whatever) that was intolerable with a 2 blade hartzell. Mine was one of them. Changed to a 3 blade MT (one of Jim's) > > Problem was gone and plane was much quieter. It did however have measurable loss of performance in climb and cruise as well as top speed. > > I think Tom Gummo has a 4 blade MT on his Harmon and I recall somewhere he called it the slowest Rocket in the West. > > In my opinion the less blades the better for performance and cost. As to the manufacturer I have heard few complaints about Hartzell or MT. Never heard of the brand you are considering. > > -------- > Milt > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=339741#339741 > > > > > > > > > > > ________________________________ Message 3 _____________________________________ Time: 07:45:28 AM PST US From: Rob Ray Subject: Re: Rocket-List: Re: Best Prop for HR 2 Best HR2 prop? The one that works:) seriously, the prototype HR2 has a Hartzell 2 blade sold by John. After testing 2 props on mine and chatting with other folks, here is my 2cents. I had a "D" twist Hartzell 2 blade on mine optimized for 2500 RPM. Their is also a "J" twist optimized for 2350 RPM. Hartzell also makes a 2blade Blended airfoil prop for the Rocket currently flown by Tom Martin. The MT would be smoother but a bit slower at top end, the 3blade Hartzell is too heavy. I would either go with the J twist or BA 2 blade from Hartzell purchased through Harmon (J) or Team Rocket (BA) Smokey Sent from my iPhone On May 13, 2011, at 9:01, "n395v" wrote: > > I can't speak for a Harmon Rocket but a lot of F1s had a terrible vibration (prop-beat or whatever) that was intolerable with a 2 blade hartzell. Mine was one of them. Changed to a 3 blade MT (one of Jim's) > > Problem was gone and plane was much quieter. It did however have measurable loss of performance in climb and cruise as well as top speed. > > I think Tom Gummo has a 4 blade MT on his Harmon and I recall somewhere he called it the slowest Rocket in the West. > > In my opinion the less blades the better for performance and cost. As to the manufacturer I have heard few complaints about Hartzell or MT. Never heard of the brand you are considering. > > -------- > Milt > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=339741#339741 > > > > > > > > > > ________________________________ Message 4 _____________________________________ Time: 02:43:19 PM PST US From: "Tom Gummo" Subject: Re: Rocket-List: Re: Best Prop for HR 2 Guys, I also have a thirty year old engine that I rebuilt. IO-540J4A5 is only 250 HP as well. :-) So who knows what the real HP is? Jim tells me that I just don't have the HP to use my prop properly. Part of my slowest is that I built the plane myself and while it turned out great, I clearly didn't know anything about getting speed out of an aircraft. I didn't have an vibration when I had a two blade Hartzell. In my case, the three blade MT was as fast as the two blade Hartzell. My four blade MT is slower as I used to cruise: at 10,500 or 11,500 MSL Full throttle. RPM 2100 Leaned to 10.0 to 10.5 GPH KIAS = 140 True = 180 Knots with MT prop: KIAS = 135 True = 170 Knots For local flying, I really don't see much of a difference. Numbers are from the top of my head but they are close. Tom "GummiBear" Gummo Major USAF Retired, F-4G Wild Weasel Instructor Pilot Harmon Rocket II, N561FS, 390 hours of the biggest grin ----- Original Message ----- From: "n395v" Sent: Friday, May 13, 2011 6:01 AM Subject: Rocket-List: Re: Best Prop for HR 2 > > I can't speak for a Harmon Rocket but a lot of F1s had a terrible > vibration (prop-beat or whatever) that was intolerable with a 2 blade > hartzell. Mine was one of them. Changed to a 3 blade MT (one of Jim's) > > Problem was gone and plane was much quieter. It did however have > measurable loss of performance in climb and cruise as well as top speed. > > I think Tom Gummo has a 4 blade MT on his Harmon and I recall somewhere he > called it the slowest Rocket in the West. > > In my opinion the less blades the better for performance and cost. As to > the manufacturer I have heard few complaints about Hartzell or MT. Never > heard of the brand you are considering. > > -------- > Milt > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=339741#339741 > > > __________ Information from ESET NOD32 Antivirus, version of virus > signature database 6120 (20110513) __________ > > The message was checked by ESET NOD32 Antivirus. > > > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message rocket-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Rocket-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/rocket-list Browse Digests http://www.matronics.com/digest/rocket-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.