---------------------------------------------------------- Rocket-List Digest Archive --- Total Messages Posted Sun 02/08/04: 4 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 01:04 AM - Interesting prop story (f1rocket@telus.net) 2. 07:33 AM - Re: Interesting prop story (Bob Japundza) 3. 09:28 AM - Re: Interesting prop story (Phil Smith) 4. 04:39 PM - Re: Interesting prop story (LesDrag@aol.com) ________________________________ Message 1 _____________________________________ Time: 01:04:22 AM PST US From: f1rocket@telus.net Subject: Rocket-List: Interesting prop story --> Rocket-List message posted by: f1rocket@telus.net Hi all. While investigating which propeller to put on the rocket I sent AeroComposites a letter asking which prop would be best for the rocket. In the e-mail discussion I received this interesting story from them, and maybe someone out there can actually verify it? Quoting Harry Griswold from AeroComposites: "The performance of our propleller on the RV8 (IO-360 engine, 220 hp, Sam James Cowl) is outstanding and in one recorded instance pulled away from and F1 Rocket (friend flying side by side) with the IO-540 engine." I then asked for some more details about which prop etc. and received the following: "I will reconfirm the details of the RV8 "fly-off" with the F1 Rocket run. The RV8 had one of our 2-bladed propellers. I am not sure what the F1 Rocket had for a propeller. The tes results are an indicaiton of our propellers performance although the test is not a quantative and controlled test. In the absence of good comparative test results (2-bladed vs 3-bladed) for our propellers, we would recommend the 3-bladed for excellent overall performance (climb, cruise). However, the 2-bladed propeller might have a bit faster top end cruise speed. We will be publishing some RV8 test results on our web site very soon, to be followed with a more detailed discussion of propeller testing/performance by late January." I see now on the web site they are saying February. It's an interesting story, and maybe someone out there has more details? Thanks, Jeff F1 #119- right wing done (except flap mounting), empenage done, ready to finish left wing, fuse needs engine mount/gear next. ________________________________ Message 2 _____________________________________ Time: 07:33:14 AM PST US From: Bob Japundza Subject: Re: Rocket-List: Interesting prop story --> Rocket-List message posted by: Bob Japundza hehehe...they didn't mention the Rocket was flying at 50% power :) The guy who owns this RV-8 has been claiming he could outrun a Rocket and likes to boast about "no rocket guy wants to race me". Funny that at the Sun N Fun race last year he got whipped by a stock HR2 and an F1 running at 2500rpm and missing some fairings... It seems that guys running their mouths help sell pricey props. Regards, Bob RV-6 flying, F1 under const. f1rocket@telus.net wrote: Quoting Harry Griswold from AeroComposites: "The performance of our propleller on the RV8 (IO-360 engine, 220 hp, Sam James Cowl) is outstanding and in one recorded instance pulled away from and F1 Rocket (friend flying side by side) with the IO-540 engine." I then asked for some more details about which prop etc. and received the following: "I will reconfirm the details of the RV8 "fly-off" with the F1 Rocket run. The RV8 had one of our 2-bladed propellers. I am not sure what the F1 Rocket had for a propeller. The tes results are an indicaiton of our propellers performance although the test is not a quantative and controlled test. In the absence of good comparative test results (2-bladed vs 3-bladed) for our propellers, we would recommend the 3-bladed for excellent overall performance (climb, cruise). However, the 2-bladed propeller might have a bit faster top end cruise speed. --------------------------------- ________________________________ Message 3 _____________________________________ Time: 09:28:04 AM PST US From: "Phil Smith" Subject: RE: Rocket-List: Interesting prop story --> Rocket-List message posted by: "Phil Smith" In the last issue of RVator, the Hartzell blended airfoil was fastest, followed by the normal Hartzell prop that Van's sells. The aero composite was somewhat slower. The article tested about 8 different props on what was claimed as two very similar RV-8's. If anyone is interested, I can dig up the article and try to summarize it. -----Original Message----- From: owner-rocket-list-server@matronics.com [mailto:owner-rocket-list-server@matronics.com] On Behalf Of f1rocket@telus.net Subject: Rocket-List: Interesting prop story --> Rocket-List message posted by: f1rocket@telus.net Hi all. While investigating which propeller to put on the rocket I sent AeroComposites a letter asking which prop would be best for the rocket. In the e-mail discussion I received this interesting story from them, and maybe someone out there can actually verify it? Quoting Harry Griswold from AeroComposites: "The performance of our propleller on the RV8 (IO-360 engine, 220 hp, Sam James Cowl) is outstanding and in one recorded instance pulled away from and F1 Rocket (friend flying side by side) with the IO-540 engine." I then asked for some more details about which prop etc. and received the following: "I will reconfirm the details of the RV8 "fly-off" with the F1 Rocket run. The RV8 had one of our 2-bladed propellers. I am not sure what the F1 Rocket had for a propeller. The tes results are an indicaiton of our propellers performance although the test is not a quantative and controlled test. In the absence of good comparative test results (2-bladed vs 3-bladed) for our propellers, we would recommend the 3-bladed for excellent overall performance (climb, cruise). However, the 2-bladed propeller might have a bit faster top end cruise speed. We will be publishing some RV8 test results on our web site very soon, to be followed with a more detailed discussion of propeller testing/performance by late January." I see now on the web site they are saying February. It's an interesting story, and maybe someone out there has more details? Thanks, Jeff F1 #119- right wing done (except flap mounting), empenage done, ready to finish left wing, fuse needs engine mount/gear next. == == == == ________________________________ Message 4 _____________________________________ Time: 04:39:43 PM PST US From: LesDrag@aol.com Subject: Re: Rocket-List: Interesting prop story --> Rocket-List message posted by: LesDrag@aol.com Why 2500 RPM? That was the question I had after reading Van's propeller comparison on a Lycoming 360 engine. The Lycoming power chart list manifold pressure and RPM for 55%, 65% and 75% power. The RPM's given are from 2100 to 2400 RPM. There were not any power settings provided for 2500 RPM. Of course, on the Lycoming 360 engine with a non counterweighted crankshaft, MOST CS propellers have a RPM restriction between 2000 to 2300 RPM. So that would leave 2300 and 2400 RPM as reasonable choices. Jim Ayers