---------------------------------------------------------- TeamGrumman-List Digest Archive --- Total Messages Posted Fri 03/12/04: 7 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:20 AM - Fw: MT Prop (Ned Thomas) 2. 06:33 AM - Re: Fw: MT Prop (Robinson Charles Col AAC/XP) 3. 07:27 AM - Re: MT Props (flyv35b) 4. 09:44 AM - Re: MT Props (TeamGrumman@aol.com) 5. 09:46 AM - Re: MT Props (TeamGrumman@aol.com) 6. 09:51 AM - Re: MT Props (TeamGrumman@aol.com) 7. 12:23 PM - Re: MT Props (flyv35b) ________________________________ Message 1 _____________________________________ Time: 06:20:58 AM PST US From: "Ned Thomas" <315@cox.net> Subject: TeamGrumman-List: Fw: MT Prop --> TeamGrumman-List message posted by: "Ned Thomas" <315@cox.net> ----- Original Message ----- From: "Lawrence M. Burrell Jr." Subject: Re: MT Prop > My aerobatic competitor friends tell me their MT props are at risk of damage > if flown in the rain. Is that true with this prop? > Skip > Lawrence M. Burrell, Jr. > 2880 S. E. Downwinds Road > Jupiter, Fl., 33478 > 561/747-5705 > Fax 747-0352 > e-mail: info@lmburrell.com > ----- Original Message ----- > From: "Ned Thomas" <315@cox.net> > To: > Sent: Thursday, March 11, 2004 9:49 PM > Subject: MT Prop > > > > Will someone inform Bill Scott and whoever else is interested on gg that I > > have installed an MT prop on a Tiger and it's awesome. Also, as for MT > prop > > being untested or something to that implication, MT has a lot better track > > record than domestic CS Prop manufactures. > > > > The MT prop is a lot better deal than adding a hollow crank and mechanical > > prop to an A4K. > > > > Gary > > > ________________________________ Message 2 _____________________________________ Time: 06:33:50 AM PST US From: Robinson Charles Col AAC/XP Subject: RE: TeamGrumman-List: Fw: MT Prop --> TeamGrumman-List message posted by: Robinson Charles Col AAC/XP > My aerobatic competitor friends tell me their MT props are at risk of damage > if flown in the rain. Is that true with this prop? > Skip > Lawrence M. Burrell, Jr. Depends on which one, I believe. The early ones had some issues, but since then, all the MT props have been through the ice/bird certification process and passed. I was looking at a 3-blade, MT-9V off an Extra 300L, for use on an Express. A prop shop in CA has one for $5800 or so. Also, the initial MT prop/engine combinations had low TBO limits. Most of those have been moved back into the 1200-2000 hour range as they have more data on vibration effects. About the only ADs I've found on the props have to do with the lag bolts that hold the props to the center assembly and the laminate that covers the steel abrasion shield (have to inspect to ensure no peeling/chips/cracks). If the kit I bought to complete didn't already have a Hartzell Q-Tip installed, I would have bought the MT-9V as it's a lot less weight and supposedly better performance. Chuck ________________________________ Message 3 _____________________________________ Time: 07:27:17 AM PST US From: "flyv35b" Subject: Re: TeamGrumman-List: MT Props --> TeamGrumman-List message posted by: "flyv35b" > I am looking at results from a test that Van's conducted on props. It is in > the Fifth issue 2003 RVator. Page 6 tabulates the results. The slowest > constant speed prop was 200.7 mph the fastest constant speed prop was 208.9 > mph. I would not call 8.2 mph "considerable." Do you? Perhaps you have some > other test data from Van's? Ned, I don't want to throw water on your fire but if I were deciding on which prop to purchase I certainly would look at an 8 mph difference in speed as a "considerable" (well worth considering) difference. It would take a large increase in engine size to equal that much speed! There would have to be other large benefits with the slower prop to choose it. > They tested and compared only one parameter, Optimum Cruise speed defined as > 75% power at 8000 feet for the O360 engine. They did not compare or test > climb performance. However, from the incomplete climb rate data that was > collected climb rate variations were on the order of 2 - 5%. Yes, they purposely chose those conditions as that is where most planes spend the vast majority of their time and RV's have such great climb rates anyhow that any of the props would work fine. Also, it is much more difficult to measure ROC and compare one prop to another. I know of 2 homebuilts with MT props that had problems and the props had to be sent back to the distributor on the east coast and then back to Germany for repair. It took several months to get them back. With their high price and serviceability limitations I'd have to think long and hard before I put a MT prop on any plane. But in your case you don't have any other choice at this point other than doing what Bill Scott is proposing, and that certainly wouldn't be easy or cheap. How much exactly is the cost of the MT prop for the Tiger? > Looking forward to trying out the MT on my Tiger. > Ned I wish you a successful outcome. Gary seems to think it is pretty great. And he has more experience with it on a Tiger than anyone else that I know ( other than the owner). It would be nice to get some real UNBIASED speed performance comparison with the fixed pitch Sensenich on the SAME plane. Cliff ----- Original Message ----- From: "Ned Thomas" <315@cox.net> Subject: Re: TeamGrumman-List: MT Props > --> TeamGrumman-List message posted by: "Ned Thomas" <315@cox.net> > > Cliff, > > I am looking at results from a test that Van's conducted on props. It is in > the Fifth issue 2003 RVator. Page 6 tabulates the results. The slowest > constant speed prop was 200.7 mph the fastest constant speed prop was 208.9 > mph. I would not call 8.2 mph "considerable." Do you? Perhaps you have some > other test data from Van's? > > They tested and compared only one parameter, Optimum Cruise speed defined as > 75% power at 8000 feet for the O360 engine. They did not compare or test > climb performance. However, from the incomplete climb rate data that was > collected climb rate variations were on the order of 2 - 5%. > > Looking forward to trying out the MT on my Tiger. > Ned > > ----- Original Message ----- > From: "flyv35b" > To: > Subject: Re: TeamGrumman-List: MT Props > > > > --> TeamGrumman-List message posted by: "flyv35b" > > > > > I didn't think your first report sounded quite that good, possibly due to > > the 2500 rpm limitation. > > > > The MT prop that Van's aircraft tested on an RV-8 not long ago was > > considerably slower than the new Hartzell blended airfoil prop and the > > Sensenich fixed pitch prop for that matter. > > > > Cliff > > ----- Original Message ----- > > From: > > To: > > Subject: TeamGrumman-List: MT Props > > > > > > > --> TeamGrumman-List message posted by: TeamGrumman@aol.com > > > > > > Will someone inform Bill Scott and whoever else is interested on gg that > I > > > have installed an MT prop on a Tiger and it's awesome. Also, as for MT > > prop > > > being untested or something to that implication, MT has a lot better > track > > > record than domestic CS Prop manufactures. > > > > > > The MT prop is a lot better deal than adding a hollow crank and > mechanical > > > prop to an A4K. > > > > > > Gary > > > > > > > > > > > > ________________________________ Message 4 _____________________________________ Time: 09:44:48 AM PST US From: TeamGrumman@aol.com Subject: Re: TeamGrumman-List: MT Props --> TeamGrumman-List message posted by: TeamGrumman@aol.com In a message dated 03/11/04 07:05:02 PM, flyv35b@ashcreekwireless.com writes: > The MT prop that Van's aircraft tested on an RV-8 not long ago was > considerably slower than the new Hartzell blended airfoil prop and the > Sensenich fixed pitch prop for that matter. > And here is the crux of the matter. The MT prop uses a very dated airfoil. The new airfoils are a lot better. However, what Bill Scott was proposing, as I understand it, is using the old style Hartzell prop on the Tiger. Not sure if that would help much. Now, if the NEW STCd props from Hartzell could be used, now you're talkin' ________________________________ Message 5 _____________________________________ Time: 09:46:21 AM PST US From: TeamGrumman@aol.com Subject: Re: TeamGrumman-List: MT Props --> TeamGrumman-List message posted by: TeamGrumman@aol.com In a message dated 03/11/04 06:49:37 PM, 315@cox.net writes: > You had mentioned something about MT might allow the ontroller to be > modified so that it will govern at 2700 RPM instead of 2500 RPM. Do you have > anymore information about this? > Thanks, > Ned > No, not really. You can manually select any rpm you like and fly the plane as if it had a variable fixed pitch. If enough pressure were put on MT, they might change the rpm limitations on their controller. But I doubt it. Gary ________________________________ Message 6 _____________________________________ Time: 09:51:29 AM PST US From: TeamGrumman@aol.com Subject: Re: TeamGrumman-List: MT Props --> TeamGrumman-List message posted by: TeamGrumman@aol.com In a message dated 03/11/04 06:41:26 PM, gilalex@earthlink.net writes: > Gary... did you finally see a cruise speed increase, or is all of the gain > in climb rate?? > On the two days that I flew the plane with the MT Prop, the weather was horrible. Low clouds, wind and rain. The ceiling was 5500 feet. Lots of turbulence too. My best guess at a True Air Speed was around 136 knots turning about 2500 rpm. For me? that's too slow for $15,000. My offer still holds, "You pay for all the hardware and I'll put an IO360B1E into your plane for no labor cost." I get the STC. Odds are you'll be flying an experimental for 5 years.... Or be patient, I might get my own Tiger and do it myself. Gary ________________________________ Message 7 _____________________________________ Time: 12:23:23 PM PST US From: "flyv35b" Subject: Re: TeamGrumman-List: MT Props --> TeamGrumman-List message posted by: "flyv35b" > And here is the crux of the matter. The MT prop uses a very dated airfoil. > The new airfoils are a lot better. However, what Bill Scott was proposing, > as I understand it, is using the old style Hartzell prop on the Tiger. Not > sure if that would help much. Now, if the NEW STCd props from Hartzell could > be used, now you're talkin' And why not? Since you would be getting an STC, use any prop you want. But why not use the new blended airfoil prop that Hartzell supplies to Van's right now for the O-360 A1A engine? They have already done stress and vibration testing to my knowledge. Speaking of price, I see NO reason why the MT prop has to cost so much money. From what I know it is over $11,000 with spinner and maybe more. I recently bought a new 82 in. diameter 3 blade (no less) Hartzell, blended airfoil Super Scimitar prop for my Bonanza for $7900, including air freight shipping from OH and the STC! I'll bet you can buy the 2 blade model for your RV from Van's for less than $7000. Cliff A&P/IA ----- Original Message ----- From: Subject: Re: TeamGrumman-List: MT Props > --> TeamGrumman-List message posted by: TeamGrumman@aol.com > > > In a message dated 03/11/04 07:05:02 PM, flyv35b@ashcreekwireless.com writes: > > > > The MT prop that Van's aircraft tested on an RV-8 not long ago was > > considerably slower than the new Hartzell blended airfoil prop and the > > Sensenich fixed pitch prop for that matter. > > > > And here is the crux of the matter. The MT prop uses a very dated airfoil. > The new airfoils are a lot better. However, what Bill Scott was proposing, > as I understand it, is using the old style Hartzell prop on the Tiger. Not > sure if that would help much. Now, if the NEW STCd props from Hartzell could > be used, now you're talkin' > >