AmigOne Posted October 3, 2013 Report Posted October 3, 2013 I have read in some older postings in this and other forums that some owners were reporting up to 6 MPH increase and less vibration with climb performance unchanged in their M20C after changing to the Hartzell scimitar. Does anybody have a more recent experience with this propeller? Quote
Bob_Belville Posted October 3, 2013 Report Posted October 3, 2013 I have the scimitar prop on my E but do not have a "before" on the speed. TAS this morning @6000' was 154K @ 75% HP, ROP. I usually run at 2550 RPM and find it really smooth there. (On my IO360A1A the caution range is 2350-2550 when over 24" MAP.) I don't know if your O360 might be different. The STC for the prop advises slightly longer TO roll and slightly reduced climb. No mention is made of cruise speed. Quote
Shadrach Posted October 3, 2013 Report Posted October 3, 2013 I have the scimitar prop on my E but do not have a "before" on the speed. TAS this morning @6000' was 154K @ 75% HP, ROP. I usually run at 2550 RPM and find it really smooth there. (On my IO360A1A the caution range is 2350-2550 when over 24" MAP.) I don't know if your O360 might be different. The STC for the prop advises slightly longer TO roll and slightly reduced climb. No mention is made of cruise speed. Weird... The "No continuous operation in this range" listed in the F POH is 2150 to 2350RPM. 2350 to 2500RPM is the "recommended operating range" and 2500 to 2700RPM is the "Rated operating range" (whatever that means...). Is your ops range due to the new prop? I'm beginning to wonder if the factory didn't "just make things up" as they went along... I don't really believe that, but their paperwork and POHs from the 60s and 70s is just lousy... There are numerous and awful typos in my 67 POH... Quote
Bob_Belville Posted October 3, 2013 Report Posted October 3, 2013 Weird... The "No continuous operation in this range" listed in the F POH is 2150 to 2350RPM. 2350 to 2500RPM is the "recommended operating range" and 2500 to 2700RPM is the "Rated operating range" (whatever that means...). Is your ops range due to the new prop? I'm beginning to wonder if the factory didn't "just make things up" as they went along... I don't really believe that, but their paperwork and POHs from the 60s and 70s is just lousy... There are numerous and awful typos in my 67 POH... http://www.hartzellprop.com/top_prop_details.php?id=104 Ross, Read it again. The 2350-2550, over 24" applies to Es & Fs only. Placard -" No cont. ops. above 24" btwn. 2350 and 2550 rpm" (M20E & M20F only) Applicable Models: M20A-G M20J Specifications: 74 inch diameter 2-bladed aluminum hub scimitar propeller 2400 hour / 6 year TBO 62-64 pounds (propeller and spinner) Diameter reduction allowable to 72.5 inches Placard -" No cont. ops. above 24" btwn. 2350 and 2550 rpm" (M20E & M20F only) Replaces: Hartzell HC-C2YK-1BF/F7666A-2 or 3Q - 74" or 73" dia 2-bladed propeller models Diameter reduction allowable to 72.5 inches or no diameter reduction allowed on q-tip 2000 hour / 5 year TBO 57 or 59 pounds (propeller and spinner) Placard - "Avoid cont. ops. between 2100 and 2350 rpm." Repetitive eddy current inspection per AD2006-18-15 Hartzell HC-C3YR-1RF/F7282 - 74" dia. 3-bladed prop Diameter reduction allowable to 73 inches 2400 hour / 6 year TBO 71 pounds (propeller and spinner) Placard - "Avoid cont. ops. Below 15" btwn. 1950 and 2350 rpm". McCauley C53, C212 or C214 - 74" dia. 2-bladed prop Diameter reduction allowable to 72.5 or 73 inches 1200-1500 hour / 5 year or 2000 hour / 6 year TBO 52.3 pounds or 54.3 pounds (propeller and spinner) Placard - "Avoid cont. ops. below 15" btwn 1500 and 1950 rpm." (C212 & C214) Advantages: Reduced noise Same or better climb performance Improved cruise performance efficiency Longer TBO Current, attractive design Notes: Not eligible on fixed pitch M20D Slightly longer take-off roll (3% over 7666-2 blade) Quote
Shadrach Posted October 3, 2013 Report Posted October 3, 2013 I get it. so the Schimitar conversion moves the "avoid continous" range from 2150-2350RPM to 2350-2550RPM. Interesting! Quote
Bob_Belville Posted October 3, 2013 Report Posted October 3, 2013 I get it. so the Schimitar conversion moves the "avoid continous" range from 2150-2350RPM to 2350-2550RPM. Interesting! Right. New and different placard required. Quote
garysuperpilot Posted October 3, 2013 Report Posted October 3, 2013 Now I'm confused. My scimitar prop says no operation between 2350 and 2550 unless manifold pressure is 24" or below. I didn't think it changed the engine operating limitation between 2150 and 2350?? Haven't had my 67 f model long but did have the paperwork and it listed the mp limitation. I called hartzell about it and that's what I was told. Somebody help. I don't think the original limitation was eliminated by the new prop, just an additional limitation. Quote
Shadrach Posted October 3, 2013 Report Posted October 3, 2013 Now I'm confused. My scimitar prop says no operation between 2350 and 2550 unless manifold pressure is 24" or below. I didn't think it changed the engine operating limitation between 2150 and 2350?? Haven't had my 67 f model long but did have the paperwork and it listed the mp limitation. I called hartzell about it and that's what I was told. Somebody help. I don't think the original limitation was eliminated by the new prop, just an additional limitation. Placard -" No cont. ops. above 24" btwn. 2350 and 2550 rpm" (M20E & M20F only) Replaces: Hartzell HC-C2YK-1BF/F7666A-2 or 3Q - 74" or 73" dia 2-bladed propeller models Diameter reduction allowable to 72.5 inches or no diameter reduction allowed on q-tip 2000 hour / 5 year TBO 57 or 59 pounds (propeller and spinner) Placard - "Avoid cont. ops. between 2100 and 2350 rpm." Repetitive eddy current inspection per AD2006-18-15 Yes but Bob's paperwork clearly states that the old placard is replaced by the new one... Quote
Bob_Belville Posted October 3, 2013 Report Posted October 3, 2013 Placard -" No cont. ops. above 24" btwn. 2350 and 2550 rpm" (M20E & M20F only) Replaces: Hartzell HC-C2YK-1BF/F7666A-2 or 3Q - 74" or 73" dia 2-bladed propeller models Diameter reduction allowable to 72.5 inches or no diameter reduction allowed on q-tip 2000 hour / 5 year TBO 57 or 59 pounds (propeller and spinner) Placard - "Avoid cont. ops. between 2100 and 2350 rpm." Repetitive eddy current inspection per AD2006-18-15 Yes but Bob's paperwork clearly states that the old placard is replaced by the new one... That is correct. Only the 24"+/2350-2550 restriction applies when you switch to the Scimitar. That is really not hard to avoid unless someone is an old timer climb at 25 square. I use 2550 all the time, the engine seems to purr there. Quote
garysuperpilot Posted October 3, 2013 Report Posted October 3, 2013 Maybe I don't have to worry about the previous limitation either. I'm going to recheck what my paperwork says. Quote
garysuperpilot Posted October 8, 2013 Report Posted October 8, 2013 Called Hartzell about the prop and was told the original limitation of 2100 - 2350 is eliminated with the schmitar prop. One less thing to think about. My Cherokee never had these kind of considerations.... but it was 40knots slower burning the same amount of fuel. I'll keep the Mooney thank you. Quote
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