Comments - Long Cross Country puts Corvair to the Test - Zenith Aircraft Builders and Flyers2024-03-29T09:47:44Zhttps://zenith.aero/profiles/comment/feed?attachedTo=2606393%3ABlogPost%3A494277&xn_auth=noI had a 912 with high comp pi…tag:zenith.aero,2016-03-10:2606393:Comment:4948892016-03-10T04:09:18.262ZBob Hartunianhttps://zenith.aero/profile/BobHartunian
<p>I had a 912 with high comp pistons that probably made ~90 hp and could accept a wooden GSC 2-blade gnd adj prop. But when I changed to a 912S, the old prop could not absorb the higher power, so I installed a 3-blade, 62" Warp Drive and it does take all the power engine can make. One good thing about a wood prop is that it does run smooth by absorbing engine pulses and in case of a prop strike, it destructs and keeps energy from damaging engine.</p>
<p>If you have demonstrated stalls with…</p>
<p>I had a 912 with high comp pistons that probably made ~90 hp and could accept a wooden GSC 2-blade gnd adj prop. But when I changed to a 912S, the old prop could not absorb the higher power, so I installed a 3-blade, 62" Warp Drive and it does take all the power engine can make. One good thing about a wood prop is that it does run smooth by absorbing engine pulses and in case of a prop strike, it destructs and keeps energy from damaging engine.</p>
<p>If you have demonstrated stalls with loaded plane with Corvair engine and no adverse reactions, I'd call that successful.</p>
<p>Up here in mtns, you set prop for climb initially to clear ridges at 8500' and then experiment by adding pitch to make higher cruise speed and try for the best compromise of both. The Warp Drive with tapered tips does good job of climb and cruise.</p> Bob, The Corvair is definit…tag:zenith.aero,2016-03-08:2606393:Comment:4946642016-03-08T21:26:18.631ZJon Reddickhttps://zenith.aero/profile/JonReddick
<p>Bob, The Corvair is definitely heavier than the 912. From what I recall, it is in the 200-220lb range once installed with all it's accessories. My experience has been that flying with a passenger actually puts the CG right in the sweet spot so that very little trim is needed. I don't really notice any difference in the way it recovers from a stall whether I'm by myself or with a passenger. It's virtually impossible to load this thing with an aft CG, for which I'm thankful. The flip…</p>
<p>Bob, The Corvair is definitely heavier than the 912. From what I recall, it is in the 200-220lb range once installed with all it's accessories. My experience has been that flying with a passenger actually puts the CG right in the sweet spot so that very little trim is needed. I don't really notice any difference in the way it recovers from a stall whether I'm by myself or with a passenger. It's virtually impossible to load this thing with an aft CG, for which I'm thankful. The flip side is that another engine manufacturer (so take it with a grain of salt) warned me that it would be way too nose-heavy with one passenger, no baggage and full fuel and would be dangerous in an off-airport landing situation. Having practiced my fair share of simulated engine out landing's solo, I can assure anyone looking at the corvair that it isn't dangerously nose-heavy. I will admit that with the gear facing the "normal" way, it is difficult to hold the nose off very long upon landing. Several folks have experimented with reversing the direction the main gear faces and report a real improvement in that regard. </p>
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<p>As far as the prop, I'm using a ground adjustable warp-drive as specified by William Wynn. I fly at sea level and rarely cruise long distances, so the prop is currently set to favor takeoff/climb performance. I did some climb testing up to about 8,500' this past January and still had a healthy 300-500 fpm of climb left at that altitude.</p> Jon;
Thanks for clarification…tag:zenith.aero,2016-03-08:2606393:Comment:4946222016-03-08T20:43:14.271ZBob Hartunianhttps://zenith.aero/profile/BobHartunian
<p>Jon;</p>
<p>Thanks for clarification.</p>
<p>I assume the Corvair engine is heavier than 912S but not sure of power it develops. Does increased nose weight effect stall characteristics with 2 aboard? I know it can on Pulsar using the Jab 3300.</p>
<p>Are you running a ground adjustable prop? I fly out of 7K' airport (L35) and having an adjustable prop makes for safer climb margins. Most props are designed for lower altitude flying and can cause issues on climb performance at high density…</p>
<p>Jon;</p>
<p>Thanks for clarification.</p>
<p>I assume the Corvair engine is heavier than 912S but not sure of power it develops. Does increased nose weight effect stall characteristics with 2 aboard? I know it can on Pulsar using the Jab 3300.</p>
<p>Are you running a ground adjustable prop? I fly out of 7K' airport (L35) and having an adjustable prop makes for safer climb margins. Most props are designed for lower altitude flying and can cause issues on climb performance at high density altitude airports. We get 10K' DA at least twice/yr here.</p>
<p>Hope you flight testing goes well.</p>
<p>Bob H</p> Jon, I am building basically…tag:zenith.aero,2016-03-08:2606393:Comment:4944162016-03-08T13:30:57.375ZEarnest Fontenothttps://zenith.aero/profile/EarnestFontenot
<p>Jon, I am building basically the same combination that you have, 650-B w/ 3000 cc Corvair. Thanks for the numbers and inspiration! Last weekend I rented a Cherokee for a XC flight. At WOT it did 105-110 kts IAS burning about 8 - 9 gph. Getting the same speed with less burn is what I;m looking for. Some people want more speed - speed - speed, which is fine but, I want more fly - fly - fly!! Thanks again for the report, it shows that my decision to pick this combo is the right one for…</p>
<p>Jon, I am building basically the same combination that you have, 650-B w/ 3000 cc Corvair. Thanks for the numbers and inspiration! Last weekend I rented a Cherokee for a XC flight. At WOT it did 105-110 kts IAS burning about 8 - 9 gph. Getting the same speed with less burn is what I;m looking for. Some people want more speed - speed - speed, which is fine but, I want more fly - fly - fly!! Thanks again for the report, it shows that my decision to pick this combo is the right one for me.</p>
<p>Earnie</p> Bob, the plane will do 130 fl…tag:zenith.aero,2016-03-08:2606393:Comment:4944022016-03-08T03:37:42.757ZJon Reddickhttps://zenith.aero/profile/JonReddick
<p>Bob, the plane will do 130 flat out. I've got 1k rpm climb so there is the possibility of giving up some of that for more cruise, but the vne is 140, so I think the limitation is more the airframe than the engine. </p>
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<p>Joe, farthest trio prior to this one was an hour each way. </p>
<p>Bob, the plane will do 130 flat out. I've got 1k rpm climb so there is the possibility of giving up some of that for more cruise, but the vne is 140, so I think the limitation is more the airframe than the engine. </p>
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<p>Joe, farthest trio prior to this one was an hour each way. </p> HI JON, BEFORE THE LONG X…tag:zenith.aero,2016-03-08:2606393:Comment:4943872016-03-08T01:33:47.258Zjoseph aloofhttps://zenith.aero/profile/joseph
<p>HI JON, BEFORE THE LONG X COUNTRY, WHAT WAS YOUR LONGEST FLIGHT WITH THE 601?? JOE</p>
<p>HI JON, BEFORE THE LONG X COUNTRY, WHAT WAS YOUR LONGEST FLIGHT WITH THE 601?? JOE</p> Looks like you had a great tr…tag:zenith.aero,2016-03-08:2606393:Comment:4943052016-03-08T00:48:21.938ZHarold Bickfordhttps://zenith.aero/profile/HaroldBickford
<p>Looks like you had a great trip. Much more interesting than flying at 35,000 feet. The accomplishment is yours both in building and flying.</p>
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<p>Harold</p>
<p>Looks like you had a great trip. Much more interesting than flying at 35,000 feet. The accomplishment is yours both in building and flying.</p>
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<p>Harold</p> Are the speeds posted, ~115 m…tag:zenith.aero,2016-03-08:2606393:Comment:4945542016-03-08T00:18:36.648ZBob Hartunianhttps://zenith.aero/profile/BobHartunian
<p>Are the speeds posted, ~115 mph, typical for the 601? I would have expected higher IAS with the bigger engine.</p>
<p>Was the prop adjusted for climb rather than cruise? As a comparison, I fly a Pulsar XP with a 912S and cruise at 140 mph burning 4 1/2 gph with a Warp Drive 3-blade prop. The 701 I'm building now would be a major speed contrast but it's intended for visiting rough landing places in Calif desert and not Xcntry.</p>
<p>Are the speeds posted, ~115 mph, typical for the 601? I would have expected higher IAS with the bigger engine.</p>
<p>Was the prop adjusted for climb rather than cruise? As a comparison, I fly a Pulsar XP with a 912S and cruise at 140 mph burning 4 1/2 gph with a Warp Drive 3-blade prop. The 701 I'm building now would be a major speed contrast but it's intended for visiting rough landing places in Calif desert and not Xcntry.</p> Congratulations Jon, Mr. Pilo…tag:zenith.aero,2016-03-08:2606393:Comment:4944692016-03-08T00:03:46.181ZRon Lendonhttps://zenith.aero/profile/RonLendon
Congratulations Jon, Mr. Pilot. I'm planning a long one too. I'll report at the end.
Congratulations Jon, Mr. Pilot. I'm planning a long one too. I'll report at the end. Nothing like a good tail wind…tag:zenith.aero,2016-03-07:2606393:Comment:4943012016-03-07T23:55:20.981ZThomas Jacksonhttps://zenith.aero/profile/THOMASJACKSON
<p>Nothing like a good tail wind in life! Sounds like you had a good flight, but watch for those head winds.</p>
<p>Thanks for the documentary.</p>
<p>Nothing like a good tail wind in life! Sounds like you had a good flight, but watch for those head winds.</p>
<p>Thanks for the documentary.</p>