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#1
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From memory, the differences were slight. The wing airfoil was different.
The W-10 has a curve on the bottom where the W-8 was flat. I understand that there were 2 or 3 inches of extra width in the fuselage. Also, the W-10 was stressed for larger (Lycoming) engines. I built the airframe for a W-10 and talked with Mr. Wittman about it a couple of times. I also saw him at Oshkosh several times and talked with him in person once. He was a VERY thin man and medium height. I can easily understand the change in the fuselage. He did not think much of people who put in Lycoming 0-290's or 0-320's (like I was going to do). He much preferred the 85hp Continental. When I talked to him, I found out that he was turning his little engine at about 3,200 rpm -- way, WAY over readline. It was putting out as much HP as the larger (and heavier) Lycomings. He did say that he had to overhaul it about every 400 hours. Since he did it himself (rather than hiring an A&E), he did not think that it was a problem at all. "Daniel Lapointe" wrote in message ... Can somebody tell me where to find the difference between a W-8 and a W-10 ? |
#2
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W-10 fuselage is a little bit longer and has a bit more room in the
cockpit area (especially if built as a "C" model - ala Jim Clement). The -10 will carry a larger motor (if you really want), very effective wing tips added, reshaped fin and rudder, and slightly larger stab/elevator. Daniel Lapointe wrote: Can somebody tell me where to find the difference between a W-8 and a W-10 ? Dan |
#3
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Can somebody tell me where to find the difference between a W-8 and a W-10 ?
Start here? http://www.chlassociates.com/Aviation/tailwind.htm |
#4
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Richard Lamb wrote:
Anybody remember a Turner T-40 named "Ophelia Bumps"? +++++++++++++++++++++++++++++++++++++++++ Nope, but Turner's Book... "Fabulous Affairs with Aircraft and Federal Aviation Airheads" $19.95 ea. May still be available through... Turner Aircraft and CAVU Books P.O. Box 74 Cleburne, TX 76033-0074 FWIW... The first "Ophelia Bumps" appears to be a WWII B-24 of the 454th BOb Group. Barnyard BOb -- |
#5
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On Tue, 29 Jul 2003 02:40:10 -0500, Barnyard BOb --
wrote: Richard Lamb wrote: Anybody remember a Turner T-40 named "Ophelia Bumps"? +++++++++++++++++++++++++++++++++++++++++ Nope, but Turner's Book... "Fabulous Affairs with Aircraft and Federal Aviation Airheads" $19.95 ea. May still be available through... Turner Aircraft and CAVU Books P.O. Box 74 Cleburne, TX 76033-0074 FWIW... The first "Ophelia Bumps" appears to be a WWII B-24 of the 454th BOmb Group. Barnyard BOb -- |
#6
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I only met Steve Wittman once, when he had brought his inverted V8 tailwind
to Sun-n-Fun, and didn't talk that long; and then only about the V8. I was not aware that he turned his C85 at 3200 RPM, although it makes good sense given his orientation. Steve was reputed to have long advocated that homebuilt aircraft with small certified engines like the C85 cruise at 85%. The rationale was that most homebuilt aircraft are operated less than 80 hours per year and that rust is the true enemy, rather than wear; so that a conservatively operated engine will never reach its certified TBO. Thus, since most homebuilt aircraft also operate at lower altitudes where higher cruising power can be attained, the hypothesis suggests that it is really more conservative to operate the lighter and less expensive engine at the higher power setting. I do not entirely agree with the concept, mainly because it does not give a lot of extra thrust for takeoff and initial climb on a really slick and fast modern aircraft with a fixed pitch propeller. However, I must admit that it makes a lot of sense for most designs from the 50's 60's and 70's. Peter Harry O wrote: From memory, the differences were slight. The wing airfoil was different. The W-10 has a curve on the bottom where the W-8 was flat. I understand that there were 2 or 3 inches of extra width in the fuselage. Also, the W-10 was stressed for larger (Lycoming) engines. I built the airframe for a W-10 and talked with Mr. Wittman about it a couple of times. I also saw him at Oshkosh several times and talked with him in person once. He was a VERY thin man and medium height. I can easily understand the change in the fuselage. He did not think much of people who put in Lycoming 0-290's or 0-320's (like I was going to do). He much preferred the 85hp Continental. When I talked to him, I found out that he was turning his little engine at about 3,200 rpm -- way, WAY over readline. It was putting out as much HP as the larger (and heavier) Lycomings. He did say that he had to overhaul it about every 400 hours. Since he did it himself (rather than hiring an A&E), he did not think that it was a problem at all. "Daniel Lapointe" wrote in message ... Can somebody tell me where to find the difference between a W-8 and a W-10 ? |
#7
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It seems that I did not think the implications all the way through before I
pressed the "send" button. Running the C85 at 3200 RPM should result in around 125% power, so that a cruise setting of 85% power would be around 65% of the "available" power. Therefore, a clean little airplane like the Tailwind would actually have a greater (rather than less) surplus thrust for take off and initial climb. The note of caution would be that full throttle would be take off only, and not maximum continuous; so the pilot would have to understand the limitations and treat it like a high performance engine rather than like a trainer engine. Peter Peter Dohm wrote: I only met Steve Wittman once, when he had brought his inverted V8 tailwind to Sun-n-Fun, and didn't talk that long; and then only about the V8. I was not aware that he turned his C85 at 3200 RPM, although it makes good sense given his orientation. Steve was reputed to have long advocated that homebuilt aircraft with small certified engines like the C85 cruise at 85%. The rationale was that most homebuilt aircraft are operated less than 80 hours per year and that rust is the true enemy, rather than wear; so that a conservatively operated engine will never reach its certified TBO. Thus, since most homebuilt aircraft also operate at lower altitudes where higher cruising power can be attained, the hypothesis suggests that it is really more conservative to operate the lighter and less expensive engine at the higher power setting. I do not entirely agree with the concept, mainly because it does not give a lot of extra thrust for takeoff and initial climb on a really slick and fast modern aircraft with a fixed pitch propeller. However, I must admit that it makes a lot of sense for most designs from the 50's 60's and 70's. Peter Harry O wrote: From memory, the differences were slight. The wing airfoil was different. The W-10 has a curve on the bottom where the W-8 was flat. I understand that there were 2 or 3 inches of extra width in the fuselage. Also, the W-10 was stressed for larger (Lycoming) engines. I built the airframe for a W-10 and talked with Mr. Wittman about it a couple of times. I also saw him at Oshkosh several times and talked with him in person once. He was a VERY thin man and medium height. I can easily understand the change in the fuselage. He did not think much of people who put in Lycoming 0-290's or 0-320's (like I was going to do). He much preferred the 85hp Continental. When I talked to him, I found out that he was turning his little engine at about 3,200 rpm -- way, WAY over readline. It was putting out as much HP as the larger (and heavier) Lycomings. He did say that he had to overhaul it about every 400 hours. Since he did it himself (rather than hiring an A&E), he did not think that it was a problem at all. "Daniel Lapointe" wrote in message ... Can somebody tell me where to find the difference between a W-8 and a W-10 ? |
#8
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![]() "Peter Dohm" wrote in message ... It seems that I did not think the implications all the way through before I pressed the "send" button. Running the C85 at 3200 RPM should result in around 125% power, so that a cruise setting of 85% power would be around 65% of the "available" power. Therefore, a clean little airplane like the Tailwind would actually have a greater (rather than less) surplus thrust for take off and initial climb. The note of caution would be that full throttle would be take off only, and not maximum continuous; so the pilot would have to understand the limitations and treat it like a high performance engine rather than like a trainer engine. Peter Most of the faster homebuilts with fixed pitch props don't generate maximum power at takeoff simply because the props have so much pitch the engine can't spin 'em to peak rpm. The EZ crowd discovered this years ago. If I wanted to spend a couple of hours reading old issues of "Canard Pusher" or whatever the appropriate newsletter was, I could find a cite by the Rutan Aircraft Factory where they recommend a slightly underpitched prop which would allow more than the *certified* max RPM. This was primarily done to allow the engine to generate more RPM and power at takeoff. In my 0-320 RV-6, the engine only turns 2100 rpm on takeoff. As the airplane accelerates, the rpm's increase as does my climb rate. The airplane climbs better at 125 knots than 100, simply because the engine is generating quite a few more horsepower. KB |
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