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#1
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Yea -- my point was that this is ALMOST a good idea. But not quite.
Lotsa those! Much better to just use a normal V6 or V8 and a PSRU. Many such that have gone 2000+ hours. As for weight and CG, I'd use the V6 STOL as an example. This is a set of plans done in the '60's by a guy named Blanton. It has you buy a trashed Piper tri-pacer and use the parts to build a new aircraft. More HP, longer wings, and a lengthened fuselage made for a really good aircraft. There were about 500 built, and there is only 1 on the NTSB crash database. He actually had FAA approval at one time. For the engine, he used a 3.8 Liter Ford V6. They are still selling derivatives today. After he hot-rodded it, he got 260 HP out of the engine, but derated it to 230 HP. According to the Blanton plans, it weighed 14 pounds more than a comparably equipped IO360 Lyc (180 HP). Point is that the V6 engine with belt PSRU meant he could use an engine big enough to do the job in style. And since it is water cooled, you can run it at the stoicheometric (sp?) point of 14.7:1 air fuel mixture, instead of the 10:1 or so necessary in an air cooled engine to keep the valves from burning. That leaner mixture translates to considerably better gas mileage (up to 30% better). What that improvement translates to is that you need carry less fuel. So even though the engine is 14 pounds heavier, 30% less fuel means overall you are carrying less weight. And 50 more HP. "cavelamb himself" wrote in message ... Ron Webb wrote: "Certain types of V engine have been built as inverted engines, most commonly for aircraft. Advantages include better visibility in a single-engined airplane, and lower centre of gravity." An aluminum V8 was adapted in the 1960s to power ---I want to say the Whittman Tailwind, but I could be wrong --- it was run direct drive and inverted. Ran fine for many years. One problem was that the oiling system had to be redesigned. It was originally designed to pump oil up into the valve covers, then let it drain back down. Obviously that won't work if the whole engine is upside down. Also the carb had to be replaced (float bowls don't work upside down either.) Neither change is trivial, both are do-able. As I recall, Wittman said big problem was that the engine ate plugs in the inverted position. Barely get 20 hours on a set... You can see why it would result in a lower center of gravity - the crank (directly connected to the prop) becomes the highest point on the engine instead of the lowest. Same for visibility - the whole engine is lower and out of the way. But that all assumes you are going to use it direct drive - which almost nobody does. If you use a gearbox, belt PSRU, or HiVo chain PSRU, they will all give you an offset of several inches, making for the same center of gravity without the other changes, and allowing for much greater power, because engine RPM's can be run much higher for the same prop RPM. And what does all that do to 1) weight and 2) CG ??? |
#2
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Ron Webb wrote:
Yea -- my point was that this is ALMOST a good idea. But not quite. Lotsa those! Much better to just use a normal V6 or V8 and a PSRU. Many such that have gone 2000+ hours. As for weight and CG, I'd use the V6 STOL as an example. This is a set of plans done in the '60's by a guy named Blanton. It has you buy a trashed Piper tri-pacer and use the parts to build a new aircraft. More HP, longer wings, and a lengthened fuselage made for a really good aircraft. There were about 500 built, and there is only 1 on the NTSB crash database. He actually had FAA approval at one time. For the engine, he used a 3.8 Liter Ford V6. They are still selling derivatives today. After he hot-rodded it, he got 260 HP out of the engine, but derated it to 230 HP. According to the Blanton plans, it weighed 14 pounds more than a comparably equipped IO360 Lyc (180 HP). Point is that the V6 engine with belt PSRU meant he could use an engine big enough to do the job in style. And since it is water cooled, you can run it at the stoicheometric (sp?) point of 14.7:1 air fuel mixture, instead of the 10:1 or so necessary in an air cooled engine to keep the valves from burning. That leaner mixture translates to considerably better gas mileage (up to 30% better). What that improvement translates to is that you need carry less fuel. So even though the engine is 14 pounds heavier, 30% less fuel means overall you are carrying less weight. And 50 more HP. Ron, how about share with us where you got you information? |
#3
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Ron, how about share with us where you got you information?
I got the information from the set of very old V6 STOL plans I bought a few years ago off of EBay. Paid $75. That's WAYYY out of character for me! It was worth it though. Among other things, there is a blueprint that shows how to convert a PA-22 to a taildragger without the mods to the undercarriage. Just mod the gear to sweep forward. My PA-20 was converted like that, so having the drawing is a good thing. There are perhaps 75 pages of drawings, and 75 pages of text. Covers fuselage mods, wing mods, and converting the engine. I'd share the info if I could get permission from his heirs... |
#4
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Ron Webb wrote:
Ron, how about share with us where you got you information? I got the information from the set of very old V6 STOL plans I bought a few years ago off of EBay. Paid $75. That's WAYYY out of character for me! It was worth it though. Among other things, there is a blueprint that shows how to convert a PA-22 to a taildragger without the mods to the undercarriage. Just mod the gear to sweep forward. My PA-20 was converted like that, so having the drawing is a good thing. There are perhaps 75 pages of drawings, and 75 pages of text. Covers fuselage mods, wing mods, and converting the engine. I'd share the info if I could get permission from his heirs... That's about what I expected. Here, update thyself... http://www.contactmagazine.com/ |
#5
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Thanks for the link. It had been a while since I had looked at the Contact!
web site. The Belted Air Power belt drive is very similar to the Blanton drive. I'm sure I'd rather buy it than build it. I'd heard they weren't selling the BAP unit anymore. Anybody know? I like the info in the old plans because it is one of the few cases I've seen where a certificated engine was removed from a certificated aircraft, then a properly converted auto engine was installed in it's place - with everything on both sides weighed, and pictures of the scale. I've not seen much with better first hand knowledge of weights. And nothing much has changed. I have made a collection of similar info, from every source I can find, including a few of my own weights and measures. I still have the file somewhere...I think. As for the fuel burn info - that is not even in doubt! You can't run an air cooled engine at the Stoicheometric point. Anybody with a pilot's license will tell you that you run rich of peak, or get used to paying for valve jobs among other things. Not so with a water cooled engine. Keeping the mixture EXACTLY at stoich is the whole purpose of an Electronic Fuel Injection system. I DO know something about that. An engine running at Stoich 14.7:1 fuel air mixture WILL get better mileage than one getting the same power at 10:1 mixture. How could it be otherwise? "cavelamb himself" wrote in message ... Ron Webb wrote: Ron, how about share with us where you got you information? I got the information from the set of very old V6 STOL plans I bought a few years ago off of EBay. Paid $75. That's WAYYY out of character for me! It was worth it though. Among other things, there is a blueprint that shows how to convert a PA-22 to a taildragger without the mods to the undercarriage. Just mod the gear to sweep forward. My PA-20 was converted like that, so having the drawing is a good thing. There are perhaps 75 pages of drawings, and 75 pages of text. Covers fuselage mods, wing mods, and converting the engine. I'd share the info if I could get permission from his heirs... That's about what I expected. Here, update thyself... http://www.contactmagazine.com/ |
#6
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On Thu, 20 Dec 2007 17:30:03 -0900, "Ron Webb"
wrote: Thanks for the link. It had been a while since I had looked at the Contact! web site. The Belted Air Power belt drive is very similar to the Blanton drive. I'm sure I'd rather buy it than build it. I'd heard they weren't selling the BAP unit anymore. Anybody know? I like the info in the old plans because it is one of the few cases I've seen where a certificated engine was removed from a certificated aircraft, then a properly converted auto engine was installed in it's place - with everything on both sides weighed, and pictures of the scale. I've not seen much with better first hand knowledge of weights. And nothing much has changed. I have made a collection of similar info, from every source I can find, including a few of my own weights and measures. I still have the file somewhere...I think. As for the fuel burn info - that is not even in doubt! You can't run an air cooled engine at the Stoicheometric point. Anybody with a pilot's license will tell you that you run rich of peak, or get used to paying for valve jobs among other things. Not so with a water cooled engine. Keeping the mixture EXACTLY at stoich is the whole purpose of an Electronic Fuel Injection system. I DO know something about that. An engine running at Stoich 14.7:1 fuel air mixture WILL get better mileage than one getting the same power at 10:1 mixture. How could it be otherwise? Never heard of "agressive leaning" of air cooled aircraft engines? Below peak power it is very viable -- Posted via a free Usenet account from http://www.teranews.com |
#7
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On Thu, 20 Dec 2007 11:21:23 -0900, "Ron Webb" wrote:
As for weight and CG, I'd use the V6 STOL as an example....There were about 500 built, and there is only 1 on the NTSB crash database. He actually had FAA approval at one time. 500 built? I'm skeptical. I did a search of the FAA database using "V-6," "STOL,", "Defunky", "Javelin" and "Blanton" as terms (with the typical variations of "V-6". When you eliminate all the Zenairs and "R V-6"es, I maybe 35 hits. Five hundred flying aircraft is about the same as Fly Babies, and I don't think the Blantons are as common. Blanton was a controversial figure, back then, and there were those who were skeptical of his veracity, and, at times, his sanity. Scroll about halfway down here... http://www.seqair.com/Other/Sawdust/Sawdust1992.html Look for the section starting, "With a tongue like this, who needs a propeller?" Or try... http://bd-4.org/newsletter17.html ....and scroll down to the "Horsepower" section. Ron Wanttaja |
#8
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On Dec 20, 9:19 pm, Ron Wanttaja wrote:
500 built? I'm skeptical. I did a search of the FAA database using "V-6," "STOL,", "Defunky", "Javelin" and "Blanton" as terms (with the typical variations of "V-6". When you eliminate all the Zenairs and "R V-6"es, I maybe 35 hits. Five hundred flying aircraft is about the same as Fly Babies, and I don't think the Blantons are as common. Like most homebuilt projects, there are likely a lot of Blanton conversions sitting in garages and basements all over the world, waiting for the owner to get motivated enough to finish the project. Dan |
#9
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500 built? I'm skeptical. I did a search of the FAA database using
"V-6," "STOL,", "Defunky", "Javelin" and "Blanton" as terms (with the typical variations of "V-6". When you eliminate all the Zenairs and "R V-6"es, I maybe 35 hits. Five hundred flying aircraft is about the same as Fly Babies, and I don't think the Blantons are as common. I'll admit that I don't have any source but Blantons writings for that one. Could be wrong. This far in the future, and 35 IDENTIFIABLE still flying isn't doing that bad. I know of several here in Alaska that have never been registered. Blanton was a controversial figure, back then, and there were those who were skeptical of his veracity, and, at times, his sanity. Scroll about halfway down here... Yea, his name here on RAH was nearly as bad as Zooom's after one fellow (who was that?) got done with him. Blanton's claim that you could get 230 reliable HP out of it was vigorously debated. With open intake, open exhaust, ported heads, big cam and carb, and forged rods and pistons for reliability my desktop Dynamometer program shows over 330 HP at 6500 RPM, and 278 HP at a more sedate 5000 RPM possible, without forced induction. Dyno2000 is usually very close to right. Blanton claimed 260 HP, derated to 230 HP. The commercial version of the Ford 3.8 L with the Northwest Aero belt PSRU attached that shipped with the Adventurer amphib put out around 200, but it was not modified as described above. The ported heads alone would be worth the extra 30 HP. |
#10
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On Fri, 21 Dec 2007 17:45:28 -0900, "Ron Webb"
wrote: Blanton's claim that you could get 230 reliable HP out of it was vigorously debated. With open intake, open exhaust, ported heads, big cam and carb, and forged rods and pistons for reliability my desktop Dynamometer program shows over 330 HP at 6500 RPM, and 278 HP at a more sedate 5000 RPM possible, without forced induction. Dyno2000 is usually very close to right. Blanton claimed 260 HP, derated to 230 HP. I doubt that anyone will argue with that statement. The problem isn't in getting that power out, it is with getting the heat out, even with water cooled engines. An engine, to give 2000 hours MTBF (well, with a 2000 hour TBO, you would want the MTBF significnatly longer) needs more than great tuning. You did say reliable; remember that an airplane engine typically will be expected to operate at 75% to 85% power for hours at a time; an automobile engine in a 2500 lb car (think Cessna 182 or Cirrus) running at 60 MPH probably averages 20 HP. I cannot prove my automobile numbers, and they may be all wet. Look at highly tuned auto engiens ... NASCAR probably gets 800 HP from 350 cu-in ... and they last 4 or 5 hours. Drag racers likely get over double that, but their engines last minutes. Contrary to what many think, most accept that the "obsolete" Lyconental engines are pretty good products, making below 0.4 lb/hp-hr SFC ... better than many cars. That's EFFICIENT! I'd bet that if an auto engine would out perform Lycontental, we'd see them certified and in use; the only water cooled engine I know of in certified applications is the water cooled HEAD engine by Rotax. They get 80 HP @ 5500 rpm from 74 cu-in ... and a 1500 hr TBO. They are not cheap to build, either; even the uncertified ones are in the $15,000 range. Business wants to make money; if you can build a 230 HP engine that will reliably give 2000 hours in an airplane and sell it for $10,000, I'd bet that getting it certified and insured will be a piece of cake .... certified, it is probalby over a $30,000 sale. But my own opinion ... if it were that easy, it would have been done. |
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