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Jatro13th
04-12-2006, 08:21 AM
Hi all!

I found out some time ago about a Greek guy who designed and built his own airplane and the engine he used for it came from a Volkswagen beetle. From what I know, the biggest engine for that car, countig off the Porsche ones, is the 1600cc 50 HP one (the one I used to have). So, how did this guy build that plane with only a 50 HP engine?

Is there a difference in the way that we measure HP in an engine according to the purpose for which that engine is used? (land sea water etc).

Here is a photo of it to see its size:

http://users.otenet.gr/~xfl/ag.jpg

Thanks!

FI-Aflak
04-12-2006, 08:49 AM
HP is measured the same way. You don't need a 2000HP engine to make an airplane fly - all it needs to do is overcome drag forces at a great enough speed for the plane to be flying (that, and get to a high enough speed in the length of a runway).

I think that a 50HP motor would be more than enough for a small private aircraft.

-HH-Dubbo
04-12-2006, 09:00 AM
Both VW & Subaru are popular for homebuilts due to their boxer layouts. (VW because it was air-cooled too) BTW VW air-cooled boxer engines were available in 1800cc & 2100cc versions as well....my family had many VWs.

Even Rotax engines are quite small and they seem to work. 1200cc & 80hp for example.

Jatro13th
04-12-2006, 10:32 AM
1800 and 2000 cc? Really? Well I didn't know that!

Anyway, yes, I understand that the engine is supposed to overcome drag etc, but I had the impression that a 50 HP only engine would make the a/c rather cumbersome and difficult to fly...

Thanks for replying!

luftluuver
04-12-2006, 11:00 AM
Shortly after Piper assumed control of the company, Taylor Aircraft introduced an improved E-2 airframe, powered by the newly developed Continental Motors Corporation <span class="ev_code_YELLOW">37-horsepower </span> (28-kilowatt) A-4O engine. The new Taylor E-2, now known as the €œCub,€ was awarded its type certificate on July 11, 1931 and licensed by the U.S. Department of Commerce for manufacture. Twenty-two Taylor E-2 Cubs were sold during 1931, retailing for $1,325; by 1935, sales had increased to more than 200 E-2 Cubs.

Lilliputian by today's standards, the two-seat J-3 Cub was only 22 feet 2 inches (6.5 meters) long, stood 80 inches (2 meters) high, and had a wingspan of 35 feet 2 inches (10.7 meters). When powered by the Lycoming <span class="ev_code_YELLOW">65-horsepower </span> (48-kilowatt) engine, the J-3 Cub attained a maximum speed of 85 miles per hour (137 kilometers per hour) with a ceiling of 9,300 feet (283 meters). Even more remarkable, the fuel tank held only 12 gallons (45.4 liters), sufficient to fly about 190 miles (351 kilometers)€"compare this to your modern automobile!

http://www.centennialofflight.gov/essay/GENERAL_AVIATION/piper/GA6.htm

Kocur_
04-12-2006, 12:32 PM
It can go lower http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif
Polish pre-WW2 motoglider B...k - 18 (eighteen) PS http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif
http://www.piotrp.de/SZYBOWCE/pbak1.htm

And I bet it can be even lower.

vocatx
04-12-2006, 12:59 PM
I've read of a home-built aircraft that used an 18 hp Kohler engine (similar to the one in a riding lawn-mower), but this is the smallest piloted aircraft I know of:

http://flight.cz/cricri/english/

StellarRat
04-12-2006, 01:02 PM
Remember there was the HUMAN powered plane that flew across the English Channel. If I remember correctly humans can generate about 1/10 to 1/3 sustained horsepower (depending the physical condition of the person.) So, it doesn't take much. http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

NonWonderDog
04-12-2006, 02:38 PM
The human-powered planes are ultralight class, though -- they don't really count. You can build an ultralight with a lawnmower engine... and you don't even need a pilot's licence to kill yourself in it.

Seriously, though, a lot of pre-1960 commercial GA planes had sub-100hp engines. The C150 came with an 100hp Continental, at least a few people upgraded to the 115hp Lycoming used in the C152. That's takeoff power; cruise is ~65hp. You really don't need much power for a little private plane.

luftluuver
04-12-2006, 03:08 PM
Originally posted by Kocur_:
It can go lower http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif
Polish pre-WW2 motoglider B...k - 18 (eighteen) PS http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif
http://www.piotrp.de/SZYBOWCE/pbak1.htm

And I bet it can be even lower. It wasn't about being the lowest powered that I made the post.

Here is a site to one of the early homebuilts, the Pietenpol using a Model A engine http://www.airventuremuseum.org/collection/aircraft/Pietenpol%20Aircamper.asp

Kocur_
04-12-2006, 03:20 PM
Originally posted by luftluuver:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kocur_:
It can go lower http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif
Polish pre-WW2 motoglider B...k - 18 (eighteen) PS http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif
http://www.piotrp.de/SZYBOWCE/pbak1.htm

And I bet it can be even lower. It wasn't about being the lowest powered that I made the post.

Here is a site to one of the early homebuilts, the Pietenpol using a Model A engine http://www.airventuremuseum.org/collection/aircraft/Pietenpol%20Aircamper.asp </div></BLOCKQUOTE>

Naa, I was referring to original poster's 50hp http://forums.ubi.com/images/smilies/touche.gif http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

|CoB|_Spectre
04-12-2006, 03:21 PM
Hanging automobile engines on airframes is nothing new. Getting them to work optimally and, most of all, reliably has been the problem.

Obviously it needs to be light with as high a power-to-weight ratio as possible. One of the biggest issues has always been that auto and aircraft engines operate very differently. Automobiles rarely run at rated power for any appreciable length of time whereas aircraft engines do it regularly during takeoff and climbout. Peak torque requirements for a car usually arrive at a different rpm than is needed for an aircraft. High-revving engines must use a PSRU (Prop Speed Reduction Unit) to keep propellar tip speeds subsonic. So, there are many things to consider when adapting an automobile engine to an aircraft. Most of all, do you want to strap yourself into an airplane with an unproven engine? Maybe if you're over a huge dry lake bed with plenty of landing options.

luftluuver
04-12-2006, 03:32 PM
Originally posted by Kocur_:
Naa, I was referring to original poster's 50hp http://forums.ubi.com/images/smilies/touche.gif http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif OK http://forums.ubi.com/images/smilies/touche.gif http://forums.ubi.com/images/smilies/25.gif

GreyFox5
04-12-2006, 04:15 PM
Been flying in this 1946 Aeronca Champ with a Continental A65 65hp with a 13gal tank. Flys for 3.5 hours if you ran the tank dry (Pilot runs only 2.5hrs max) and it crusies about 65-70 mph.
http://img.photobucket.com/albums/v476/GreyFox5/SmallChamp.jpg

Jatro13th
04-13-2006, 06:08 AM
Thanks for the replys guys! It was quite illuminating! Didn't know that there were planes safe enough to be trusted with such a low HP motors!

Cheers!

XyZspineZyX
04-13-2006, 06:26 AM
I saw this (http://www.aircraft-spruce.com/da11.html) on Extreme Machines a long while ago on Discovery Channel. Homebuilt aircraft flying on one 18HP Briggs and Stratton lawn mower engine. It was a hoot to watch it fly.

vocatx
04-13-2006, 09:12 AM
Thanks, Skunk! That's the one I was thinking about, I just couldn't find a link to it.

Sergio_101
04-13-2006, 04:55 PM
Some ultra lights are powered by chainsaw motors!
Power required to fly is a function of weight
and the wing's efficency.

Remember, there have been a number of human powered airplanes.
Humans can not make even one horsepower for long.

Automotive conversions have been used since
the Wrights first flew.

Name a popular automobile engine and I'll bet
it has powered an airplane somewhere!

Flat head Fords, Wankle rotarys, Chevrolet V8s
you name it, they have flown.

There was a company offering a QEC "Big Block Chevy"
unit supposedly airworthy for general avaition.

The primary down side to automotive power is
the generally poor power to weight ratio.
Another major factor is automotive engines
are generally not designed to run at sustained
high power outputs.

Sergio

ImpStarDuece
04-13-2006, 05:07 PM
One of the latest Bugatti supercars has a pair of V-8 engines in the back, each pushing out just over 500hp http://forums.ubi.com/groupee_common/emoticons/icon_eek.gif

When you realise that most military aircraft before 1936 were struggling to mount engines with more than 900hp, it seems a little excessive at times.

ATLAS_DEATH
04-13-2006, 06:40 PM
And there is a difference between fighter planes and private planes... the fighters had to go fast and deal with heavy weight. Little privot planes are small and light.. no need for 4k horses http://forums.ubi.com/groupee_common/emoticons/icon_razz.gif

MM-Zorin
04-13-2006, 08:47 PM
Another good example is the two seater Siebel SI 202 of the late 30s.

It's version A had a 45hp enigne, a range of 470km and a cruising speed of 140km/h.

Version C had 60hp, a range of 800km and a cruising speed of 150km/h.

Z4K
04-14-2006, 08:14 AM
The AR-5 holds a world speed record of 213mph (342km/h) with a 65hp engine.

http://www.ar-5.com/

Sweet little plane.