Vfr 750 As An Aircraft Engine?

This is my first post and I've got a bit of a strange question. I want to put a Honda 750 VFR engine into a CH701 experimental kit plane. The plane requires an engine from 50-100 horsepower. The plane takes off in as little as 90 feet with one person aboard. (it's a two seater) One fellow already put a Harley Davidson motor in his CH701 and the performance was awesome except the vibration was so bad that he could read any of the flight instruments. My friend sold me two Honda 750 VFR engines for $50 each and they look to be in great shape. I want to remove the transmission gears and clutch system in order to reduce the overall weight. I believe that the dry engine weight is 170lbs. My all up engine maximum for the aircraft is 200lbs. I've heard that the Honda VFR engines had almost no vibration, 100hp and 58 ft-lbs of torque. If I can lower the overall weight by about 30lbs then the all up wet weight will meet the 200lb max engine weight for the aircraft. Does anyone have any thoughts on this? Am I completely off my rocker or do you think that this idea will work? Here are a few links to what I am talking about. http://www.ch701.com/ http://homebuilthelp...BuildVideos.htm

Iwerk, on May 14 2009, 02:46 PM, said: This is my first post and I've got a bit of a strange question. I want to put a Honda 750 VFR engine into a CH701 experimental kit plane. The plane requires an engine from 50-100 horsepower. The plane takes off in as little as 90 feet with one person aboard. (it's a two seater) One fellow already put a Harley Davidson motor in his CH701 and the performance was awesome except the vibration was so bad that he could read any of the flight instruments. My friend sold me two Honda 750 VFR engines for $50 each and they look to be in great shape. I want to remove the transmission gears and clutch system in order to reduce the overall weight. I believe that the dry engine weight is 170lbs. My all up engine maximum for the aircraft is 200lbs. I've heard that the Honda VFR engines had almost no vibration, 100hp and 58 ft-lbs of torque. If I can lower the overall weight by about 30lbs then the all up wet weight will meet the 200lb max engine weight for the aircraft. Does anyone have any thoughts on this? Am I completely off my rocker or do you think that this idea will work? Here are a few links to what I am talking about. http://www.ch701.com/ http://homebuilthelp...BuildVideos.htm Uhmmmmm.. you might consider putting in some sort of redundant electrical charging system, backed up with monitoring (voltmeters). The known RR problems sith the engine does result in some failures that happens "out of the blue" on the road. Beck 95 VFR

I've seen videos of the HD motored plane so I know Iwerk isn't completely off his rocker. :+1:

As Beck pointed out, the VFR can have charging issues but otherwise is a very reliable powerplant and should be worthy of your consideration. It would sound awesome too. Personally, I'd look at the tons of available Japanese air-cooled inline fours. Suzuki's performance oil-cooled GSXR units are very reliable plus they also utilize a more automotive type of charging system. Finding a good one for $50 would probably be fantasy though. FWIW

Your hp/torque numbers will depend on what type of 750 engine you purchased: Honda VFR750
The Honda designed V4 configuration does reduce vibration but driving one daily I would not say they are as smooth as say in in-line 4 (sorry BLS).

Truth be told you could get a 600cc sport bike engine that would be lighter and more powerful to meet your weight/performance requirements. The VFR's were never really good at losing weight. http://www.vfrdiscus...tyle_emoticons/default/wink.gif

Edit: Fotomoto beat me to the punch. :+1:

short take-off huh. Is this your first LSA?

Yeah, I would go with a 600cc inline engine instead as well. Smaller and lighter. Plus, the 912s is probably air cooled. Oh, and the max suggested engine weight is 185.

I think the idea of a snarling 750 would be awesome!

Looking on Zenith's site, the Rotax 912 engines put out power about like a car engine.. topping out under 6000 rpm, and that would be about the same for the HD engine. These (and most bike engines) barely start to wake up at that point... So is 10k to 12k RPMs suitable for this application? You mentioned about saving weight... leaving the transmission intact would give you some gearing choices to get the output shaft speed down without some other transmission.

Also... (and I could be wrong... if someone can verify) but I think the oil pump (on the 800 engines anyway) is driven off of one of the transmission shafts... Yeah and the cooling system. You would end up with a more complex setup, but it would also be pretty cooooooooooooool http://www.vfrdiscus...tyle_emoticons/default/smile.gif

I'm not trying to rain on your idea... just pointing out stuff that stands out to me. I think (agree) if you could setup redundant charging systems and if you could rubber mount the sucker (they are rigid in the bikes, but don't know what harmonic vibrations would do in a frame the size of a plane) and deal with the gearing it would be quite unique http://www.vfrdiscus...tyle_emoticons/default/smile.gif

The aircraft-specific engines, do they have fail-over electrical systems? I've seen a couple 6 cylinder Lycoming engines apart, but couldn't really tell about the electrics.

I'd try to find something air cooled to reduce complexity and one less system that could fail in-flight. What about carb icing? You probably want something that revs lower unless there's a prop out there that works over a very wide range of engine speeds.

Anyone want to give this guy a Suzi GS1100E to hack up instead? Old school muscle inline-4 without radiators seems like the way to go here. Still a rever compared to a Rotax 912. ST1100 might be a good donor but back to water cooling.

There seems to be no end to the ingenuity the LSA aircraft guys use to power their kites. I wish I could be more helpful but I only get glances at these things, I engineer avionics on a jet, so not that useful either.

Sounds to me like vibration is a concern of yours... I know it is for me.

The reason the guy put the HD motor in his aircraft is simple... it is air cooled. But it is also a 45 degree twin that is horribly unbalanced, antiquated, leaks and is underpowered.

I would look into 90 degree Ducati dual spark air cooled twins... like the engines that power the Monster 1100 or hypermotard. These are far more modern than the majority of HD motors, produce much more horsepower and are inherently balanced in the primary because of the 90 degree L-twin configuration. Reliablity might come into question... as with leaking as air cooled motors are subject to greater temperature ranges. But overall these engines have a very good reputation and I bet they are also lighter than the HD lug.

As mentioned before any of the air/oil cooled inlines by the japs would be good to, but they do vibrate a good deal.

I would stay away from liquid cooled engines in this application.

[image: View Post]vanion2, on May 14 2009, 07:21 AM, said:

The Honda designed V4 configuration does reduce vibration but driving one daily I would not say they are as smooth as say in in-line 4 (sorry BLS).
Only I4s with power robbing balancers are as smooth as V4s... take away the balancers and it's back to the buzz...

I'd stick with the Rotax 912 that the plane was designed around. Motorcycle engines are designed to produce high power abruptly for short periods of time. Aircraft engines are design for continuous power for hours on end. Motorcycle engines are simply designed for a different application. It might be cheaper on the front end, but it will destroy your resale value for the aircraft. Nobody wants to buy a plane with a highly modified engine. Most likely are some point you will want to trade up and finance it with the sale of your current aircraft.

By the way, I am just starting to build a Cozy MKIV. Enjoy your build.

The ST 1300 V4 would make a better aircraft engine... more torque at lower RPMS... plus there is a
possibilty to use existing shaft in the engine as a start for gear reduction and propeller mount...

[image: Posted Image]

[image: View Post]BusyLittleShop, on May 14 2009, 11:27 AM, said:

The ST 1300 V4 would make a better aircraft engine... more torque at lower RPMS... plus there is a
possibilty to use existing shaft in the engine as a start for gear reduce and propeller mount...

http://www.mcnews.co...Engine_200p.JPG
Never seen an ST1300 engine out like that, pretty little mill. Would look quite nice under the hood of my Ford Capri!

[image: View Post]afennell, on May 14 2009, 09:24 AM, said:

Motorcycle engines are designed to produce high power abruptly for short periods of time.
Negative... Motorcycle engines are engineered to produce high power for long periods of time... not
short... magazines have run a number of motorcycles at full throttle 12,000 rpms for 24 hours in the
quest of a record... trying running an aircraft engine at 12,000 RPMs and see what happens...

[image: View Post]pres589, on May 14 2009, 09:34 AM, said:

http://www.mcnews.co...Engine_200p.JPG

Never seen an ST1300 engine out like that, pretty little mill. Would look quite nice under the hood of my Ford Capri!
Forget cars... I was thinking of bolts 2 1300 together and producing a 2600 V8 to power my
Chipmunk... sort of a 240HP mini Merlin...

[image: View Post]BusyLittleShop, on May 14 2009, 12:36 PM, said:

[image: View Post]afennell, on May 14 2009, 09:24 AM, said:

Motorcycle engines are designed to produce high power abruptly for short periods of time.
Negative... Motorcycle engines are engineered to produce high power for long periods of time... not
short... magazines have run a number of motorcycles at full throttle 12,000 rpms for 24 hours in the
quest of a record... trying running an aircraft engine at 12,000 RPMs and see what happens...

Yeah, but will a motorcycle engine run above 75% throttle continuously and achieve 2000 hours of time between overhauls. Would you bet your life on it?

[image: View Post]ihilker, on May 14 2009, 10:16 AM, said:

The reason the guy put the HD motor in his aircraft is simple... it is air cooled. But it is also a 45 degree twin that is horribly unbalanced, antiquated, leaks and is underpowered.
Not really. Most unmodified HD engines run fine and don't leak anymore than anything else. Part of the reason for its use may have been that they are made in the US. Also, it could be easily replaced by an 88B and there goes your vibration. Brand bashing... really old.

[image: View Post]afennell, on May 14 2009, 12:03 PM, said:

[image: View Post]BusyLittleShop, on May 14 2009, 12:36 PM, said:

[image: View Post]afennell, on May 14 2009, 09:24 AM, said:

Motorcycle engines are designed to produce high power abruptly for short periods of time.
Negative... Motorcycle engines are engineered to produce high power for long periods of time... not
short... magazines have run a number of motorcycles at full throttle 12,000 rpms for 24 hours in the
quest of a record... trying running an aircraft engine at 12,000 RPMs and see what happens...

Yeah, but will a motorcycle engine run above 75% throttle continuously and achieve 2000 hours of time between overhauls. Would you bet your life on it?

With clean air and oil, there is a pretty good chance.

Do you want the smoothest inline MC engine to put in a plane, Try a CBX1000 six cylinder engine. Straight sixes are legendary for their smoothness. With the CBX, you get adequate power with the smoothness, plus no watercooling system to worry about, just a smallish oil cooler. Honda also packed up the engine and it's ancilliaries tight enough so it's not so long. I wouldn't go for the Benelli Sei engine though (if you can even find those anymore), I would think it's not as reliable and it did not make nearly as much power as the CBX engine did.
BTW, you also get the great growling engine sound unique to the CBX.!

Beck
95 VFR

[image: View Post]BusyLittleShop, on May 14 2009, 12:36 PM, said:

magazines have run a number of motorcycles at full throttle 12,000 rpms for 24 hours in the quest of a record...
I think I did that with my '91 Acura Integra when I was in my early 20's ; )

[image: View Post]afennell, on May 14 2009, 01:03 PM, said:

[image: View Post]BusyLittleShop, on May 14 2009, 12:36 PM, said:

[image: View Post]afennell, on May 14 2009, 09:24 AM, said:

Motorcycle engines are designed to produce high power abruptly for short periods of time.
Negative... Motorcycle engines are engineered to produce high power for long periods of time... not
short... magazines have run a number of motorcycles at full throttle 12,000 rpms for 24 hours in the
quest of a record... trying running an aircraft engine at 12,000 RPMs and see what happens...

Yeah, but will a motorcycle engine run above 75% throttle continuously and achieve 2000 hours of time between overhauls. Would you bet your life on it?

Wouldnt you be running the engine at a continuous 8500 rpm and have to gear down the revs for a prop? 2000 hours continuous? No I wouldn bet my life on it.

MD

Just thought of something reading through the posts. When I was working on a plane a while ago for Bede, I believe I was told that you do not want high rpm engines on a plane. If this is the case, then the rest makes sense. The HD engine has much lower RPM, which makes it fine to use. That means that any and all sport bike motors are no good. As much as that rotax is going to cost you, plus the TBO, I would go for it over an unproven engine. Its coming down to the fact that the sport bike engines which are powerful and light enough run at too high of an rpm, and the bigger engines, such as honda's 6 cyl is going to be too heavy.

RV has a plane, possibly the RV-10, which can use the LS1 engine. Just throwing that out there.

I've seen kit planes that have used lawn mowers for engines. Why not pull something off a small cruiser which will most likely be air cooled and light enough to get the job done. I know the Rebel 250 is a single carbureted, air cooled engine that is pretty light. Of course it vibrates, has 16 hp, and red lines at 8k rpm but moves a 450 lb bike + 250 lbs of rider and passenger with no problem.

Cruiser engines are usually pretty good for low rpm, high torque, air cooled combinations.

I recently had an introductory PPL lesson in a plane classed as a microlight (all-up weight less than 670kg, IIRC). The instructor spent a lot of time talking about the plane, making references to similarities to motorcycles, etc. The plane was powered by a 1300cc Rotax flat four, and was only ~100hp. However, it was a fairly slow-spinning beast, with maximum revs around the 5k rpm mark. The prop was geared down 2-1, so was only spinning at half that. The engine didn't seem especially smooth, and felt MUCH more vibey than a VFR.
Plane engines are subject to frequent tear-downs and part replacement as a matter of course. Ideally you want a fairly simple engine (easy to pull apart) that revs relatively slowly, and which produces maximum torque at close to the normal cruising speed.
If you used a bike engine, you'd really need to gear it down a lot, and - if it was a VFR - so that it was turning over at around 7-8k rpm at the plane's cruising speed. That'd leave some power in reserve, be sitting in a relatively smooth part of the rev range, and also its normal duty cycle would be such that the engine was relatively unstressed.

SOMEONE is smokin' wackyweed!!


(Not that there's anything wrong with that)

Wow, lots of replies... I still have the two VFR 750 engines and thought that the high revving part would only be used for takeoff. I hadn't given the water cooling part much thought but you are right that it would be something else to worry about. When you are 50 miles out over the trees, silence is the last thing that you want to be hearing. The entire reason that most experimental aircraft builders are choosing alternative engines is that they are more affordable. The Rotax engines are about $20k in Canada, combined with the accident reports of 6 out of the 11 accidents involved Rotax engine failures, I thought to use an alternative engine.

I will be building the aircraft from scratch via a set of plans and videos. It will be my first build, so it probably won't be completed for at least two years. My idea is to build the main fuselage first, so that I can mount an engine on it and do some static thrust tests of whatever engine that I decide on. Reliability, vibration, and fuel economy, all play an important role in the final decision. The guys who were doing it with HD have managed to find a newer HD model that has counterbalance weights added to remove most of their vibration. There are lots of engine designs around. Moller uses a variant of the Mazda rotary in his flying car but he is using a ducted fan arrangement. I guess that the word experimental aircraft really has deeper meaning than I was originally anticipating.

You aren't necessarily going to be using "full throttle" on take-off and landing. You will increase the rpm, but you will also change the prop pitch. If I remember right, LSAs are allowed to have either constant speed props or retractable landing gear, and I believe I read on the CH701 page that it has a constant speed prop.

Side note. The EAA is offering a free 6-mo membership.

Experimentals do take a long time to build. Good choice going with something with a nice, low stall speed. The only kit plane I know that has a short build time (200hrs) is the BD-17/18, but that's a different category of plane.

[image: View Post]Iwerk, on May 14 2009, 05:27 PM, said:

Wow, lots of replies... I still have the two VFR 750 engines and thought that the high revving part would only be used for takeoff. I hadn't given the water cooling part much thought but you are right that it would be something else to worry about. When you are 50 miles out over the trees, silence is the last thing that you want to be hearing. The entire reason that most experimental aircraft builders are choosing alternative engines is that they are more affordable. The Rotax engines are about $20k in Canada, combined with the accident reports of 6 out of the 11 accidents involved Rotax engine failures, I thought to use an alternative engine.

I will be building the aircraft from scratch via a set of plans and videos. It will be my first build, so it probably won't be completed for at least two years. My idea is to build the main fuselage first, so that I can mount an engine on it and do some static thrust tests of whatever engine that I decide on. Reliability, vibration, and fuel economy, all play an important role in the final decision. The guys who were doing it with HD have managed to find a newer HD model that has counterbalance weights added to remove most of their vibration. There are lots of engine designs around. Moller uses a variant of the Mazda rotary in his flying car but he is using a ducted fan arrangement. I guess that the word experimental aircraft really has deeper meaning than I was originally anticipating.

Keep it moving forward!

.... what about.. a ... little turbine?

You can always go for a Canard type design so you can have a better chance of gliding it back to the ground if whatever engine you do put in, decides to take a nap during flight.

Beck
95 VFR

Use a moto guzzi twin. also, a CBX motor would weigh half as much as the aircraft.


Guzzi has all the advantages of a HD, but is 90 degrees and smooth. Also shaft drive to simplify things.
[image: Posted Image]

[image: View Post]timmythecop, on May 15 2009, 12:25 AM, said:

Use a moto guzzi twin. also, a CBX motor would weigh half as much as the aircraft.


Guzzi has all the advantages of a HD, but is 90 degrees and smooth. Also shaft drive to simplify things.
http://www.aerotech-....com/gucci2.jpgWell then, why not try a CX500 engine. At least it will be more reliable than a guzzi engine wil ever be, plus you will have the power output oriented the right way already. If you want more power, then dig up a CX650 turbo instead, but, of course, it will be more complicated and harder to get parts for.
The CBX1000 engine is indeed heavy, but I'm sure it makes enough power to get itself off the ground with no problem, plus you can always "soup" it up much easier that a V4. You will just have to build a stronger, more efficient airframe.

Beck
95 VFR

Find an old Goldwing engine. 1200,1500, 1800. Thats a perfect powerplant for an aircraft. When HondaJet gets off the ground I would love to see them get into the light sport biz and drop their baby into it. That would be a beast!!

afennell, May 14 2009, 10:03 AM

BusyLittleShop, May 14 2009, 12:36 PM

afennell, May 14 2009, 09:24 AMMotorcycle engines are designed to produce high power abruptly for short periods of time.

Negative... Motorcycle engines are engineered to produce high power for long periods of time... not
short... magazines have run a number of motorcycles at full throttle 12,000 rpms for 24 hours in the
quest of a record... trying running an aircraft engine at 12,000 RPMs and see what happens...

Yeah, but will a motorcycle engine run above 75% throttle continuously and achieve 2000 hours of time between overhauls. Would you bet your life on it?

Yes and Yes... 2000 hours at 80 MPH = 160,000 miles... I think you will find a number of motorcycle
owners in the world with 160K + on their clocks without needing a overhaul...

Beck, May 14 2009, 06:06 PMYou can always go for a Canard type design so you can have a better chance of gliding it back to the ground if whatever engine you do put in, decides to take a nap during flight.

Beck
95 VFR

I've watched the CH701 videos of dead stick landings. It seems to perform really well.

When I was down near Orlando last year, I stopped by Wallaby Ranch hang gliding school and saw a few odd looking Australian tow planes that had emergency chutes built in. It was a vertical tube installed behind the seat and the chute was anchored to the lift point of the tow plane. The tube had some sort of charge in it, so that with one pull of a cord and the chute would propel out of the top of the plane and slow the plane down for a relatively safe landing. This sounds like cheap insurance for an experimental aircraft.
http://www.wallaby.com/about.php

Keep it moving forward!

.... what about.. a ... little turbine?
[/quote]


I thought about a homebuilt turboprop. I bought a model hobby aircraft book that shows how to build a model turboprop engine. I wonder how reliable this would be and how well the plans would scale up to something useful for the CH701. Lots of options out there but I'm not sure which way to go. Plenty of time to kick a few ideas around.

http://www.vortechonline.com/Merchant2/mer...uct_Code=JB6804

This is a bad idea.

For a first project, you need to stick with a tried and true combination of motor/airframe.

If you aren't an EAA member, find a local and join up. Ask lots of questions and listen.

Good luck.

I have seen light aircraft with subau engines. The boxer layout is perfect. However the engine neeeded a gear reducer so the prop wont spin over 3k rpm.


I have a gl500, same engine as the cx. 53hp and 50ft. lbs. It's a rather weak engine but bulletproof. Some blokes over the pond have over 500k kilometers. They use them for courier duty.

Lee 2002, May 15 2009, 03:30 AMThis is a bad idea.

For a first project, you need to stick with a tried and true combination of motor/airframe.

If you aren't an EAA member, find a local and join up. Ask lots of questions and listen.

Good luck.

I agree that a first project should be a tried and true combination of motor/airframe. I chose the airframe for just that reason but I am having difficulty with the thought of forking out $20,000 for a Rotax engine. I chose to scratch build the CH701 so that I could keep the cost of the airframe as low as possible while learning how to actually build something with my own hands. This way, when I dent up my new aircraft, I'll know just how to fix it. As for flying experience, I have flown sailplanes, hang gliders, 28 years in multi-million dollar flight simulators, etc. (I repair/maintain simulators as an occupation.) I also fly radio control aircraft. There aren't too many things that I can't fly. I work for the airlines, so I fly for the cost of lunch when I really have to get somewhere in a hurry.

As for the EAA membership, or COPA or RAA or any of those other organizations, I'm having a bit of trouble understanding what they have to offer. Other than getting a pin, a hat or an e-newsletter, I don't really know what these organizations offer that can't already be located somewhere on the internet. I once belonged to COPA. I proudly displayed a gold wing sticker on my car window for years. I seriously didn't understand the benefits of belonging to these organizations. I just want to fly my own homebuilt aircraft out in some farm field for fun. I don't want to deal with air traffic controllers or any other form of government dictators. Flying for the fun of it, while not bothering anyone.

I really like hang gliding. It gives me a sense of freedom. The down side of hang gliding is that I always need an aerotow or have to jump off a mountain. I looked into power assisted hang gliding but discovered the CH701 along the way and decided that this 580lb aircraft made more sense to me than using my legs for landing gear. The CH701 can be fitted with floats or skis and it even has a folding wing option so it is easily trailered and can be stored at home in a garage or shed.
If a non-aircraft engine is experimentally tested in a proven airframe, it could be very dangerous and life threatening. Hang gliding is potentially dangerous too, if you happen to get too far away from the LZ and there are too many trees in your way. I guess that life is all about adventures and people will have to take certain risks as a trade-off for certain pleasures. Flying an untested engine would probably be done safer if it were tested within a close distance to the airfield. The Wright brothers started it all, so I guess we will just have to take technology one step at a time and see where we end up.

Beck, May 14 2009, 07:39 PM

timmythecop, May 15 2009, 12:25 AMUse a moto guzzi twin. also, a CBX motor would weigh half as much as the aircraft.


Guzzi has all the advantages of a HD, but is 90 degrees and smooth. Also shaft drive to simplify things.
(IMG:http://www.aerotech-poland.com/gucci2.jpg)

Well then, why not try a CX500 engine. At least it will be more reliable than a guzzi engine wil ever be, plus you will have the power output oriented the right way already. If you want more power, then dig up a CX650 turbo instead, but, of course, it will be more complicated and harder to get parts for.
The CBX1000 engine is indeed heavy, but I'm sure it makes enough power to get itself off the ground with no problem, plus you can always "soup" it up much easier that a V4. You will just have to build a stronger, more efficient airframe.

Beck
95 VFR

w/ the CX, yer back to the watercooling issues.

i'm still holding to the fact that the vfr engine is not the engine to use in the plane.

high-rpm engines are a no-no
maintenance will be more on a bike engine than a rotax
vfr w/100k @60mph = 1600 hrs. Rotax/lycoming TBO 1500-2000 hrs
. but how many vfr engines make it to 100k with no work or rebuilds or valve checks
shaft system/gear reducer
all the wonderful plumbing
high altitude with a carb engine => how do you adjust your fuel mixture
heat dissipation on the exhaust valve w/unleaded gas is not that good.

It just doesn't make sense to me to use a motorcycle engine.

The EAA is offering a free 6 mo. membership right now. Get it, get discounted tickets to oshkosh, and go.

What is the problem with watercooling? the plane would be moving, so you would have airflow. The radiators don't weigh that much, and could be positioned in such a way as to be extremely efficient.


I say go for it....millions of people die in their beds having never done anything.

Tightwad, May 15 2009, 11:17 AMWhat is the problem with watercooling?

Hole a rad, blow a hose, clamp comes loose, t-stat malfunctions come to mind. All non-issues with air-cooling.

Also on hour ratings, I'd think in the real world a tiny experimental plane is going to get flown at most about 10 hours over a weekend and at best only a couple of times month when you consider other things like work, weather, family commitments, seat/flying comfort in a cramped cockpit with no heating/AC, etc. 20hrs/month=240hrs/yr@60mph=14,400miles/yr My point being that this is probably very similar to recreational motorcycling and low hours/miles are the norm.

Tightwad, May 15 2009, 05:17 PMWhat is the problem with watercooling? the plane would be moving, so you would have airflow. The radiators don't weigh that much, and could be positioned in such a way as to be extremely efficient.


I say go for it....millions of people die in their beds having never done anything.

I agree, watercooling has advanced to the point that it's almost as passive a system as aircooling.........uhhmmm.......as long as you check your thermostat once in a while (IMG:style_emoticons/default/rolleyes.gif) . but most reliable motors (like the one on the Honda CX500/650 do come with watercooling systems that do not give owners trouble for close to the life of the engine, just as long as regular/required maintenance is apllied to it. Watercooling also results in an engine that is more thermally efficient and generally more powerful, because it is not as effected by engine heat at all ranges like aircooled engines are, plus mechanical tolerances are tighter so the engine will produce power more efficiently.

Beck
95 VFR

Lee 2002, May 15 2009, 02:30 AMIf you aren't an EAA member, find a local and join up. Ask lots of questions and listen.

Iwerk, May 15 2009, 05:45 AMAs for the EAA membership, or COPA or RAA or any of those other organizations, I'm having a bit of trouble understanding what they have to offer.

Your situation may be somewhat different, since you work for airlines. But the guys at work may not enjoy talking plane on their days off. To them, it may just be a job. They don't want you pestering them on every situation you encounter. You need to join a local to network the knowledge database that the members have.

That is why I said, "find a local and join up." Nearly every Chapter will have usually have a Airframe and Powerplant guy. Depending on the size of community you live in, he may very well be the guy who will perform you final inspection. You want him on your side. You don't want the first look by an A&P to be at your final. You will have "unlimited" access to his knowledge once you make good friends. This guy has joined a club to talk planes, and will gladly listen to all your first-timer questions. He isn't the guy you are pestering at work.

Nearly every Chapter will have some old codger who has "been there" and "done that" three or four times since 1946. They love nothing more than to talk airplanes. They have more knowledge in their left pinky about building planes than all the books, videos and YouTubes combined. The "codger" in my local is ~78 years old, has built 4, owned 6 or 7, and is currently restoring one - even though he can't pass a medical. This guy knows and loves planes and is looking for someone to share that interest.

YoshiHNS, May 15 2009, 09:52 AMi'm still holding to the fact that the vfr engine is not the engine to use in the plane.

(IMG:style_emoticons/default/+1.gif) Get to the basics here.... I have never heard or read of anyone using a VFR engine in a homebuilt. You will need to engineer, develop, fabricate, test, evaluate, modifiy your own gearbox. Or modifiy an existing box to mount up to a VFR crank. I don't know your background, but you are biting off a HUGE chunk. You'll be chewing for a long, long, time. There is no off-the-shelf, bolt-it-on gearbox for what you are saying you want to do.

For very few people is "the journey" the same as "the destination." You are most likely doing this because you want to fly. Don't force yourself to become a mechanical engineer/R&D tech along the way.

Again, good luck.

what about using a big-bore VW lump? You can get a built-up turn-key for under $3k; they are all but Lycomings anyways. and a lot cheaper to maintain.

I had a co-worker when I lived in Wisconsin, who built and flew his own plane. He was also a member of EAA and attended the EAA convention in Oshkosh, WI, religiously, flying in his creation to join the flock of Experimental Aricraft fans from all over the world. This guy was a very basic "nuts and bolts" mechanic that mostly dealt with "low tech" tractor trailer and truck deisel engines and hydraulics for concrete pumps that we used at our work as general contractors. He got around most of the more complicated engineering by buying a "kit" plane (A 2 seat, fiberglass, canard design with fixed landing gear) and basically followed the manufacturer's recommendations for powerplants (IIRC, he used some two stroke Rotax engine as recommended by the manufacturer and other owners) and avionics.
I would say that the safest way to get into experimental aircraft building and flying is the way he took. A lot of these "kit" planes are already well proven and have a good existing resource base for other builders and fliers so you don't have to do too many (dangerous?) "shot in the dark" guesses on what components might work best up hundreds or thousands of feet above the ground.
Everyone at work new him as this simple, quiet guy named "Wayne" at work, but my boss found out the hard way (accepted an invitation to fly with him one weekend) how he turns into the Aerobatic "Red Baron" once he is in his plane.

Iwerk, May 15 2009, 06:45 AM

Lee 2002, May 15 2009, 03:30 AMThis is a bad idea.

For a first project, you need to stick with a tried and true combination of motor/airframe.

If you aren't an EAA member, find a local and join up. Ask lots of questions and listen.

Good luck.

I agree that a first project should be a tried and true combination of motor/airframe. I chose the airframe for just that reason but I am having difficulty with the thought of forking out $20,000 for a Rotax engine. I chose to scratch build the CH701 so that I could keep the cost of the airframe as low as possible while learning how to actually build something with my own hands. This way, when I dent up my new aircraft, I'll know just how to fix it. As for flying experience, I have flown sailplanes, hang gliders, 28 years in multi-million dollar flight simulators, etc. (I repair/maintain simulators as an occupation.) I also fly radio control aircraft. There aren't too many things that I can't fly. I work for the airlines, so I fly for the cost of lunch when I really have to get somewhere in a hurry.

As for the EAA membership, or COPA or RAA or any of those other organizations, I'm having a bit of trouble understanding what they have to offer. Other than getting a pin, a hat or an e-newsletter, I don't really know what these organizations offer that can't already be located somewhere on the internet. I once belonged to COPA. I proudly displayed a gold wing sticker on my car window for years. I seriously didn't understand the benefits of belonging to these organizations. I just want to fly my own homebuilt aircraft out in some farm field for fun. I don't want to deal with air traffic controllers or any other form of government dictators. Flying for the fun of it, while not bothering anyone.

I really like hang gliding. It gives me a sense of freedom. The down side of hang gliding is that I always need an aerotow or have to jump off a mountain. I looked into power assisted hang gliding but discovered the CH701 along the way and decided that this 580lb aircraft made more sense to me than using my legs for landing gear. The CH701 can be fitted with floats or skis and it even has a folding wing option so it is easily trailered and can be stored at home in a garage or shed.
If a non-aircraft engine is experimentally tested in a proven airframe, it could be very dangerous and life threatening. Hang gliding is potentially dangerous too, if you happen to get too far away from the LZ and there are too many trees in your way. I guess that life is all about adventures and people will have to take certain risks as a trade-off for certain pleasures. Flying an untested engine would probably be done safer if it were tested within a close distance to the airfield. The Wright brothers started it all, so I guess we will just have to take technology one step at a time and see where we end up.

I have spent alot of time talking to aircraft builders in selecting my plane Cozy MKIV. I have a friend up at the Brampton Flight Centre who has built 5 planes. I was asking him if I should install a new or used engine. I think his answer summarized the cost saving argument the best. "Do you really want to pour your heart and soul in building a plane and then turn around and put a crappy old engine in the thing." Get the engine that the plane was designed around. If cost is the issue you might want to go with a cheaper airframe design. There are some great steel tube and fabric planes that are far cheaper than the CH701. Aluminum is expensive. Wood planes are also much cheaper to build.

Also, my same friend installed a Rotary engine in a plane just for fun but said that he didn't recommend it. There are so many builder who install two engines in their planes. First they install a cheap alternative engine, spend 6 months or more trying to get it running properly. Then the second engine is the correct engine for the aircraft design after they give up on their first idea.

My last job had me working with lots of experimental aircrafts as well as redesigning one. To be honest, a lot of the experimental planes I saw frightened me on how poorly they were built. They did fly, but I would not want to be in one. The big thing was fastening hardware. You wouldn't believe how many people just went out to ace and got the cheapest hardware they could find. Half those planes didn't even have the nylon locking nuts! So spend the money, do it right, and help me sleep better at night.

FotoMoto, May 15 2009, 09:44 AMHole a rad, blow a hose, clamp comes loose, t-stat malfunctions come to mind. All non-issues with air-cooling.

Air cooling is simple but it's issue is unwanted heat... with liquid
filled coolant passages cylinder and head temps are held somewhat near
coolant temp of 195F... on air cooled engines the base of the cylinder
can rise to 302F and the head and the top of the barrel to 446F... the
piston is in contact with those high temps so it may run hotter yet...
uncontrolled piston temps requires compression ratios to be lower in
air cooled engines... that is the main reason why motorcycle engines
switch to liquid cooling and they solved most of the problems
associated with malfunctions...

BusyLittleShop, May 15 2009, 09:51 PMAir cooling is simple but it's issue is unwanted heat... with liquid
filled coolant passages cylinder and head temps are held somewhat near
coolant temp of 195F... on air cooled engines the base of the cylinder
can rise to 302F and the head and the top of the barrel to 446F... the
piston is in contact with those high temps so it may run hotter yet...
uncontrolled piston temps requires compression ratios to be lower in
air cooled engines... that is the main reason why motorcycle engines
switch to liquid cooling and they solved most of the problems
associated with malfunctions...

At 50% cruise power (this scenario), puh-leeeeeze. A performance aircraft, sure.

I don't disagree with the physics as I know the cbx motor previously brought up in this thread has heat issues with cylinders 3 and 4 when pushed in drag racing (back in the day) and power falls off.

I love my VFR.............but you've got to be suicidal if you're going to trust your life to the R/R!!

BusyLittleShop, May 15 2009, 10:51 PM

FotoMoto, May 15 2009, 09:44 AMHole a rad, blow a hose, clamp comes loose, t-stat malfunctions come to mind. All non-issues with air-cooling.

Air cooling is simple but it's issue is unwanted heat... with liquid
filled coolant passages cylinder and head temps are held somewhat near
coolant temp of 195F... on air cooled engines the base of the cylinder
can rise to 302F and the head and the top of the barrel to 446F... the
piston is in contact with those high temps so it may run hotter yet...
uncontrolled piston temps requires compression ratios to be lower in
air cooled engines... that is the main reason why motorcycle engines
switch to liquid cooling and they solved most of the problems
associated with malfunctions...

I always thought at least some of the reason we have liquid cooled engines was due to noise regulations. I have only seen one (1) oil cooled-still technically air cooled-GSXR motor blow up in many years of racing and not for a lack of trying.

in regards to cooling. leaded fuel helps a great deal with cooling as well as lubrication

YoshiHNS, May 15 2009, 11:47 PMin regards to cooling. leaded fuel helps a great deal with cooling as well as lubrication

I guess if you were running a bike motor in your plane you would prolly be using Cam2, right?

no idea really. The rotax will use leaded fuel, but also has fuel mixture controls so you can have proper fuel flow at altitude. The 750 engine is carbed. Thats a big problem in terms of fuel mixture. You would most likely just run a higher octane unleaded, but that's the least of your problems

squirrelman, May 14 2009, 10:17 PMSOMEONE is smokin' wackyweed!!


(Not that there's anything wrong with that)

Note to self: never ride in front of squirrelman.

FotoMoto, May 15 2009, 07:59 PMAt 50% cruise power (this scenario), puh-leeeeeze. A performance aircraft, sure.

I don't disagree with the physics as I know the cbx motor previously brought up in this thread has heat issues with cylinders 3 and 4 when pushed in drag racing (back in the day) and power falls off.

You can throttle back to 50% to save your engine but you'll need 100% for takeoff and want 75% for
cruise... it's no fun pooping around the big open sky... but as piston ring grooves rise beyond 347F
oils coke and rings stick. Back in the 30s and 40s when the majority of piston aircraft engines were
designed and they haven't changed through the ages... piston crown temp could not be reduced... so
the designer located the rings further down the piston away from the heat... Now look at the modern
liquid cooled motorcycle engine and you'll see rings within 2mm of the piston top but 55 years ago that
had to be as much as 4 times farther down... Oil cooling was critical to the success of large air cooled
aircraft engines which employ a 3rd of the air for oil cooling as they did for direct cooling of the fins...

all this talk about aircraft.

....I am leaving for the airshow at Andrews AFB right now. A-10s, Raptors, F/A-18s, P-51s and your United States Air Force Thunderbirds in their F-16 Fighting Falcons (Viper).

Oh boy

how about a BMW boxer 1100/1200 engine? torque engine all the way, modern injection, 4 valve heads, air cooled STILL NOW, oriented in the right direction, FLAT! and a nice sound with a right exhaust, lineair power delivery ass hell and dead reliable if given the proper run in and maintenance

(IMG:http://andyw-inuk.smugmug.com/photos/393030084_KjTqS-S.jpg)

I think I would go with an engine that makes more torque and less revs than a motorcycle engine, seems torque is the name of the game for flying a prop plane.

timmythecop, May 17 2009, 10:27 AMall this talk about aircraft.

....I am leaving for the airshow at Andrews AFB right now. A-10s, Raptors, F/A-18s, P-51s and your United States Air Force Thunderbirds in their F-16 Fighting Falcons (Viper).

Oh boy

I think the only thing better sounding than a V-4 is a P-51 Mustang Rolls Royce V-12 at full song!!!!!