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Iwerk - n/a
11-Feb-06, 12:50 AM
I have been looking for an engine recommendation for my Canair 300 that I plan to build starting next week when the plans arrive. The designer Ron Fishlock has recommended the target weight of the engine be approximately 80 lbs and a power range of no less than 28 horsepower. I am looking for a relatively fuel efficient engine, so my latest searching is directed towards motorcycle engines.



A friend at work has two Honda V4 engines from VFR750F motorcycles that he is will to part with for a very low price. I am wondering if anyone has any experience with putting motorcycle engines into hovercraft? I am going to go have a look at the Honda V4 engines in a few days and try to size them up. From the information that I have found on the internet, they appear to be in the 100 HP range with 53 ft/lbs of torque. I haven't got any idea how much they weigh yet but I will be attempting to remove the transmission to lighten up the final weight. I will then use pulleys and a drive belt system to adjust my final drivetrain. The complete motorcycle would weigh in at approximately 460 lbs. The motor and transmission would probably weigh at least 200 lbs. Removing the transmission would probably put the engine weight at 100 lbs. I am speculating alot here but until I actually have a first hand look at the engine, I won't know anything. 100 HP in a small 2 seater hovercraft, is quite a bit of power. Any speculations or advice would be appreciated. This will by my first hovercraft build, so I am kind of in the dark here.

Superwedge - n/a
11-Feb-06, 05:10 AM
Have a look at Charles Dixon's attempt to use a Honda 1996 VFR 750 Hopefully you will not have his problems but you may get some ideas from his site.

http://www.speedjunky.net/Articles/Viper/Page3.htm (www.speedjunky.net/Articles/Viper/Page3.htm)



Tony.W.

Don83000 - n/a
11-Feb-06, 08:19 PM
The 400 honda is not very heavy even with the gearbox still fullof its bits I can lift one easy and I ain't no Jeff Capes and if you leave the box in one piece you can simply drive off the output shaft as we have with the ZX 600 Ninja and use a smaller top pulley as you have a built in primary reduction plus you can use the clutch making starting easier. The Ninja goes approx 50 kilo. I was going to use the 400 honda but could not find one at the time.

srn4 - n/a
12-Feb-06, 01:07 AM
Have you thought about the BMW k100 engine...thats a really nice engine!

Iwerk - n/a
12-Feb-06, 02:59 AM
The problem with the BMW engine is that I live in Canada and BMW engines are really rare over here and really expensive if you can find one. I have to look for an engine that is relatively easy to find parts for and won't break my bank account. But I will keep that engine model in mind, if I happen to find one. Thanks...



------

srn4

Have you thought about the BMW k100 engine...thats a really nice engine!

Ian Brooks - n/a
12-Feb-06, 06:49 PM
I took a look at motorbike engines a while back - came to the conclusion that anything in the 40-50 hp range and 4 stroke would weigh in somewhere in between 55 and 70kg (120 - 150lb). In the end I went with a 503, at 32 kg (70lb) bare, its a very light way to get 50hp.



Trouble with any two stroke is they are /very/ thirsty. The 503 can burn 5 galls an hour on full chat.



Have you thought about the 3 cylinder Geo (Swift in the UK) engine? Should be cheap from a sc**pyard, comes in at about 130lb for around 45hp. If the plans allow for 80lb, then you will need to make some significant changes to use something heavier, to get the trim right.



The other option would Kohler or Briggs V twins, which come in about 100lb, but are usually around 25 hp unless tweaked.



Ian

Iwerk - n/a
12-Feb-06, 08:39 PM
Hi Ian,



I am starting to lean in the direction of the Geo engine. I have a '94 Geo 3 cyl, 1 litre engine parked in my driveway. I bought the car last year for $600 and it is in good shape. I was planning on using it this winter because my VW diesel Jetta doesn't like the cold weather. Problem was, it never got cold this winter, so the car never got used. It would be a shame to take apart this car but the local sc**p yard has lots of these cars. I could always use my Geo as a reference engine to get the sc**pyard version running properly. I found this link on the internet that has got my interest. http://www.ultralightflyer.com/metrogeo-aircraftenginevideo (http://www.ultralightflyer.com/metrogeo-aircraftenginevideo.html). html





-----------

Ian Brooks



Trouble with any two stroke is they are /very/ thirsty. The 503 can burn 5 galls an hour on full chat.



Have you thought about the 3 cylinder Geo (Swift in the UK) engine? Should be cheap from a sc**pyard, comes in at about 130lb for around 45hp. If the plans allow for 80lb, then you will need to make some significant changes to use something heavier, to get the trim right.



Ian

Sean Atterbury - n/a
13-Feb-06, 12:01 PM
I say stick to a flying engine, subaru, rotax, raven, you cant go wrong and they are built to rev flatout for longer periods, plus cooling them is less an issue.

http://hovercraft.org.uk/images/icons/smiley_icons/icon_smile.gif

Ian Brooks - n/a
13-Feb-06, 06:14 PM
Wow!!! I can't believe that the BB starred out the word "sc**pyard" - well known onscenity!



Ian

GavinParson - n/a
13-Feb-06, 08:42 PM
is it cos it contains c**p?

Hovertrekker - n/a
14-Feb-06, 12:24 PM
(testing ...) The word sc**pyard is spelled s c r a p y a r d http://hovercraft.org.uk/images/icons/smiley_icons/icon_rolleyes.gif

GavinParson - n/a
14-Feb-06, 04:03 PM
No, no, no. They're not designed to run flat out for long periods. Rotax for example only recommend maximum power for a couple of minutes, i.e. for take off.

You want an engine that you don't need to run flat out so you keep it reliable. Eg, if you want 80hp, get a 100hp engine and run it at no more than 80% throttle. Cruising speed should be half throttle or less.



Gavin

Sean Atterbury - n/a
15-Feb-06, 06:03 AM
Around 5 000, flat out .. http://hovercraft.org.uk/images/icons/smiley_icons/icon_eek.gif



then 6 000 http://hovercraft.org.uk/images/icons/smiley_icons/icon_surprised.gif



then 6 600 http://hovercraft.org.uk/images/icons/smiley_icons/icon_biggrin.gif ye baby ye



kabooooom http://hovercraft.org.uk/images/icons/smiley_icons/icon_cry.gif



rebuild http://hovercraft.org.uk/images/icons/smiley_icons/icon_razz.gif



Off we go again http://hovercraft.org.uk/images/icons/smiley_icons/icon_twisted.gif



Will it break? http://hovercraft.org.uk/images/icons/smiley_icons/icon_rolleyes.gif



Its all about the emotion, see.. http://hovercraft.org.uk/images/icons/smiley_icons/icon_cool.gif

Iwerk - n/a
21-Feb-06, 10:00 AM
I weighed the Honda V4 VFR 750cc engines that my friend was trying to sell to me. They weighed in a 170 lbs. each dry. Just a little bit over the 80 lb. limit for my Canair 300. I had a line on a Polaris 440cc snowmobile engine for $200 but by the time that I got there, it was sold.