Lotus CIV. Concept Ice Vehicle

Thought some might find this power configuration interesting.

BMW bike engine, 2 cylinder, 120 hp, 1.15 liter, burns E85, pushes 790lb sled 80 mph.

http://blog.wired.com/cars/2008/08/lotus-on-ice.html

Several sites on the net but nothing specific to performance or design.

I wish i had the money they have to design and build my boats. You would see some dreams come true. I guess i will have to hope for a stimulis package. :lol: Chuck

If I were holding the purse strings you would be first on the list. Thanks for all the hard R&D work you do do.

Cold and snowy here all weekend and the ice to rotten to fish so I did some more searching.

I found a couple of interesting things on this power plant and two cylinder motors in general relating to prop drives. Most all are related to aircraft so there is "some" application for airboats. Kind of like apples and plumbs. (old private pilot).

Here is a post from a thread discussing the BMW (and other) powerplants...feel free to read the entire thread at the following link. http://www.homebuiltairplanes.com/forums/firewall-forward-props-fuel-system/4659-bmw-r1200-motorcycle-engine.html This is just internet talk so take it for what it is worth but there are a few good tech tidbits if you read it all. Warning, not for those with A.D.D. ...which is probably most airboaters. :lol:

This post #20 brought up "torsional vibration" and leads to the company that developed the drive for the sled.

Re: BMW R1200 motorcycle engine

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Hi,
(edited)
There have been some comments about the vibration of these engines at low RPM. I suspect this is more to do with torsional vibration than the engines being unbalanced, however. So I was particularly interested to read the other day about the re-drive of choice among the Europeans, who choose the BMW very frequently to power their aircraft.

"All satisfied BMW-flyers I know are customers of Wilfried Bleidiesel (http://www.takeoff-ul.de). I recently purchased a clutch with a one piece disc from Wilfried. This clutch is proven, not as heavy as the other brands and it matches the endurance of the gear drive."

So off I went to takeoff-ul.de, ran it through altavista.com's on the fly language translator, and was able to glean sufficient information about their redrive and clutch combo to get me really interested. Basically the centrifugal clutch only engages at about 2500 RPM well past the RPM range during which torsional vibration is an issue. The drive is a bit pricy (2500 euro) but in the grand scheme of things, I think this a a great solution.

Duncan

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The link for the drive company is http://takeoff-ul.de/ You can see the sled there as well as airboats and planes. I put the site into Yahoo's BableFish translator but I think I figured out just as much from looking at the pictures.

Just another cogg in the knowlege sprocket.

Clutches sound interesting but not at the cost of quick responce. Around here we have to manuver quickly so we need something that will spin-up and down quickly. Not one for waiting for a clutch to kick in and start to spin. Aircraft can afford to wait a few seconds for a responce...not so good for cutting around an unexpected piece of rebar or car body in the river.

Feel free to send this to the junk yard or to the 4 stroke folder.

What about an electric clutch? Anybody tried one?