spunky
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| posted on 22/2/05 at 01:30 PM |
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Re-inventing the wheel or next generation motor?
Interesting idea,
http://www.new4stroke.com/
Apologies to those that have seen it.
John
[Edited on 22/2/05 by spunky]
The reckless man may not live as long......
But the cautious man does not live at all.....
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flak monkey
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| posted on 22/2/05 at 01:52 PM |
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That idea isnt new...
Where I worked over the summer they had a 2 stroke car with 2 crankshafts and 12 pistons...ie the same design as that (i know that is a 4 stroke
though). Its a car that was built by the company.
I am assuming the patent ran out on that idea a long while ago as they built the car at the turn of the 20th century.
Here's a pic of it:
Nice idea, but not new...not by a long way!
David
[Edited on 23/2/05 by flak monkey]
Sera
http://www.motosera.com
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Spyderman
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| posted on 22/2/05 at 02:40 PM |
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Certainly an interesting concept, but I don't see it as the next stage in engine development. 
Judging from the animation there is a limit to it's valve timing. The timing cannot be adjusted without also altering the compression ratio.
The valve/piston stroke is tied to other valve/piston stroke, so can't be adjusted separately, other than by using sleeves and a different size
piston/valve.
Using a separate crankshaft for each valve would enable valve timing to be independent, but would also add a great deal more mass (rotating mass at
that) to an already overweight engine (compared to with normal valves).
It is highly probable that the high torque figures mentioned in the site that caused the crank failure were as a result of the greater rotating mass
together with the higher revs being used!
Hasn't it already been proven that greater efficiency is obtained by reducing the rotating mass rather than increasing it? The Bike engine
springs to mind here together with most modern short stroke oversquare engines.
I am not trying to knock the guys inventiveness, just merely trying to point out what I see as limitations to his project.
I would still be keen to watch it's developments though! 
Terry
Spyderman
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Hellfire
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| posted on 22/2/05 at 03:07 PM |
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Sorry for a minor hijack but I always preferred the car with this engine...
That (my friend) is showing my age... it the car which first caught my attention as a young'un it is a NSU RO80.
[Edited on 22-2-05 by Hellfire]
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DarrenW
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| posted on 22/2/05 at 04:09 PM |
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Having a crank for the pistonvalves at the top must surely make the engine taller. Where do we put the kent cam?
Hellfire - what car is that?
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Hellfire
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| posted on 22/2/05 at 04:29 PM |
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See my edit Dazza... 
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Fifer
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| posted on 22/2/05 at 05:18 PM |
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Agreed on the rotary RO80. it was way ahead of it's time
I got an RX8 in September and it is great. !2 k miles already and a set of back tyres at 10.5 k !!!
Mind you, I think that is due to my sons switching off the traction and booting it everywhere they go, dont know why I let them drive it, maybe cause
its a company car and if they rack the miles up, i get a new car quicker. Every 2 years and 4 months at present i hit 100k miles and the car goes back
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Peteff
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| posted on 22/2/05 at 08:06 PM |
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I helped fit Ford Corsair V4 engines to a couple of RO80s way back when. They were a bit unreliable, to say the least, and very expensive to fix. The
repairs were usually short lived as well, hence the transplant. They were alright if you lived at the top of a long hill.
yours, Pete
I went into the RSPCA office the other day. It was so small you could hardly swing a cat in there.
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Findlay234
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| posted on 22/2/05 at 08:08 PM |
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surely the next evolution in road cars is to follow suit with the race cars and use pnuematic or hydraulic valve actuation with a forced opening and
forced closing. Having a system like this would also allow a constant variation in timing and lift, possibly to the extent that it negates the need
for a throttle body.
Also here at loughborough theyre working with lotus on these ideas and the idea of laser ignition. I think this allows you to burn the mixture at the
optimum point within the chamber and also get rid of the stubby spark plug which inhibits flow and mixing.
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Hellfire
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| posted on 23/2/05 at 12:31 AM |
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Audi are developing an engine with a crank not mechanically linked to the valves. The valves are electronically actuated via a seperate cam driven by
a stepper motor. This gives infinately variable timing and also lift to suit driving style. There are also no plugs to ignite... it works very much
like a diesel engine in as much as compression fires the fuel. It's in early stages... but a working model has been manufactured.
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spunky
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| posted on 23/2/05 at 12:39 AM |
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I agree with all the above but its good to see a privateer going it alone and trying new ideas. Got to admire the guys dedication.
I like the idea of of the piston valves increasing the swept volume and assisting in compressing the mixture, but the valve crank and rods would
surely take a hammering at detonation and have to be pretty hefty to have any longevity.
Certainly bike engine development seems to leave the car manufacturers standing, consider the Desmo system that Ducati have been using for years. 200+
BHP from a 1 litre engine is considered a starting point.
Incidently, don't know if any of you guys are into jet bikes/skis but the top end machines are now running supercharged 4 strokes making around
220hp, and they are designed to make big torque at low revs, (water is a bit heavy to shift...) Now thats an engine begging to be dropped in a
Locost.
John
The reckless man may not live as long......
But the cautious man does not live at all.....
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krlthms
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| posted on 23/2/05 at 02:08 AM |
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Unless I am missing something, which is quite likely, it looks to me like a variation on the desmodromic mechanism.
I would have had the two crankshafts rotating in opposite directions for obvious reasons.
KT
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spunky
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| posted on 23/2/05 at 09:09 AM |
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It is a similar concept to the Desmo, but a lot simpler, as Ducati use conventional valves and rockers with an extra camshaft to close the valves.
Been in production since 1960's.
One thing is certain, if anyone developed a genuine breakthrough in 4 stroke design it would be swallowed up and shelved by GM, Ford, Fiat or one of
the petrochemical cartels...
John
The reckless man may not live as long......
But the cautious man does not live at all.....
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