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ideola · Joined: 01 Oct 2004 Posts: 15550 Location: Spring Lake MI

There was another post recently about a similar approach, I was going to post there, but I couldn't find it. In any event Revetec, and Australian company, has developed a "trilobate" cam approach to the internal combustion engine. Start here, and take a look at the subsequent content. Don't know how optimistic the claims are, but it's fascinating stuff nonetheless.

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erstwhile owner of just about every 924 variant ever made

Rich H · Posted: Fri Jan 09, 2009 4:37 am Post subject:

Hmm, nice idea, but sadly lacking all the improtant bits we want: bhp, torque, weight and size... 39% efficiency? Great. No good if it produces 20 bhp!
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1994 Lotus Esprit S4 - Work in progress...
1980 Porsche 924 S2 DITC Turbo - Original spec
1978 Homo-Sapiens - Tired spec
1953 Landrover S1 - Pensioner Spec

agfisher · Joined: 09 May 2007 Posts: 484 Location: West Hartford, CT

Amazing!
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1977 924 N/A Martini Edition

Chrenan · Joined: 15 Jan 2003 Posts: 3903 Location: Canada

Interesting. That does seem like a lot of gear teeth to be spinning around intside the sump. I'd hate for one of those teeth to break off and get loose. But I'm no engineer.
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1987 951 - M193 Version for Japan

ideola · Joined: 01 Oct 2004 Posts: 15550 Location: Spring Lake MI

One of their claims is that less RPM is required for peak performance and efficiency, so that may be a factor to consider...
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erstwhile owner of just about every 924 variant ever made

morghen · Joined: 21 Jan 2005 Posts: 9095 Location: Romania

i'm not convinced, in theory it sounds goodish but in reality i think that even if it does work, an engine like this has a short life spawn or if its made to last it will use expensive oil and expensive internal parts...lots of them.
So it might be a bit more effective but there are more internal parts moving and there is much more friction and load transmision from one part to another, the result IMO is alot of the usefull power lost due to the complication of the system and it will cost a fortune to make and maintain.
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Supercharger and EFI kits
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Fifty50Plus · Posted: Fri Jan 09, 2009 8:03 am Post subject:

I'm looking at the pictures and thinking Whee... But I can't help wondering about the twisting torque applied to the "rod" by the off center counter rotating scissor cams. What keeps it straight and what supports the bottom of the "rod"? The writeup mentions hydrolics to keep it straight and avoid piston to wall contact but what keeps it from twisting? How do that work?
Chuck

ideola · Joined: 01 Oct 2004 Posts: 15550 Location: Spring Lake MI

I don't know how, but it apparently does work, at least long enough to do this:

Don't get the wrong idea...I am NOT an apologist for this approach, I just thought it was fascinating.

There are videos of the trike in action at the bottom of this page:
http://www.revetec.com/media_main.htm
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erstwhile owner of just about every 924 variant ever made

PORSCHEV · Posted: Fri Jan 09, 2009 11:17 am Post subject:

Very intresting! Looking at the 3D model in motion I looked mostly at the piston movement itself and that it really ony has a short stroke. I know the inventors claim better torque transfers in this pic.

I wonder if the inventor was to compare with a V12 engine with a similar short stroke what the results would be. I do have to wonder what the mechanical losses are with the gears INSIDE the engine.

The video does not do the invention justice at all. The engine sounds like it is under a load and doesn't have much power at all.
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1976 924
5 lug conversion, 17'C2 wheels,custom body work,327 vette engine.

1978-#53 "D" track racer.

morghen · Joined: 21 Jan 2005 Posts: 9095 Location: Romania

They say that there is no need for higher RPM...its not like they dont want it..its because they cant rev it higher...look at the internals...they are HUDGE at least...and way too heavy. besides the whole ideea is silly.

The picture below is nothing more than a aluminium made model but even so...there are much more load and friction issues with it than with the normal engine. If you want a low rev powerfull and economic engine get a turbo-diesel. For example look for the new 1.4 TDI engine in the new bluetec polo.

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Supercharger and EFI kits
https://www.the924.com

ideola · Joined: 01 Oct 2004 Posts: 15550 Location: Spring Lake MI

There's a big difference between economic and efficient...
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erstwhile owner of just about every 924 variant ever made

tuurbo · Posted: Sat Jan 10, 2009 1:56 am Post subject:

And for guys like me who don't want to piss around with definitions too much, I just say the use of energy in these engines appears pretty sensible. I would think using the design in aircraft would be a good starting point.
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1980 924 turbo, MSD, Meth. Inj, otherwise stock.