13 replies to this topic

[Speedman]

Movie
http://shareplace.com/?8156041C3

Arcobat-Document
http://shareplace.com/?B5BD978010

[Greg Locock]

Interesting. The GN is Guy Negre, infamous promoter of the Air car. Th W12 has rotary valves and does look nice and compact. Pity it never ran in anger.

[desmo]

Cool. I actually at one time had a better picture of the rotary valves for that engine but it has seemingly gone missing.

I guess we'll likely never again need worry about seeing anything similarly daring or innovative or interesting within the current spec engine world of the so called "pinnacle of motorsport".

[cheapracer]

I remember that engine actually being in a car and running, (I didnt look at the stuff above) I give credit to anyway who achieves that even if the results aren't specatcular.

http://www.coateseng...the_future.html

http://www.thetrutha...counting-begin/

[gruntguru]

http://www.coateseng...the_future.html

Quote from the first two paragraphs of the above link.

"In the late 1960s and 1970s, most vehicles combustion engines in the USA were running at a compression ratio of 12 to 1, which resulted in an engine efficiency of approximately 35 percent. . . . . . . . The answer to this problem was to lower the compression ratio of all engines to 10 to 1 or lower, thus reducing efficiency of the combustion engine to approximately 24 percent."

A gross exaggeration of the effect of such a CR change - I had to stop reading there.

[Speedman]

Cool. I actually at one time had a better picture of the rotary valves for that engine but it has seemingly gone missing.

Would be very interesant.



Who has pictures of the crankshaft and rods from this engine?

Edited by Speedman, 19 February 2010 - 11:53.

[Greg Locock]

He hired an F1 team (ATS judging by the photos) and dropped the engine in. It failed to qualify, that was the end of that. All his PR material says he is an F1 engine designer, it leaves out the gory details.

I like the idea of rotary valves I must admit, imagine how compact a 2.4 W-12 or W9 (?) would be.

[SteveCanyon]

I like the idea of rotary valves I must admit, imagine how compact a 2.4 W-12 or W9 (?) would be.

Have a poke through The Old Boy Network and see what you can find out about Harold Clisby, from Adelaide.

[Greg Locock]

Have a poke through The Old Boy Network and see what you can find out about Harold Clisby, from Adelaide.

Better than that

http://forums.autosp...w...28535&st=40

[SteveCanyon]

Good find, Greg.

[Speedman]

A better Link MGN W12

[Todd]

Quote from the first two paragraphs of the above link.

"In the late 1960s and 1970s, most vehicles combustion engines in the USA were running at a compression ratio of 12 to 1, which resulted in an engine efficiency of approximately 35 percent. . . . . . . . The answer to this problem was to lower the compression ratio of all engines to 10 to 1 or lower, thus reducing efficiency of the combustion engine to approximately 24 percent."

A gross exaggeration of the effect of such a CR change - I had to stop reading there.

Most vehicle in the US in the late '60s, early '70s did NOT have 12 to 1 compression ratios. A few did, but they were the highest performing, solid lifter factory hotrods that generally weren't made in the hundreds of thousands. When leaded fuel was regulated out of circulation, compression ratios dropped into the 7.5-9 to 1 range. Power and effiency were lost, but the massive reduction in efficiency described involved emissions controls in addition to about an average 2 point drop in compression ratio. The small Mercedes V8 is a good illustration. The 3.5 liter 1971 models produced considerably more power than the later 4.5 liter versions while using little more than half as much fuel.

[gruntguru]

Most vehicle in the US in the late '60s, early '70s did NOT have 12 to 1 compression ratios. A few did, but they were the highest performing, solid lifter factory hotrods that generally weren't made in the hundreds of thousands. When leaded fuel was regulated out of circulation, compression ratios dropped into the 7.5-9 to 1 range.

You forgot to mention that CR has been climbing ever since, and 11:1 is very common these days. Efficiency improvements diminish rapidly from here up.

[Todd]

You forgot to mention that CR has been climbing ever since, and 11:1 is very common these days. Efficiency improvements diminish rapidly from here up.

I didn't forget, I just didn't consider it something that needed to be specified to point out that their claims for engines of 40 years ago in the US were wrong. I think my car has an 11 to 1 compression ratio. It also has a higher specific output than any US car of 1970 and gets better mileage than any of them that made 200 net hp. But it doesn't do it with the same technology employed in 1970-1975 SBCs. Incidentally, before NASCAR regulated compression ratios and specified unleaded fuel, engine builders were using compression ratios said to be around 15 to 1 with sophisticated knock sensors and individually controlled ignitions.