brillo

http://www.autoweek.com/news.cms?newsId=103342

Kinda interesting. Looks like the pending death of the IC piston engine may be greatly exagerated. Somebody please tell Al Gore for me.

Aoshi Shinomori

Lol. Good find. Most of this stuff goes over my head anyway though. I need to read it through a bunch of times, while looking at the howstuffworks page :p

globi

Here's a picture of a camless engine from 1904:
http://www.daimler.co.uk/history/html/sleevevalve.htm

No need to wait until 2008 just visit a car museum.

KYLiquid

interesting

s13lover

2008 huh? Wankel did it in 1936 on a Daimler-Benz DB601 V-12 for the German government. It was a production engine too. Here is an excerpt from The Wankel Rotary Engine :

"...Wankel's disk valves covered the top of the cylinder bore. The outer periphery of each disk was cut as a gear, each disk driving the one next to it. They were driven b y a pinion gear off of the crankshaft at one-fourth engine speed. Each disk had two opening that would pass over circular exhaust and intake ports. The ports were fitted with a two-piece split ring seal patented by Wankel earlier. The outer periphery was sealed by a piston ring sort of affair set into a groove in the head, Combustion pressure was allowed to work on both sides of the disk, keeping it from being forced too hard against the seal elements of one side or the other another. After extensive testing, the disk-valve DB601 went into production to be installed in fighter planes for the Luftwaffe.
...By arranging the disk to drive one another, as Wankel did, valve stems, valve springs, rocker arms, lifters and camshafts can all be eliminated..."

BaronVonBigmeat

This is probably one of those things that won't be really practical on a large scale until we move to a 42V electrical system. Being able to essentially swap cams on the fly from streetable to race-car lumpy would be cool though. But not quite as cool as spherical rotary valves, which also yield less friction, but with much greater airflow (while enabling higher compression via exhaust valve cooling to boot).

s13lover

Interesting, but I see one major problem with this design - the 14:1 compression. First, that compression is NOT emissions friendly. The CO and HC might be reduced; however NOx will be through the roof. The higher exhaust temps could also damage a catalyst converter. Second, I would assume that the motor would have to run premium gas which would limit the market for the motor. Third, I don't think the oil would last too long with that hot of a combustion chamber to cool. Fourth, is the cost involved in building a reliable motor with that much compression (i.e. - forged everything).


edit: I just watched another of the videos where he says 17.8:1 for the compression. He also claims 2700 moving parts for a 855ci motor's valve train. I don't even know where to start with that claim. He also claims 0 HC and CO readings for the test vehicle. I also like this pic: http://coatesengine.com/eGallery/pag...aced-parts.htm. It looks like multiple heads in the top pic with even the head bolts. He claims this all gets replaced by 2 parts. Yet this pic: http://coatesengine.com/eGallery/pages/components.htm shows 65 parts, not including head bolts (granted it is a different motor, but you get the idea) This guy likes his BS.

millyard

hah, I bet they have a completly custom electrical system, likley several hundered volt, with a supercapacitor to supply the extremely high bust current draw of the valve actuators

since the valves have to be held in place with a lot of force they probably have a latching mechanism so the valves do not have to be energised when open and possibly even a energy regeneration system for when the valves close, well thats how I would do it