Coat's shaft valve engine. - PeachParts Mercedes-Benz Forum

dkveuro · #1 03-24-2006, 07:23 PM

Some of you have seen this, but it's my first time...gotta share...

http://www.coatesengine.com/

I'm still reading the site

....see you there.

.

BamaMB · #2 03-24-2006, 08:50 PM

Interesting. The rotating valve is nothing new. The problem has been creating a seal that prevents blow by. Maybe they have found a solution.

G-Benz · #3 03-26-2006, 07:50 AM

We had a thread on this years ago...the website was more of a prototype interest piece...and like said, the seals would have been the main obstacle to the design.

From the looks of things, apparently that obstacle has been ovecome...

Brian Carlton · #4 03-26-2006, 10:48 AM

Quote:

Originally Posted by G-Benz

From the looks of things, apparently that obstacle has been ovecome...

If M-B can make a tensioning rail that suffers abrasion from the chain for 300K, you would think that the solution for a smooth spherical steel valve would be relatively easy..............

I'll bet it's not a technical problem but a cost issue.

Matt L · #5 03-26-2006, 10:56 AM

Think of the price of changing the timing on that engine. While camshafts and poppet valves have their problems, at least you can tune them fairly easily.

peragro · #6 03-26-2006, 01:28 PM

hmmmmm, no more valve clatter...

Maybe they're using synthetic lubricants and ceramics.

G-Benz · #7 03-26-2006, 08:02 PM

Quote:

Originally Posted by Matt L

Think of the price of changing the timing on that engine. While camshafts and poppet valves have their problems, at least you can tune them fairly easily.

Adjustable camshaft gears? Doesn't Honda's VTEC use the same sorta principle?

raymr · #8 03-27-2006, 11:24 AM

I'm curious to know how the rotating valves handle the explosive combustion chamber pressure. My guess is they use a spring-loaded seal of some kind, similar to a rotary engine. If they do, this engine will be VERY sensitive to any contaminants. ie carbon breaking loose from the piston.

Matt L · #9 03-27-2006, 11:47 AM

Quote:

Originally Posted by G-Benz

Adjustable camshaft gears? Doesn't Honda's VTEC use the same sorta principle?

It would be easy to alter the timing, but both sides (opening and closing) will respond equally. Same as simply offsetting the camshaft in a "normal" engine, which does have its purposes. But increasing the duration is common for performance engines, with a bunch of other work, of course.

Perhaps some sort of computer-controlled eccentric gear could be used between the drive and the shaft to control both the timing and duration. Then you get the timing of an economy engine at partial load, and a nice performance timing when you demand full power. Since these shafts don't push against a 300 pound spring load, it might be possible. Still, the engineering sounds like a real nightmare.

raymr · #10 03-27-2006, 04:35 PM

Another possibility would be to separate the engine breathing from the crank altogether. If the mechanical resistance is low enough, servo motors can rotate the valves at a rate determined by the engine management system.

boneheaddoctor · #11 03-27-2006, 08:02 PM

Quote:

Originally Posted by G-Benz

Adjustable camshaft gears? Doesn't Honda's VTEC use the same sorta principle?

no...Honda has two set of lobes, on the intake cam, one low RPM adn one for high RPM...switched via a solenoid controllin oil pressure. Trust me in that I have been all through a head on one of those as I have a 1.6 Vtec engine pushing 200hp in my Civic. Oh, the Accura NSX has a simmular setup only the exhaust cam is also a dual profile cam.

If I am not mistaken Toyotas VVT may be closer to what you describe, but not familar with that engine.

Hatterasguy · #12 03-27-2006, 10:36 PM

Vtech is pretty cool stuff, it gives a nice kick when you get above 4k or so if my memory serves me.

I am pretty sure MB was doing it before Honda though!