roton valves

[twinnie]

i was looking though some biggie pages and i came across this http://www.rotonusa.com/ and it's realy one of those why didn't we think of it before things so simple but it should be fantastic it gets rid off camshafts, pushrods,rockers, and valve stem seals! (i wonder if you'll be able to retro fit it...) what do you engine gurus think?

Matt

[bradley]

the rotary valve concept has been around for a long while now, it runs "hot and cold" with popularity.

I think every time up to now the seals have let them down, and they cant acheive a decent service life. But the rotary "wankel" engine took a lot of years to teethe out the probs and is nowdays a great reliable engine, so whoknows - it may just be a matter of time for the rotary valve.

imho, great concept.

[-Scott-]

You still have valve timing substantially fixed by rotating shafts, and the geometry "hard coded" into them.

Hydraulic actuated poppet valves strike me as a much better solution for the future - infinitely variable valve timing, and can be "regulated" to replace the function of the throttle butterfly.

Besides, this quote from Roton has me a little confused.

Because of this, the ignition can be left much closer to or just after T.D.C. than when a red-hot poppet valve is in a race with the spark plug to detonate the fuel.

Retard ignition further? Why?



Scott

[Loanrangie]

The old slide/sleeve valve was a good idea in the early years -1900 - 191? but soon got replaced by the camshaft actuated valves.

[shanegtr]

you used to be able to get a rotary valve head for the old holden grey 6. The red motor pretty much killed all the good aftermarket stuff for the grey due to its better performance

[Beastmavster]

Side valves laster a lot longer than 191x.....


Rotary valves, hydraulic and pneumatic actuated valves have been around a very long time.


The issue is generally the heat expansion and issues sealing them. There is always some new interest whenever a new rare-earth-alloy comes along but nothing seen yet that's in a production vehicle.

[twinnie]

interisting i did think some one must have done it before. f1 cars with there 20,000 rpm redline use pnematic valves as at those speeds a cam would be near useles i spose.

Matt