Rotary Valve Heads!!!

[Guest aspemino]

I've heard that early early willys knights had a similar thing where a pipe rotated and a hole in the pipe would line up with another opening. Pretty cool idea for back then huh!

[Nismo280zEd]

ok... so i'm a very visual hands on learner and i'm having trouble understanding EXACTLY how these valves work. Also i would think if your engine is spining at 14k you would have to have a new way of igniting the fuel. At that point you might as well just keep the spark plug lit up the whole time like a "glow plug" seems like this might be better suited for a diesel engine?

 

Also if your running that high a rev... y not make an engine with 3 or 4 huge clyinders, relatively short stroke.. put these roatry valves on the top, and use some glow plugs and spin the hell outta the thing?

i don't know.. it's late maybe i'm getting dillusional.

-Ed

[Moridin]

They should have some pictures on the website I posted. Instead of a poppet valve, on a normal engine, it uses a oval-type ball that spins in place of the poppet valve. There are openings on the roller valve that allow things in and out of the motor.

[Mack]

I would think that making these damn things seal up would be easy, with ceramics and cryogenically treated metals. ceramics for the ring seal in the head, and cryogenically tread the "ball" valve for the increased wear resistance.

 

I had an interesting Idea one night, and I put it on paper and had it notorized,so if you steal it, I'll sue your pants off! lol!!

 

it goeslike this

 

get the biggest, nastiest camshaft you can find, then, this is the tricky part, youd have to "modify" a hydraulic lifter and have a way to vary how much lash is in the valve train. I've got it worked out on paper,but can't explain it without a picture. Its kind of like the difference between advertised duration and duration at .050". notice how much it cuts down on duration and lift? well, if you put a lot more lash into it, you could turn a WILD cam into a MILD cam, then just dial out the lash as you see fit for more lift AND duration as the RPM's rise or the throttle is squeezed. kind of like Vtec, or even closer to the new BMW 750(i think) variable ratio rocker arm, but still different....... enough rambling, lol

 

McAdam

[baddriver]

Mack,

 

I think what you are describing is the theory behind Rhodes' lifters, a bleed-down lifter that was advertised as making wild cams more streetable. The lifter bleeds down while lifting the valve, increasing the lash and effectively shutting the valve sooner at low RPM. At high RPM the lifter has less time to bleed down, and so acts more like a regular hydraulic lifter. I used a set of theses on a 400 sb that I built in my younger days. I used a huge 310', 510 lift cam, but I wouldn't say it was 'streetable'. The fact is that roller lifters do the job better by changing the limits of the cam grind. (but I couldn't afford roller lifters back in those days!) The Rhodes lifters never seem to have caught on, and I haven't seen them advertised in a long while.

[Mack]

yeah, i have heard of those. they were talking about like shaving 7 degrees off of the duration, I am talking about 20 to 30 degrees. I will work on drawing up some stuff in photoshop, It'll make more sense when you see diagrams. Itd be pretty sipmle to set up. It uses a stepper motor and some grears. I originally came up with it as a way of retro fitting our venerable SOHC heads with some sort of valve timing and lift control. that was my main concern, seeing as how there are no DOHC or even crossflow head for us. Just wanted to level the playing feild.

 

McAdam

[Guest bluex_v1]

I have a two stroke model plane engine that has a rotary valve sort of arrangement where the crankshaft itself is slotted and acts as the valve. I never really did get how it worked...not too fuel efficient at any rate.