Different Types of Valves

[Kosiba]

I keep seeing different designs for intake and exhaust valve, and I'm wondering if making them in a model engine is worth anything, The first design I have questions about is the rotary valve. In my minde there are 2 types of rotary valve, the type that Daniel Hunziker has on his single cylinder and V8, where a part of the valve is hollow to allow for the gearing to be the same as a 4 stroke engine from the crank to the cam, and the other design where the crank has to spin 4 time for the valve to spin once.

The second type of rotary valve

The head design for the rotary valve pictured above.
Are there any reasons besides the difficulty to machine these that would make it impractical to use? From my viewpoint I can see the reduction of force it would take to move the springs and maybe some difficulty having compressions, but the other rotary valve design has been proven to work, so why not try this one?

The last type of valve design I have questions about arose from this video () where there are 2 cylinder sleeves that move independently from one another, one sleeve acting as the intake valve and the other as the exhaust, what would be the downsides of this design, the guy in the video says that the only issue he has with it is starting it, and he says that this is because the engine starts with a low compression, but that once it builds some heat it can really get going, I feel that if that is one of the main issues then using it on a nitro engine, where the engine can get hotter much quicker would remedy this issue, any thoughts?

Screen capture of him explaining how the engine uses the sleeves as valves.


Glad to hear any thoughts on this!

 

[GreenTwin]

I have seen a number of exotic engine designs, and I have to suspect that they were looking to build the proverbial "better mouse trap", and at the same time were probably trying to circumvent existing engine patents.

Odd engines are very intereting from a functional standpoint, and if your interest is in building unique engine styles, then these types of engines are a good idea.

If you want a fully functional and reliable engine, then I would recommend sticking with the designs that have been tried and proven over many years.

The only odd engine I have seen make it into successful commercial production, and become a highly functional and reliable engine, is the Dake.
For certain functions like hoisting, which require no dead centers, and an engine that will reverse very easily and quickly, a Dake is an excellent choice.
The Dake was also used in mines, since it is totally enclosed, and used on ships to hoist the anchor, with the totally enclosed design being perfect for the salt water spray on the deck of a ship.
The Dake was ahead of its time, and appears to have been derived mostly from a Roots design from 20 years previous.

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[timo_gross]

I found this on short search, it helped me to understand.