Talk:Sleeve valve

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I am currently researching sleeve valve engines. Is there any body out there doing anything new with sleeve valves?

I would also like to hear from anyone with first hand experiance of the Bristol sleeve valve engines; i.e. pilots or engineers or those on the production line.

How reliable were they and were they realy oil thirsty?

I didn't notice the post above until just now, and since you didn't register I don't have an account to reply to. Hopefully you'll see this.

The "oil thirsty" issues are not theoretical, they are entirely practical. Basically engines are nowhere near "pefectly circular" and as a result pistons to not fit cleanly into the cylinder. Instead the piston rings are placed around the piston and run until they scrape off the irregularities on the cylinder, which is deposited in the oil. This is called "breaking in" an engine, and you have to change the oil very soon after it is new.

With a sleeve valve the piston rings do not run on the cylinder wall, but the sleeve. This means that they scrape off a repeating N pattern in the sleeve as the piston moves up and down, so there is always somewhere on the sleeve that is not sealed. The oil blows past this hole and is burned.

However that was 50 years ago when a milimeter was considered the height of accuracy. With modern construction techniques and materials engines don't even have a breaking in period any more. The same techniques would "solve" the problems of the sleeve valve design, but there simply isn't any money in it.

Maury 00:15, 28 Dec 2003 (UTC)

Contents

[edit] Sleeve valve

is there anyone who has a drawing of a sleeve valve

Found a good description with drawings here: [1]
GalFisk

[edit] Cleanup

How about starting with some basic things like telling us at least something about what it is first, before you get into advantages and history? Gene Nygaard 07:29, 7 October 2006 (UTC)

[edit] sleeve, separate openings for I and E

or just one? CorvetteZ51 14:05, 16 July 2007 (UTC)

I'm not sure if this is universally true, but for one engine with which I'm slightly familiar, there were some (I forget the number) dedicated openings in the sleeve for inlet OR exhaust and one opening that opened inlet and exhaust in turn. (If I can find out more, I'll add it). In fact, the drawing linked above shows exactly this layout. 217.205.121.71 18:12, 17 August 2007 (UTC)

[edit] Port size query

"the speed at which air can enter and exit the cylinder is defined by the size of the duct leading to the cylinder and varies according to the cube of the RPM"

Is this true?