Rotary Valve Engines and seals? (design)

Idk if the Hamb is really a forum to ask this on but i figured there are a lot of people on here with a lot more experience and knowledge than me. I could go to a tech or design forum and talk theory all day but im hoping just maybe someones has ran into or heard about one of these engines through the years. the design has been around since the 1892 but no one has successfully sealed the rotors(or they have, but they just don't hold together long enough for practical use).

here is a site on rotary valve combustion engines if some don't know the concept Rotary Valve Engines

my design is Dual overhead rotors.

Anyways, I need some kind of seal between the spinning rotor and its housing so the combustion doesn't blow through the exhaust and intake ports, anyone have any ideas on how to do that? I have 2 ideas on sealing it already that i am going to test but i want to see if i can find any other ideas.

I have I've been researching rotary valve head for about 3 years now and I finally have it drawn up and designed one, I even have a ABS plastic prototype printed from my company's 3D printer sitting on my desk right now, unfortunately i cant provide any pictures right now, its very different design than any other rotary valve iv seen and i don't really want to throw it out on the web just yet, i can tell you though that this head design isn't just rotary valves .

I work for an aluminum foundry and CNC shop with CAM machining so i have full access to cast and machine pretty much what ever i want in any metal. As soon as i work out a few problems i'm going to print out the tooling for a single cylinder prototype, cast and machine it just to test compression and proof of concept.

p.s. i'v already been told many times i going down a very long road

 

Are you talking about the ****el design? Or are we talking like snowmobile rotary valve engines?

 

Good luck on this one....

 

no not ****le, just rotary valves

 

one of the ideas i have involves wear surfaces and compression ring type seal but i'd like to make it as simple as possible to avoid added machining, materials and cost.

 

George Coates produced several different rotary valve cylinder heads for US blocks. He had a big display at the SEMA Show in 1993, but I don't know what happened since then. Google 'Coates rotary valve' for more info....

 

I'v read all about Coates, i have no idea what happened to them either, website still up but looks like it hasn't been updated since 93, can't find any videos, info or pricing on the details of their engines. I believe they still hold the patent for dual overhead.

I ran across someone in Australia on a F1 forum that supposedly has a solution to the seals but he hasn't disclosed exactly how yet.

http://www.f1technical.net/forum/viewtopic.php?f=4&t=8671

 

****el was involved in the rotoray vavle concept AND the rotary piston designs.
His expertise was in sealing the moving parts to avoid the high heat transfer and combustion gas contact. ****el came up with the oil spray for both engine designs but the rotary valve had an inherated problem of fouling sprakplugs. The use of ceramic seals in the rotary piston engine allowed it to achive higher "combustion" chamber pressures and thus higher output. I witnessed a single "cylinder" ****el engine test for the military a few years ago that was very interesting. A ceramic rotary valve "intake port" with ceramic sealing rings may be the answer......

 

there was a kit available over here for the holden "grey" motor, made by a bloke called dunstan. sorry i can't offer you any more info i just remember seeing it in a magazine. i think i've still got i somewhere i'll see if i can find it and if its got any useful info

 

found a link with some info, theres a tech sheet about half way down the page. it says they used sealing rings inset into the head.

http://fefcholden.org.au/forum/index.php?topic=14965.0

 

Interesting... I used to have an early Mazda rotary engine mine was a screamer, so small the starter & carb ( it had a 4 barrel carb ) were the same size as the block... even Mazda couldn't keep seals in them for more than 40,000 miles don't know what the RX-8 had for seals ???

however ( & more relivent to your post ), since those days I've gotten some practical expirience with rotary air locks... if I understand correctly, since you are not "building" a rotary motor, only rotary heads ??? maybe look down the path of rotary air locks a little...

I'm not an engineer, but would think seals you're after would be carbon fiber composites, or ceramic based???

 

Here's a photo of the Coates heads....






Click on this link to see a video of how the Coates rotary valve concept works:

http://cnettv.cnet.com/coates-spherical-valvetrain/9742-1_53-32534.html

 

I remember seeing this, but for the life of me couldn't remember who the hell had made it.

Thanks for the info.

 

Seems like Coates was / is on to something good here.

 

Several people have spent lots of time and money in the last hundred years trying to solve this problem. I use to day dream about it 50 years ago. New materials. Computer machining. Maybe now is the time. Good luck. I would love to see someone make a workable kit like this. Put you right in there with Ardun.

 

Ill look into the ceramic bearings but they are very expensive i believe and i want to avoid oil spray for sealing because the more oil u burn the more exhaust emissions go up.

i'm working with the owner of a local race engine building shop that specializes in turbo diesel truck pulling and builds most the drag race engines in the county, he'll be able to help me out with ceramic stuff which i know very little about. I have no idea how id be able to ceramic coat the port and it not interfere with tolerances or machining the head. I also have to worry about rotary lock from carbon buildup.

Im looking into possible hard-coating in aluminum for extra thermal resistance and plan on pouring hypereutectic aluminum(16-24% silicon, most aluminum is around 5-8%), which have higher than normal thermal resistance from normal aluminum resulting in tighter tolerances. My design also enables uniform cooling of the rotors but i can't go into deal about it.

I'v read from a second hand source the cost for a coats head is around 15k :/

That video is a bit miss leading though, the reason rotary valves can run higher compression is because of the absence of the exhaust poppet valve not so much the ceramic coating although it would help. Rotary runs higher compression because they can run a lot cooler so u don't have premature detention even on low octane fuel, i can't image what it would run with 110 race gas .

Ya i know its be tried for a long time, iv even read articles of it tested in top alcohol dragster back in the 80's.
http://www.northernthunder.com/rotary.html

Advancements in metallurgy, design, simulation and machining definitely help though, i have access to 4-axis 3D machining and soon 5-axis although it wont be true 5-axis but i can still get into some pretty crazy designs.



Ill keep you guys posted on the progress if you like, im going to video and do***enting everything i do, the advantage i have over most that have tried though is that i know how to make all my own tooling for molding and casting, and once i have the CNC code written i can make as many as i want with only the cost of material .

 

Coates current website:

www.coatesengine.com

 

thats why i said advantage over most of them

 

In the late '70s I was doing some Plasma spraying ceramics on turbine engine hot section parts and my piston tops. Again, I am sure that in the last 30 years they have come a long way in material and technique. But maybe you could allow for a few thousand's build up. Spray your shafts and ports and in some way lap them to proper running clearance. How do you plan to allow for heat growth on the exhaust side?

 

You wouldn't have any links or info i could have about the plasma ceramic coating would you?

The exhaust growth will be calculated into the 3d machining of the housing though, again though my design is much much different than any other rotary valve, even with a plastic prototype and explaining it to people that have been building engines for 30 40 years and know about rotary valve still take a few minutes to grasp the concept(i even painted my ports blue and red to help). I can drastically reduce the thermal expansion though with water jackets, hard-coating the aluminum, use of hypereutectic aluminum and also my head design allows a much more uniform cooling.

 

The only rotary valve engines I have any experience with were 2 strokes. They were pretty awesome though...

 

All the equiptment and training I had came from Metco. Maybe you can google them for some help.

 

My thought was to use SOLID ceramic, not a coating. Expensive, yes, but look at what you are dealing with...direct contact with the combustion gases. Yes, they have been working with this engine design for over 100 years. The Coates engine patent is one of the newest and maybe the way to go with new materials. I can hear it now, 15,000 RPM......

 

Here's one for you. Canadians Bill Phillips and
Don Zimmerman's rotary-valve, top alcohol
dragster- circa 1985 - from a post I made to
another thread on the HAMB a few months ago.

Mart3406
---------------
www.jalopyjournal.com/forum/showpost.php?p=6052748&postcount=81
============================

 

Wasnt it Minerva that had rotary valves in the 20s and 30s? Every one smoked. Interesting project.

 

It strikes me that sleeve valve engines achieve pretty much all the goals of a rotary valve. With the exception of being able to be fitted to an existing block. And have been produced, sold and run with some success. We have all heard of the "Knight" engine. Willys Knight. And some may remember the Super Marine Sea Fury. I believe the fastest piston aircraft ever in production. So maybe it's a better area to do research in.

 

Hey, Dzuari, n Rich;

IIRC, Smokey had at least one, if not two, rotary valve mills. The one I'm thinking of, was a two stroke, used a blower, ceramic head n ceramic tubes for the rotary valve. I'm thinking that this was the 2nd or 3rd adibiatic (sp?)/hot-vapor-type experiment, running rather high internal temps, using some expensive military jet turbine oil. Anyways, the tolerance(s) were in the millionths of inches, like 2-3 ? I think he had trouble getting them machined properly too. But he didn't need seals 'twixt the head n rotary tubes. Hmm...DOHT(ubes)... . Was only 1 1/2 liter engine, maybe less. I think the article, or comment in Ask Smokey, was in PopMech? Can't remember.

Also, IIRC, the sleeve-valve mill required some carboning-up to seal correctly. Up to that point, they did smoke some, but were very quite after that. Another engine that I really like, but they are complicated, & I don't think that they are a very high rpm mill. Could be wrong here. Sure would like to hear, & see, a 15k rpm version at Bonneville... . If Dzuari can solve the sealing problems, he's got a killer on his hands, esp if he can machine up heads on demand, for any type mill. I can think of some rather interesting mills I'd like to see this on... . Doubt I could ever afford one, though... . Nuts...

Maybe a carbon-type seal like a turbo uses?

Good luck. I like the off-beat, & interesting.

Marcus...

 

Its the Holy Grail isn,t it ,people have been trying for years to perfect it in Australia [see earlier post] maybe as technology improves it may happen....

 

The British sleeve valve aircraft engines required a lot of tricky machining and ***embly by highly skilled mechanics.Oil consumption was often an issue.They weren't really more powerful or reliable than poppet valve engines in combat trim.The Brits liked complicated engine designs.......
I believe the Sea Fury's speed was more a result of good aerodynamics and prop design than brute HP.