Rotary valve technology

All that has to do with the power train, gearbox, clutch, fuels and lubricants, etc. Generally the mechanical side of Formula One.
autogyro
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Joined: 04 Oct 2009, 15:03

Re: rotary valve technology

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Carlos wrote:Rotary valve 4 stroke inlet/exhaust port timing may exhibit similarities with two stroke I/E timing.

Two Stroke Tuners Manual
By G. Jennings
http://www.vintagesleds.com/library/man ... ndbook.pdf

Insight:
"The advantage of a rotary valve is that it enables the two-stroke engine's intake timing to be asymmetrical which is not possible with two-stroke piston port type engines. The two-stroke piston port type engine's intake timing opens and closes before and after top dead center at the same crank angle making it symmetrical whereas the rotary valve allows the opening to begin earlier and close earlier.

Rotary valve engines can be tailored to deliver power over a wider speed range or higher power over a narrower speed range than either piston port or reed valve engine. Where a portion of the rotary-valve is a portion of the crankcase itself it is particularly important that no wear is allowed to take place."

From:
http://en.wikipedia.org/wiki/Two_stroke_engine

Make note of Uniflow Scavenged Engine timing diagram.

Thread Belatti kindly researched and specifically recommended:
malbeare:
"Valve timing Intake open 20° BBDC 520° close 60° ABDC 240°
Duration 440° (this is not a mistake)
Maximum port area at 20° ATDC
Exhaust open 40° BBDC 500° close 60° ATDC 60°
Duration 280°
Maximum port area at TDC 0°
Overlap 260° (this is not a mistake)"

Well worth your time to study previous thread.

Also G Jennings section on ignition timing.

OT - Interesting saying 'Axe to grind' - here we answer that with the folk wisdom 'It's easy to hang a corpse' and of course the modern equivalent ... 'It is what it is.'

Good Luck


http://en.wikipedia.org/wiki/Rolls-Royce_Crecy

You can place the port timing anywhere you like with this baby
Estimated 4,000 hp from 26 liters, imagine it with electro magnetic drive and control on the sleeves and 19.000 rpm.

xxChrisxx
44
Joined: 18 Sep 2009, 19:22

Re: rotary valve technology

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WhiteBlue wrote:It sounds like a very valuable technology to have for the new direct injection engines. So advantage are:
  • less mechanical losses compared to current technology
  • no obstacles inside the cylinders for gas fill, less disturbance of fuel charge and ignition
  • no objects in the air stream, better air fill and aerodynamic losses
I would be surprised if Ferrari, Merc, Renault, VW and Cosworth would all miss out on having such an advantage. I expect VW to enter F1 if the regulations allow a I-4 design.
Disadvantages are the same as with all rotating applications. Sealing will be a total bitch.

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rotaryvalveman
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Joined: 24 Jun 2010, 11:46
Location: Brisbane

Re: rotary valve technology

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Agh, the seal question. I wondered when this one would come up and yes you are right, if you look at in conventually. Take your view out of the engine realms and look from other areas of engineering and you will see it is actually rather esay. Remember I said that I had actually done this once already and the solution is actually in every car or motorbike on the road today but not in the most obviouse place. it is also umbelievably cheap and turns one automotive problem into my sealing solution. The last one I made sealed statically at 300PSI and dynamically at over 17.5:1 compression. this was due to an error in the lad doing the CAD work and forgeting the domed piston but it proved a point.

No, sealing is not my problem. homeing in on the correct valve timming for the next prototype is as it will save me costs if I can get closer to optimisation as possible but I suppose I am going to simply have to take an educated guess, which is not my style but I have to start, or restart, somewhere. I am going to just have to be a little conservative. See, Damned politics again.

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WhiteBlue
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Joined: 14 Apr 2008, 20:58
Location: WhiteBlue Country
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Re: rotary valve technology

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Which kind of engine config would make rotary valves more affordable? My guess would be in line four?
Formula One's fundamental ethos is about success coming to those with the most ingenious engineering and best .............................. organization, not to those with the biggest budget. (Dave Richards)

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rotaryvalveman
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Joined: 24 Jun 2010, 11:46
Location: Brisbane

Re: rotary valve technology

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well, for me, a cylinder head that has only two moving parts and less components in a four cylinder than current technology can get down to on a single is always going to make it affordable. that was another point. Colin Chapman (Lotus) always said that to make it better you should add simplicity and it beggers belief to me that we have over complicated things so much over the last 100 years. Which ever engine you ask to convert, it will cost to do the first one, obviously but after that, they are as cheap as scrap to knock out. a single or an inline four or six still only has two rotors and a pair of seals for each cylinder, the head it's in and a couple of pullys. it's less complicated than even the Bishop design or the Coates design.

So, to answer your question, I am doing the single cylinder first to hone in on the best timmings and flow rates for relitivly high road levels of performance and will then transfer data to a car engine just to get reliability and emmisions data. any configuration is possible just as a single cam design can be converted to twin cam 4-valve heads have in the past.

xxChrisxx
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Joined: 18 Sep 2009, 19:22

Re: rotary valve technology

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rotaryvalveman wrote:Agh, the seal question. I wondered when this one would come up and yes you are right, if you look at in conventually. Take your view out of the engine realms and look from other areas of engineering and you will see it is actually rather esay. Remember I said that I had actually done this once already and the solution is actually in every car or motorbike on the road today but not in the most obviouse place. it is also umbelievably cheap and turns one automotive problem into my sealing solution. The last one I made sealed statically at 300PSI and dynamically at over 17.5:1 compression. this was due to an error in the lad doing the CAD work and forgeting the domed piston but it proved a point.

No, sealing is not my problem. homeing in on the correct valve timming for the next prototype is as it will save me costs if I can get closer to optimisation as possible but I suppose I am going to simply have to take an educated guess, which is not my style but I have to start, or restart, somewhere. I am going to just have to be a little conservative. See, Damned politics again.
I don't see what solution you came up with to have a sustained seal, perhaps you can elaborate. But rotary seals just don't last (at full sealing) especially if you have ANY sliding what so ever the wear rates just shoot through the roof. So tolances have to be stupidly tight, even then you don't get a seal as good as a poppet valve.

This is simply beucase the positive pressure in the cylinder actively aids the metal-metal seal, which you don't get in a rotary.

The sealing isn't a problem per se, it's just a characteristic of the valve. Just like high stresses due to reciprocation are an inherent trait of poppet valves.

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rotaryvalveman
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Joined: 24 Jun 2010, 11:46
Location: Brisbane

Re: rotary valve technology

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As I said, the solution is poetically simple. I did try to go down the "tight tolerence and special materials" route years ago. Then I saw the work done by R C Cross and was allowed to look at some of his old engines. then the penny dropped. Do not fight the laws of Physics, work with them. Turn one problem that is nothing to do with engines and use it to solve your own problem. This I did. In fact, the solution is so simple that the few people who have seen it laugh and say the same thing in that, "why did no one see this before" which is what I keep saying, but I am glad they have not.

All you say is correct, which is why I am not doing it that way. No I cannot share how I have done it but I will share the results after we get going and cut metal. this will not be for about 12-14 weeks or so but hey, I have waited almost a decade to have another go so a few more weeks won't hurt.

PLease don't wish me luck as I think a dose of hard work and honesty is much more important. Luck is for those who don't do it for themsleves. Just keep pushing me to get it done.

Carlos
11
Joined: 02 Sep 2006, 19:43
Location: Canada

Re: rotary valve technology

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Autogyro; thank you for the reference http://en.wikipedia.org/wiki/Rolls-Royce_Crecy ... an extraordinary engine and development programme, very good to meet an overview of the project. Two stroke technology definitely deserves consideration for future applications.

@rotaryvalveman - Interesting reference to Colin Chapman as Lotus Engineering also developed a rotary valve patent in latter years; also the current freeware Lotus Engineering Engine Simulation software download might be of value.

F1_eng
4
Joined: 05 Aug 2009, 11:38

Re: rotary valve technology

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I really think you should look down the CFD route, certainly for future work. I think I know the company that you mentioned, was is Advantage CFD? How long ago did you approach them?
Either is was a long time ago, or they must have not wanted the project. I work for an F1 team and am involved with CFD, in particular CFD methods at a very senior level, it's not my main work but it does take up some of my time. I was mainly involved with engine/powertain work previously but have deviated for some time. I could perform this kind of analysis fairly easily, or you could also look at a 1D analysis of the system, or maybe a 1D-3D coupling of the more complex areas.

You might be sad to hear, but large companies don't work on a purely experimental basis usually because the costs can deviate very quickly and you end-up losing control of projects. Also it's a very old-fasioned approach which usually means you have to itterate to solutions. Good modeling of the system would allow you to run and predict behaviour of 50 different timings over-night, with very accurate results, even 1D code can yield very acceptable results.

What sort of running times have your previous engines seen?

100bhp loss for a DFV valve-train is nonsense.

It is certainly very very interesting technology which has massive scope for different directions of development, it would be crazy to think of what could be achieved, particularly performance wise. I would be a little worried about your confidence with the sealing issue, especially long term. Maybe the sealing device could be an easily changed component.

You should look at the basics like mean flow coefficients for your system now to achieve a reasonable timing initially. It's certainly not a criteria I would build a prototype to though.

Would be interested in helping you out with some things but I am fairly heavily tied in with contracts, IPs and consultancy things.

Good luck.

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rotaryvalveman
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Joined: 24 Jun 2010, 11:46
Location: Brisbane

Re: rotary valve technology

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thank you for the offer of help and some very usefull information. I do sgree that the more profesional and skilled a company gets, the further away from grass roots it is and then it can't do the small projects. We are going to model everything and try to get some analysis done but as prototyping is now so cheap it looks like that building in the ability to change timmings is going to save heaps of time and money. I suppose technology has come full circle in development terms. firstly it saved time by proving things out electronically and now it is as cheap to make something as it is to design. 3D printing has made this possible.

There are so many teams that have had a go at this I think that the main problem is the cost to any size company is relitive to the size of that company and so they need to keep staying afloat and can't afford to deviate to much before going bust. Good business is concervative business I suppose.

only the little individual has the ability to risk his own time but there is the paradox. those who can afford the time don't have the resourses. those that have the resourses have a business to keep afloat so blue-sky projects don't pay the bills.

the seal is a very qick change item. it will wear, even in my design vut is replacable in the same time as, say, the same time as changing two spark plugs. well within the scope of a 50k miles service interval.

again, time will tell. I hope to have it on a dyno by christmas. I will cost out some CFD but if it's too expensive, we will just build a few itterations and give it a go.

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rotaryvalveman
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Joined: 24 Jun 2010, 11:46
Location: Brisbane

Re: rotary valve technology

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to answer the question on running times, that is an interesting point.

we got the prototype made a few years ago and it would run for about a minute and seeze the exhaust rotor which would strip the drive gear. we tried everything to stop the seal and rotor from binding by trying different materials but never more than a few minutes running.

it was not until we thought outside the box and moved away from the "tighter tolerence" route and gave things places to go to and restricted cooling to the head (we actually had too much cooling) that we finally got everything expanding at the same rate.

then we had hours of running. unit would idle as quiet as a mouse but this was right at the end of the project and, it has to be said, after the money ran out due to the funding company pulling the plug just before they themselves went bust. Optimisation was the next job after mechanical reliability but unfortunatly I had to go and get a job so that was just left for the next thing if ever we wemt back to it.

malbeare
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Joined: 21 Jan 2005, 12:50
Location: Australia

Re: rotary valve technology

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Hi,
I am waiting for the outcome of the federal court before I start posting again
https://www.comcourts.gov.au/file/Feder ... 07/actions[/url][/url]

cheers malbeare

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rotaryvalveman
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Joined: 24 Jun 2010, 11:46
Location: Brisbane

Re: rotary valve technology

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i looked at the link but can only see that is has something to do with tha Jack Brabham company. I hope that this goes well for you and that justice is done but what relevence that has to this thread I can only guess. I look foward to your outcome.

from one "little guy" who just took a company to court here and won after some bully tacticks (nowt to do with engines, just real estate) and won, all I can offer is that truth and honesty usually wins out.

As I said before, there is always more politics than engineering in any project. this is because of the inherent greed in society but that is a differnt forum I suppose.

on the seal matter, yes I have an easyly replacable item that is discarded but after all the percived problems the industry has on the matter, we have had to come up with one that at least has some long term reliability so 50K Kilometers is our first goal. I think that is realistic and achievable. the results on the last tials some years ago were incourageing anyhow.

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PlatinumZealot
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Joined: 12 Jun 2008, 03:45

Re: rotary valve technology

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Rotary valve man. If already read the previous threads on this topic (I don't know if it's still there)I tried to design a rotary valve myself. My design ended up converging to look like the "Coates" rotary valve.

The toyota BRV is interesting but it has a lot of parts and the intake and exhaust valves are the same. I would post my version here if It's still online that is. I hit a brick wall because the cylinder head was not strong enough.
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