Rotary valve technology

[riff_raff]

Rotary engine valves always sound like a great idea, at least until you run into those "pesky" engineering issues like tribology, friction, heat transfer, sealing, combustion kinetics, etc.

As for that old boogey-man "politics" being the only thing keeping your rotary valve design from achieving commercial success, that's just a feeble excuse. The real reason 99% of the world's recip engines use poppet valves is because the poppet valve has proven to be the best combination of cost, performance, and reliability.

There's no conspiracy. Just the immutable laws of economics and physics.

Regards,
riff_raff

[rotaryvalveman]

riff_raff
I understand your Cynicism and it is easy to say but after getting stuffed for $1.5Million, I am afraid that I have a right to blame politics, especially when I and others such as Bishop, Cross, Gabelish, Vial and P.E.Irving all have documented, hard data to prove it is relaible, economical and clean going back over 50 years. This is going to be my point. If I make a new moden design and cost it out, run it, prove it's credentials for emmisions, my plan is to give it to some struggling race team and let it all speak for itself. this has already been planned for but I assure you, Politics is a bigger player than any engineering element ever will be. You don't get large companies trying to knock down a steel door and rob your design if it wasn't.
Although I brought the subject of politics up, can we please concentrate on engineering.
Tribology is only a problem if you need to lubricate it. I do not now and that is the key. Turn a problem into a solution. Again, that that will be revealed later.

[rotaryvalveman]

On a more technical (and interesting) point, I am going to start with a 230 Degree inlet, 240 degree exhaust, almost no overlap (but that will be adjustable anyhow) and the timming straight up, or assymetrical, but again all that will be adjustable. the airflow I am not going to go over the top on but will allow, statically (on a flow bench) 75% of the inlet flow for the outlet. if I go for about 120cfm of airflow for a YZ250 Yamaha engine then we should have pushed the envelope enough to break something but these are just guessed starting points rather based on a bit of the experience from last time and a chat with some other people who have done other rotary valve heads and are still alive.
I can't see that anywhere is wrong, as such, as it will show us a like for like result if we put the original head back on and coppy the same timing and see what we see. Then, after going in one direction or another, we will learn some more. As we learn, we will post what we find....well, most of it anyhow. can't give the whole game away can we.

[autogyro]

I wish you the greatest of luck rotaryvalveman.
I just thought I should again mention that 'sleeve valve' engines were fully proven in the 1940's and were in reliable service on military operations through out WW2 in both fighters and bombers.
If you equate efficiency with power output per liter. These sleeve valve engines produced nearly three times the power of even four valve per cylinder poppet valved engines and later non operational developments with supercharged stratified charged two stroke sleeve valce engines, resulted in documented results close to five thousand horsepower from 26 liters.
This technology works, is reliable and was prevented from on going development in road and race vehicles because of cost and the politics that you find so detrimental to your rotary work.
Current ic engines in road and race vehicles IMO are many decades obsolete even by 1940's standards. It is one of the worst cases of deluding the public for profit in this and the last century.

[rotaryvalveman]

as a last point on ploitics, this story is not mine but I have heard it so many times, I have confidance in repeating it.
Mr Diesel designed his engine to run on Nut oil or other bio material. The Rothschilds lowered the price of fossill based heavy fuel until it drove the bio industry out of business as it was uneconomic. only then did the fossill oil find it's true economically viable price
True or not, I do agree that not all good products are the ones left on the shelf. Take the Betamax vs VHS video battle in the 80's. it was who held the rights to the films that won, not the better product.
Sleave valves are interesting to me but I have chosen my platform and hink that, for other reasons I will reveal in time to come that tack on to the whole project, it has to be the RVH (rotary Valve Head) that I must follow. As good as SLeeve Valves are, they wont work with our next technology.

[xxChrisxx]

I wish you the greatest of luck rotaryvalveman.
I just thought I should again mention that 'sleeve valve' engines were fully proven in the 1940's and were in reliable service on military operations through out WW2 in both fighters and bombers.

They were proven, but as fuels technology increased so that any advantsge of a sleeve valve dissapeared. Even Sir harry Ricardo had to concede this point (probably the biggest sleeve valve advocate ever)

However, now we've reached the point where the reciprocating poppet valves are reaching their limit it certainly is time to look at sleeve valves again. If rotaryvalveman really has come up with a novel solution to the sealing problem then it's really interesting. (I really wan't to know what it is!)

If you equate efficiency with power output per liter. These sleeve valve engines produced nearly three times the power of even four valve per cylinder poppet valved engines and later non operational developments with supercharged stratified charged two stroke sleeve valce engines, resulted in documented results close to five thousand horsepower from 26 liters.

I'm very sorry, but you just can't compare engines like this. It's better to use BMEP to find out how they compare. The power gain is more than likely becuse it wa a two stroke.

1938 Spec (the 1200hp version) Merlin (single stage supercharged)
BMEP: Power W * Revolutions per cycle / Displaced Volume m^3 * Rev/s

876000 * 2 / 0.027 * 47.5 = 1 366 081 Pa

Rolls Royce Crecy (using wikipedia values) Supercharged to 2 bar and turbocharged..
2035000 * 1 / 0.026 * 41.66 = 1 878 762 Pa

Cercy was was 37% better it terms of output potential. This is more than likely due to the 2 stroke arrangement with the valves having a minimal effect. As 2 strokes don't use poppet valves anyway.

Modern F1 Engine Naturally Aspirated:
566000 * 2 / 0.0024 * 283 = 1 666 666 Pa.

Turbo F1 Era. Race spec engine. Boosted to 2.4 bar. Apprx 600 hp output.
447000 * 2 / 0.0015 * 166 = 3 590 361 Pa

1.8 20v T In the Audi TT. output 220Hp at about 5500 rpm.
164000 * 2 / 0.0018 * 91 = 2 002 442 Pa

So as a comparison: A modern naturally aspirated F1 engine puts out 16.6 Bar BMEP.
A 2 stroke twincharged Crecy puts out 18.8 Bar BMEP. The turbo era F1 engines were putting out approx 36 Bar BMEP. Even a modern turbocharged road engine gets a higher BMEP figure to the Crecy.

This is very little ultimate performace difference, considering it's a 2 stoke AND boosted. To give typical road figures: Na road engines get about 8-12 BAr and boosted engines get 11-17.

This technology works, is reliable and was prevented from on going development in road and race vehicles because of cost and the politics that you find so detrimental to your rotary work.
Current ic engines in road and race vehicles IMO are many decades obsolete even by 1940's standards. It is one of the worst cases of deluding the public for profit in this and the last century.

You site lots of old engines, but they are so different from each other that it makes a comparison meaningless (unless you use a non dimensional method like the BMEP). Becuase the Crecy made more power, you cannot simply attribute that to the valve arrangement. For a direct comparison to see what difference the vavles make, you need to compare and identical engine. 1 running poppets the other running sleeves.

[rotaryvalveman]

And that is exactly what I intend to do. Pick the very best (or somewhere near it) single cylinder, then four cylinder and then (if I can get one) an F1 engine and do exactly that. Improve all areas from the three important envelopes of power, real world performance and reliability as well as emmision levels and bea them on a like for like basis in such a way as is financaily viable in that it will be a retrofittable head ither aftermarket or stopping the production line and starting it again.
take the present status quo and shake it up a little. Long live the internal combustion engine.

Oh, for the record I have a pathological hatered for the electric car. The Hybrid I am fine with as long as we have chemical protable power and we can make it clean and sustainable but please, no silent soulless devil's workshop satanic battery cars.

But for now, basic engineering in getting a simple idea to work simply is the goal.

[autogyro]

Simple comparisons exist between sleeve and poppet engines.
The American poppet valve radial engines of WW2 were half as powerful as the Bristol sleeve valve radial engines of the period.
That is why American bombers carried such a tiny bomb load.

The Crecy was not turbo charged but had a turbo generator so this energy also has to be added.
The Crecy also produced 33 percent of the aircrafts thrust solely from its exhaust, which also has to be added.

[xxChrisxx]

Simple comparisons exist between sleeve and poppet engines.
The American poppet valve radial engines of WW2 were half as powerful as the Bristol sleeve valve radial engines of the period.
That is why American bombers carried such a tiny bomb load.

The Crecy was not turbo charged but had a turbo generator so this energy also has to be added.
The Crecy also produced 33 percent of the aircrafts thrust solely from its exhaust, which also has to be added.

Ah so it's an energy recovery thing, I didn't read the entire article. It's still boosted by a supercharger. And you can't take into account thust from exhaust unless you are specifically using it in an aircraft role. Unless you stick a low bypass turbine after the first for more energy recovery.

But you've sort of skirted around the point that comparing directly two engine types of very VERY different design concepts is ultimately pointless. With so many variables different you cannot attribute what gains and what losses are invloved.

Rotaryvalveman seems to have this pont nailed, building a single cylinder of each and then testing. I actually remember seeing an SAE paper on just this subject. Unfortunately I no longer have my uni access to papers online.

[rotaryvalveman]

OK, in comparing like for like, I have seen a comparison between two identical motorcycles from 1936, one converted by R C Cross on a HRD but that was in 1936. Latterly, I have seent the article on the Gabelish (Sydney Australia) on two Yamaha XT500s ridden for a fair few hundred Kiliometers and in this comparison, they sttod up well to scrutiny.
Also, the Bishop stood up to the rigours of Ilmore's F1 programme.

I must confess to not really looking at sleeve valves as, forgive me if I am wrong, they still have a recipricating action which I wanted to get away from. I hope that my ignorance is not misplaced and that there is not something I have missed but I suppose it was just that my secondry interest only seems to fit with the rotary valve concept. Maybe I should take a little distraction and do some research but as I have left port already, changing ship now might be unwise.

[rotaryvalveman]

xxchrissxx

is the SAE paper you refer to headed titled, "Rotary Valves for Small Four-Cycle IC Engines", paper number 891793. If so it is sitting on my desk in front of me and was written for the 1989 small engine technology conference in Milwaukee, Wisconsin. If you like I could scan it and send it to you for your review.

[autogyro]

I cannot agree Chris when you say that comparisons cannot be made between engines of very different design concepts.
The Crecy sleeve valve engine was the ultimate aero piston engine.
If you read the article you will see that v twin test engines were used in development and direct comparisons were made.
Practicaly all the aero engines have been adapted to road vehicle use, mainly for racing or landspeed record cars. A friend of mine had a Merlin powered RR car he drag raced.
I would love to work up a test program on the Crecy engine technology adapted to F1 and other use.
The sleeves did reciprocate on the Crecy rotaryvalveman but other sleeve valves just rotated.
In anycase the reciprocation need not be a problem achieving much higher revs, which is the direction development needs to take. I would run a program to produce a sleeve operated electromagneticaly. There are few problems with sleeves in regard to cylinder head design, unlike rotary valves and I know of no other design that compares to the 'proven' potential of the two stroke blown sleeve valved engine.

[rotaryvalveman]

autogyro. One of the advantages I am leaning on in the RV design is that in valve opening and closing, there is no acceleration or deceleration. This is not so much the physical aspect of moving and slowing a mass as more the timming aspect. By that I mean the actual flow rate you see on the graph, even if the flow rates at each peak point are the same and at each percentage point of opening, the fact that you are already moving at full speed is the real gain I dont want to loose. I would like to see some info on a sleeve valve design that does not loose this advantage.

[Carlos]

EDIT - Following post contains all pictures and artical on Ralph Watson's rotary valve.

[rotaryvalveman]

http://img38.imageshack.us/i/enginefj.j ... .jpg[/img][/url]

I hope I have the hang of this putting pictures in lark, let's see if this works.