The rotary valve needs to be sealed against the head. I've been thinking on this idea for a while now and I believe the best solution would be something similar to what is used on a typical camshaft in the form of sealing rings. They function basically the same as a piston ring with a small gap to allow for expansion with heat. My Audi A8 4.2 uses two such sealing rings on each of the 4 camshafts. They are used to control the oil pressure being sent to the camshaft phasers. I haven't watched your other video on this engine yet, but you could even use a double lip seal at the intake end of the rotary valve. I am unsure of the exhaust end of the valve due to the heat.
Hi Steve Alan 😃 You are talking about active seals. To compare my rudimentary model engines with a high developed Audi A8 4.2l V8 is hard 😅 But I love V8! Have you alreday seen my V8 with rotary valve? Look here th-cam.com/video/8DCZT216YVY/w-d-xo.html You have many problems with model engines that you don't have with real engines. Everything is super small and you have very limited manufacturing options in the home workshop. In this case, the rotary valve is 12mm in diameter and the whole motor weighs only 500g. I once planned to build an active seal as a counter-piston. But there's just not enough space... This engine doesn't even have an oil system. Everything is lubricated by the oil in the methanol which is 20%!
i spent years thinking over rotary valves, was always a diehard supporter... have my little RCV engine, love it... oh let us never part! then one day it struck me... a spring, when compressed, returns that energy. so the argument about valve trains robbing power due to springs... it falls flat. that compressed spring simply stored energy. then returns it. until theyre floating, at least. and thats the point when youre already about to wreck an engine... rotary? its just loss. always there. friction, and no ability to return any work performed in operation. of course, they dont suffer from float, or bounce, there is that aspect... i feel its better chasing "piston valves"... low parasitic loss and the added benefit of actually producing power from the combustion, much like an "opposed piston".... im not letting on how ive worked out to achieve the ideal motion required to get them to work though ;) how to dwell for ~1.5 crank rotations with a rapid port opening and closure, yet maintain an ideal combustion chamber volume... another thing i spent years thinking about, ever since coming across an article on the "beare head six stroke"... but never doing anything about... lol, all i tend to do is make scrap metal as i follow the wrong sequence when machining something... eventually you run out of material and yeah. that being said, you may continue :) you do some nice work... and gotta love that slight "crackle" they have, similar to a two stroke due to the way the ports open...
I'm just glad that it's running somehow 😅 It sounds like you love tuning! have you seen my tuning series for another engine? th-cam.com/video/9yXi55uBFgk/w-d-xo.html
hello daniel! i soo enjoy watching the process of you making engines and testing them! i want to build engines too, but i dont know what hardware should i have. can you tell me all the hardware (and software) should i have to build model engines like you do? (for example CNC machine if needed, a software to make a 3D model, a test bench, etc.) thank you!
Hi man 👋 I'm glad that I was able to inspire you and that you want to build something yourself. For me, model making means doing a lot of things myself with simple tools. I use Fusion 360 as CAD and have a conventional lathe (Optimum D320) and a conventional milling machine (Optimum BF30) with a CNC attachment. So no high-end and expensive machines. Everything else is home-made, like my test bench. In model making, the journey is the destination. How do I reach the goal? What I need to get there? What are my skills and what I' m able to do? There are no rules or a specialist literature. Everyone does it a little differently. That's also the beauty of model making. It's a huge play ground!
I had the same idea back in 1982 and I built a prototype out of wood, because I had no metal working tools. I tried to explain the concept to my wife, but she had no clue about engines and just laughed and called it "my rolling pin".
Maybe if you could put 2 Apex like graphite seals on the valve it would seal better and keep it lubricated but be able to replace them kind of like brushes on a DC motor then you could run two ball bearings on each end of the rotary shaft with seals and oil through the bearings so that it would have less friction and last longer
I was thinking the same thing. Also, maybe a 2-stroke like mix to aid in lubrication? It is a very interesting problem. This guy might just come up with something.
Hi probablysomeonesomewhere 😃 This is just a prototype engine. My first homemade rotary valves were all with 2 ball bearings at the end points. I had 2 big problems. The positional accuracy of the bearings had to be within 5µm in the cylinder head, which was almost impossible to manufacture with simple home equipment. The other problem was that the RS bearings generated a lot of friction, making the valve train hard tu turn. I then gave up the system with ball bearings and switched to plain bearings. To put it simply, my rotary valves are actually just long plain bearings with openings in it. I don't have any seals beause it's just an smiple model engine. However, there are variants with an active seal as a counter-piston. Your approach using graphite or a graphite-like coating (DLC) would be very interessing when using an active sealing!
@danielhunzinker3577 thank you, I see how getting a ball bearing with that tight of a tolerance would be a problem lol, guess I didn’t really think about that, but on the graphite note I feel like it would help seal the cylinder better so that it could have slightly more compression. I feel like the reason it runs so slowly something compression related means an expert in anything like this. I’ve been wanting to design something like this myself, but I have or anything to make that happen, but I love you videos keep up the awesome work on these engines and thank you for taking the time to read what I had to say
The driven pulley on the rotary valve stem, has to much mass. The oening for the rotaryvale in the cylinder head is to large in the cylinder head. Too much of the RV-opening is exposed. Is the RV tuneable while running engine to meet other timings on higher rpm, to match torque request under load?
Hi aidshusten240 😃 This is just a prototype engine. It was also not my aim to install such a large belt pulley. But with this type of rotary valve you have to achieve a 1:4 ratio to the crankshaft. If the prototype were to be converted into a usable motor, a gear drive would have to be made to counteract the inertia. The opening in the cylinder head is part of the timing. If you make them smaller, the timing will be shorter and if you make them wider, they will be longer. All the openings at the intake, exhaust, rotary valve and cylinder head are calculated to get a timing of 50°/90°/90°/50°. Of course you're right! If you were to change the width of the opening in the cylinder head with a kind of slider, you would have variable valve timing!
What a pity it didn't perform as wished. It's a shame because the idea was very simple and clever. Might be a phase problem? Did you get an answer why it's performing so badly? It's a great opportunity for learn 😊
Wieder mal ein super Projekt. Ich habe vermutet, dass diese Steuerung ein bisschen weniger Leistung bringt, aber so viel weniger, damit habe ich nicht gerechnet. Der Kurbelzapfen ist erschreckend blau geworden. Der Drehschieber hat auch Verfärbungen. Warum machst du auf dem Drehschieber nicht eine wellenförmige besser schraubenförmig (in die richtige Richtung)Schmiernute rein. Nur ca. 0.1-0.2mm tief und sehr schmal. Vielleicht mit einem spitzen Fräsen. Man könnte sogar 2 Nuten machen. Wirklich nur ganz fein mit der CNC Maschine. Hätte vielleicht einen ähnlichen Effekt wie eine Labyrinthdichtung. Vergleichbar mit den Schmiernuten am Kolbenhemd bei ringlosen RC Car Motoren. so würde vielleicht auch ein bisschen Schmieröl an die kritischen Stellen kommen ohne dass man das Spiel des Schiebers vergrössern muss.
Hi Argentum 😃 Freut mich wenn meine Bastelbude gut ankommt 😅 Ehrlich gesagt hatte ich auch mit etwas mehr Leistung gerechnet. Ich merkte aber schon beim 1.Anlassen, dass er nicht brillieren wird. Man merkt das schnell daran, wie die Gasannahme und das Hochdrehverhalten ist. Dein Gedanke ist sehr gut. Man könnte dies tatsächlich in den nicht funktionellen Stellen umsetzen um so eine Labyrinth Dichtung zu bekommen 🤔
@danielhunziker3577 Ob die Idee mit der Schmiernute funktioniert weiss ich nicht. Dichtkörper einzubauen finde ich zu aufwendig. Rein vom Gefühl her finde ich das Einlasfenster in den Zylinderkopf, sehr gross. Ich nehme an du hast die Strömungsgeschwindigkeit, wenn das Ventil geöffnet ist, bei Highspeed in etwa berechnet. Wieviel Öl gibst du ins Kurbelgehäuse und welches? Vermutlich war es ein bisschen zu wenig Öl.
I think i can see why it's weaker, there is mixture losses in the ports. When the exhaust port is open, exhaust gasses rush out and port is closed off but there is still lot of exhaust gasses in the valve port itself so when intake port opens you are sucking back that bit of exhaust gasses with the fresh charge and same thing happens on the exhaust side where you push bit if fresh charge that was stuck in the valve, out into the exhaust, maybe it would work better with two separate valves for intake and exhaust with 4 to 1 timing. This way they are still spinning lot slower, reducing fricton and heat.
It's difficult to say exactly where the problem is. What can be said is that the gas flow has a kind of resistance in the one valve. This results in a poor filling of the cylinder. I rather suspect that the gas flowing out is interfering with the gas flowing in, resulting in an alternating resistance. As higher the gasflow, as higher this resistance become. Don't worry, that was just a test engine here and my normal eotary valve heads have 2 valves.
The problem with rotary valve engines is you can't extend valve timing aka hold the valves open for longer without affecting the idle and starting procedure, good engine for running at a specific RPM but I don't know how you go about opening a rotary valve wider...
Sure you could, the rotary valve could have a secondary cylinder inside of it that actuated much like a typical cam phaser. It would have a corresponding port that at full open would match the actual port but could be turned to shrink the port. So, at lower speeds and idle where less air would be required the port could be smaller and a smaller opening means less time open. Obviously the opposite would occur at higher RPM's or heavier load situations and the port would be fully open thus longer intake duration.
Hi avocadoarms358 😃The timing of a rotary valve must indeed be treated somewhat differently to that of a poppet valve, as the valve cross-sectional area behaves differently when opening/closing. But basically the same laws apply as for poppet valves. If you have aggressive timings, the engines runs less good in the lower speed range and the idle speed is higher.
The spark from the exhaust is something we had seen on our Briggs and Stratton rotary valve engines as well. I suspect you may be correct on the Spark's origin. The performance does appear low on your current engine, how does the valve timing and cross sectional area for air flow compare to your other designs?
Hi John 😃 Nice to hear from you! The problem with sparks out of the exhaust and material detachment is a new phenomenon for me. My previous engines didn't have that. I think that this also has to do with the choice of material for the rotary valve. I used Invar steel for this motor here. That may not have been the best choice. It tends to cold-weld, especially when the lubricating film breaks off. I suspect that it happened at small spots, the material was torn out at this spot (with the rotary energy of the rotary valva) and was ejected through the exhaust. But I won't be following the 1 valve concept either way. I'm currently working on a new version of a rotary valve head with a coated rotary valve (low friction, hard and longlife coating). The valve cross-section of the single valve is identical to one valve from my 2 valve design. However, I suspect that the problem lies more in the interaction of the gas flow in the single valve. The gas flowing out blocks the gas flowing in and vice versa. This indirectly leads to a reduced timing and therefore lower performance. But these are just assumptions. But I can proudly say that I have tried it out and learned something 😊 How are your projects going? Any new ideas for a improved rotary valve engine?
@@danielhunziker3577 We have usually made our calves out of high lead steal for easy machining and lubricity. In addition it is running against a nice soft leaded bronze seal. That said, it gets all scratched up, however carbon then builds up in the scratches helping it seal. We haven't done anything lately with the rotary valve other than run it occasionally. I know I need to work on the timing side of the valve train. The one disadvantage of starting with a fuel injected engine is it is much more challenging to know everything is setup correctly compared to an engine with points and a carb.
@@johnpearson492 The rotary valve material was an experiment here. As you, I use standardizes a high leaded bronze for the rotary valve and a cast iron sleeve (CuSn7Zn4Pb7-C / EN-GJL-250). This is a common material pairing for plain bearings. This combnation works very well for rotary valve as well. I would like to start another experiment with DLC coated brass rotary valve which run directly in ENAC 48000 aluminum. I can understand that. There are so many more possible sources of error and setting options. Have you had it on the dyno in the meantime to get an impression of its performance?
Hi lowa599 😃 I don0t think that the timing is the problem. It's already very "sharp" with 50°/90°/90°/50°. I suspect the problem lies more in the interaction of the flow in the individual valve. The outflowing gas obstructs the inflowing gas and vice versa. This indirectly leads to reduced timing and thus to lower performance.
I don't think a rotary valve could provide more flow than a port, in any reasonable form. Also, by running a rotary valve, you eliminated the factory supercharger, the one under the piston...that is definitely hurting flow! (technically not a charger, but the piston going down forces the air to go from the crankcase to the combustion chamber)
i just remembered something to prove that, the Detroit Diesel 2-stroke v-block. It didn't have the crankcase to pressurize the intake, so it had a roots-type supercharger on all models, plus a turbocharger on some models.
6:22 that deceleration sounds so good, specially the belt whine
Thanks man! The sound of this engine overall is very good. The performance isn't...
The rotary valve needs to be sealed against the head. I've been thinking on this idea for a while now and I believe the best solution would be something similar to what is used on a typical camshaft in the form of sealing rings. They function basically the same as a piston ring with a small gap to allow for expansion with heat. My Audi A8 4.2 uses two such sealing rings on each of the 4 camshafts. They are used to control the oil pressure being sent to the camshaft phasers. I haven't watched your other video on this engine yet, but you could even use a double lip seal at the intake end of the rotary valve. I am unsure of the exhaust end of the valve due to the heat.
Hi Steve Alan 😃 You are talking about active seals. To compare my rudimentary model engines with a high developed Audi A8 4.2l V8 is hard 😅 But I love V8! Have you alreday seen my V8 with rotary valve? Look here th-cam.com/video/8DCZT216YVY/w-d-xo.html You have many problems with model engines that you don't have with real engines. Everything is super small and you have very limited manufacturing options in the home workshop. In this case, the rotary valve is 12mm in diameter and the whole motor weighs only 500g. I once planned to build an active seal as a counter-piston. But there's just not enough space... This engine doesn't even have an oil system. Everything is lubricated by the oil in the methanol which is 20%!
@@danielhunziker3577 I had not until just now! I am beyond impressed! I'll be keeping up with all your updates!!!!
i spent years thinking over rotary valves, was always a diehard supporter... have my little RCV engine, love it... oh let us never part!
then one day it struck me...
a spring, when compressed, returns that energy.
so the argument about valve trains robbing power due to springs... it falls flat. that compressed spring simply stored energy. then returns it. until theyre floating, at least. and thats the point when youre already about to wreck an engine...
rotary? its just loss. always there. friction, and no ability to return any work performed in operation. of course, they dont suffer from float, or bounce, there is that aspect...
i feel its better chasing "piston valves"... low parasitic loss and the added benefit of actually producing power from the combustion, much like an "opposed piston".... im not letting on how ive worked out to achieve the ideal motion required to get them to work though ;) how to dwell for ~1.5 crank rotations with a rapid port opening and closure, yet maintain an ideal combustion chamber volume...
another thing i spent years thinking about, ever since coming across an article on the "beare head six stroke"... but never doing anything about... lol, all i tend to do is make scrap metal as i follow the wrong sequence when machining something... eventually you run out of material and yeah.
that being said, you may continue :) you do some nice work... and gotta love that slight "crackle" they have, similar to a two stroke due to the way the ports open...
Simply beautiful. Great work sir
Thanks man!
You should add a tuned exhaust pipe to this amazing engine
I'm just glad that it's running somehow 😅 It sounds like you love tuning! have you seen my tuning series for another engine? th-cam.com/video/9yXi55uBFgk/w-d-xo.html
hello daniel!
i soo enjoy watching the process of you making engines and testing them!
i want to build engines too, but i dont know what hardware should i have.
can you tell me all the hardware (and software) should i have to build model engines like you do? (for example CNC machine if needed, a software to make a 3D model, a test bench, etc.)
thank you!
Hi man 👋 I'm glad that I was able to inspire you and that you want to build something yourself. For me, model making means doing a lot of things myself with simple tools. I use Fusion 360 as CAD and have a conventional lathe (Optimum D320) and a conventional milling machine (Optimum BF30) with a CNC attachment. So no high-end and expensive machines. Everything else is home-made, like my test bench. In model making, the journey is the destination. How do I reach the goal? What I need to get there? What are my skills and what I' m able to do? There are no rules or a specialist literature. Everyone does it a little differently. That's also the beauty of model making. It's a huge play ground!
@@danielhunziker3577your reply means a lot to me! thank you so much, and im looking forward to all of it :)
I had the same idea back in 1982 and I built a prototype out of wood, because I had no metal working tools. I tried to explain the concept to my wife, but she had no clue about engines and just laughed and called it "my rolling pin".
Maybe if you could put 2 Apex like graphite seals on the valve it would seal better and keep it lubricated but be able to replace them kind of like brushes on a DC motor then you could run two ball bearings on each end of the rotary shaft with seals and oil through the bearings so that it would have less friction and last longer
I was thinking the same thing. Also, maybe a 2-stroke like mix to aid in lubrication? It is a very interesting problem. This guy might just come up with something.
Hi probablysomeonesomewhere 😃 This is just a prototype engine. My first homemade rotary valves were all with 2 ball bearings at the end points. I had 2 big problems. The positional accuracy of the bearings had to be within 5µm in the cylinder head, which was almost impossible to manufacture with simple home equipment. The other problem was that the RS bearings generated a lot of friction, making the valve train hard tu turn. I then gave up the system with ball bearings and switched to plain bearings. To put it simply, my rotary valves are actually just long plain bearings with openings in it. I don't have any seals beause it's just an smiple model engine. However, there are variants with an active seal as a counter-piston. Your approach using graphite or a graphite-like coating (DLC) would be very interessing when using an active sealing!
@danielhunzinker3577 thank you, I see how getting a ball bearing with that tight of a tolerance would be a problem lol, guess I didn’t really think about that, but on the graphite note I feel like it would help seal the cylinder better so that it could have slightly more compression. I feel like the reason it runs so slowly something compression related means an expert in anything like this. I’ve been wanting to design something like this myself, but I have or anything to make that happen, but I love you videos keep up the awesome work on these engines and thank you for taking the time to read what I had to say
@@rafaellastracom6411 well we got an answer
The driven pulley on the rotary valve stem, has to much mass. The oening for the rotaryvale in the cylinder head is to large in the cylinder head. Too much of the RV-opening is exposed.
Is the RV tuneable while running engine to meet other timings on higher rpm, to match torque request under load?
Hi aidshusten240 😃 This is just a prototype engine. It was also not my aim to install such a large belt pulley. But with this type of rotary valve you have to achieve a 1:4 ratio to the crankshaft. If the prototype were to be converted into a usable motor, a gear drive would have to be made to counteract the inertia. The opening in the cylinder head is part of the timing. If you make them smaller, the timing will be shorter and if you make them wider, they will be longer. All the openings at the intake, exhaust, rotary valve and cylinder head are calculated to get a timing of 50°/90°/90°/50°. Of course you're right! If you were to change the width of the opening in the cylinder head with a kind of slider, you would have variable valve timing!
What a pity it didn't perform as wished. It's a shame because the idea was very simple and clever. Might be a phase problem? Did you get an answer why it's performing so badly? It's a great opportunity for learn 😊
Wieder mal ein super Projekt. Ich habe vermutet, dass diese Steuerung ein bisschen weniger Leistung bringt, aber so viel weniger, damit habe ich nicht gerechnet. Der Kurbelzapfen ist erschreckend blau geworden. Der Drehschieber hat auch Verfärbungen. Warum machst du auf dem Drehschieber nicht eine wellenförmige besser schraubenförmig (in die richtige Richtung)Schmiernute rein. Nur ca. 0.1-0.2mm tief und sehr schmal. Vielleicht mit einem spitzen Fräsen. Man könnte sogar 2 Nuten machen. Wirklich nur ganz fein mit der CNC Maschine. Hätte vielleicht einen ähnlichen Effekt wie eine Labyrinthdichtung. Vergleichbar mit den Schmiernuten am Kolbenhemd bei ringlosen RC Car Motoren. so würde vielleicht auch ein bisschen Schmieröl an die kritischen Stellen kommen ohne dass man das Spiel des Schiebers vergrössern muss.
Hi Argentum 😃 Freut mich wenn meine Bastelbude gut ankommt 😅 Ehrlich gesagt hatte ich auch mit etwas mehr Leistung gerechnet. Ich merkte aber schon beim 1.Anlassen, dass er nicht brillieren wird. Man merkt das schnell daran, wie die Gasannahme und das Hochdrehverhalten ist. Dein Gedanke ist sehr gut. Man könnte dies tatsächlich in den nicht funktionellen Stellen umsetzen um so eine Labyrinth Dichtung zu bekommen 🤔
@danielhunziker3577
Ob die Idee mit der Schmiernute funktioniert weiss ich nicht. Dichtkörper einzubauen finde ich zu aufwendig. Rein vom Gefühl her finde ich das Einlasfenster in den Zylinderkopf, sehr gross. Ich nehme an du hast die Strömungsgeschwindigkeit, wenn das Ventil geöffnet ist, bei Highspeed in etwa berechnet. Wieviel Öl gibst du ins Kurbelgehäuse und welches? Vermutlich war es ein bisschen zu wenig Öl.
I think i can see why it's weaker, there is mixture losses in the ports. When the exhaust port is open, exhaust gasses rush out and port is closed off but there is still lot of exhaust gasses in the valve port itself so when intake port opens you are sucking back that bit of exhaust gasses with the fresh charge and same thing happens on the exhaust side where you push bit if fresh charge that was stuck in the valve, out into the exhaust, maybe it would work better with two separate valves for intake and exhaust with 4 to 1 timing. This way they are still spinning lot slower, reducing fricton and heat.
It's difficult to say exactly where the problem is. What can be said is that the gas flow has a kind of resistance in the one valve. This results in a poor filling of the cylinder. I rather suspect that the gas flowing out is interfering with the gas flowing in, resulting in an alternating resistance. As higher the gasflow, as higher this resistance become. Don't worry, that was just a test engine here and my normal eotary valve heads have 2 valves.
The problem with rotary valve engines is you can't extend valve timing aka hold the valves open for longer without affecting the idle and starting procedure, good engine for running at a specific RPM but I don't know how you go about opening a rotary valve wider...
that goes for a traditional camshaft aswell
Sure you could, the rotary valve could have a secondary cylinder inside of it that actuated much like a typical cam phaser. It would have a corresponding port that at full open would match the actual port but could be turned to shrink the port. So, at lower speeds and idle where less air would be required the port could be smaller and a smaller opening means less time open. Obviously the opposite would occur at higher RPM's or heavier load situations and the port would be fully open thus longer intake duration.
Hi avocadoarms358 😃The timing of a rotary valve must indeed be treated somewhat differently to that of a poppet valve, as the valve cross-sectional area behaves differently when opening/closing. But basically the same laws apply as for poppet valves. If you have aggressive timings, the engines runs less good in the lower speed range and the idle speed is higher.
@danielhunziker3577 so you are able to extend timing?
Sounds like it might be over-ported for your desired RPM. There was a noticeable increase in high RPM torque, just before you let off the throttle.
The spark from the exhaust is something we had seen on our Briggs and Stratton rotary valve engines as well. I suspect you may be correct on the Spark's origin.
The performance does appear low on your current engine, how does the valve timing and cross sectional area for air flow compare to your other designs?
Hi John 😃 Nice to hear from you! The problem with sparks out of the exhaust and material detachment is a new phenomenon for me. My previous engines didn't have that. I think that this also has to do with the choice of material for the rotary valve. I used Invar steel for this motor here. That may not have been the best choice. It tends to cold-weld, especially when the lubricating film breaks off. I suspect that it happened at small spots, the material was torn out at this spot (with the rotary energy of the rotary valva) and was ejected through the exhaust. But I won't be following the 1 valve concept either way. I'm currently working on a new version of a rotary valve head with a coated rotary valve (low friction, hard and longlife coating). The valve cross-section of the single valve is identical to one valve from my 2 valve design. However, I suspect that the problem lies more in the interaction of the gas flow in the single valve. The gas flowing out blocks the gas flowing in and vice versa. This indirectly leads to a reduced timing and therefore lower performance. But these are just assumptions. But I can proudly say that I have tried it out and learned something 😊 How are your projects going? Any new ideas for a improved rotary valve engine?
@@danielhunziker3577 We have usually made our calves out of high lead steal for easy machining and lubricity. In addition it is running against a nice soft leaded bronze seal. That said, it gets all scratched up, however carbon then builds up in the scratches helping it seal.
We haven't done anything lately with the rotary valve other than run it occasionally. I know I need to work on the timing side of the valve train. The one disadvantage of starting with a fuel injected engine is it is much more challenging to know everything is setup correctly compared to an engine with points and a carb.
@@johnpearson492 The rotary valve material was an experiment here. As you, I use standardizes a high leaded bronze for the rotary valve and a cast iron sleeve (CuSn7Zn4Pb7-C / EN-GJL-250). This is a common material pairing for plain bearings. This combnation works very well for rotary valve as well. I would like to start another experiment with DLC coated brass rotary valve which run directly in ENAC 48000 aluminum.
I can understand that. There are so many more possible sources of error and setting options. Have you had it on the dyno in the meantime to get an impression of its performance?
👏🏻👏🏻👏🏻👏🏻👏🏻
the rotary valve needs to open quicker.
look at sleeve valve engines.
Hi lowa599 😃 I don0t think that the timing is the problem. It's already very "sharp" with 50°/90°/90°/50°. I suspect the problem lies more in the interaction of the flow in the individual valve. The outflowing gas obstructs the inflowing gas and vice versa. This indirectly leads to reduced timing and thus to lower performance.
@@danielhunziker3577That's what a tuned pipe is for.
I don't think a rotary valve could provide more flow than a port, in any reasonable form.
Also, by running a rotary valve, you eliminated the factory supercharger, the one under the piston...that is definitely hurting flow!
(technically not a charger, but the piston going down forces the air to go from the crankcase to the combustion chamber)
i just remembered something to prove that, the Detroit Diesel 2-stroke v-block. It didn't have the crankcase to pressurize the intake, so it had a roots-type supercharger on all models, plus a turbocharger on some models.