I appreciate your design, an automatic, "unsticking" mechanism essentially. My brother and I have put a lot of effort in to rotary valve engines and had much success with the, floating seal concept where combustion pressure pushes the seal against a fixed rotating cylindrical valve. Check out the MrPizzaman09 youtube channel. We have occasionally had seizing issues but they have related primarily to overheating events with no issue if sufficient coolant or airflow is kept over the head. It would appear that your design copes with thermal expansion quite readily. What is the assumption of the coefficient of friction on the helix? I feel like it may be a very sensitive factor in this design. The lower the helix angle the less sensitive it may be. You are absolutely correct in assuming that exhaust pressure and intake vacuum will drive the valve towards the intake, I've had press fit bearings driven right out of housings due to this. Keep it up! I love to see others working with rotary valves. So many unique ways to accomplish the same task.
Thanks guys, I watched your videos and take my hat of to you both. This work is 100 years too late but still enjoyable. It would be nice to put one on a single cylinder motorcycle. I built a variation of the one shown here and will put a video up when it runs, 17:1 means I will have to cook up a more robust ignition system than the stock gx200 one which is why it isn't running yet, has great compression. All the best with your endeavors.
The taper angle will be critical so it doesn't stick like a taper shaft tool holder. Your angle might be okay, but it might need to be steeper. I'm also wondering how well it will seal under peak combustion pressures versus the floating seal design. This is certainly an improvement over a straight design. A high ratio helix that really forces the tube to the right when the friction goes up might work, though it's a rather dynamic system to simulate or estimate what will happen in real life. We made a 16:1 CR rotary valve and it didn't blow out the dual spark plugs, but it was running on 100 octane isooctane.
This idea was first posited in the Abingdon cross engine developed at the Shell Research Centre, Abingdon, UK in the late 1960's or early 1970's. This concept is old and well established.
that may be true, the only book i read on the subject was Hunter, rotary valve engines which was in the mid 40s. can you share any article of information and which aspect are you saying is not novel?
@@vtzerosix The cylindrical nature of the valve, with ports and internal oblique divider. Its position in the head. The floating head with a fulcrum which allows the clamping pressure to fluctuate proportionate to the cylinder pressure so that the clamping pressure is always just sufficient for obfuscation. All covered in an article in Motor magazine in early 70s. I read it in an archive in the Cambridge University Engineering Department library in my Masters' degree course.
This is a great design. It would be good to see a prototype. BTW, john doe, he-he. I use "Joe Doe" for my google mail. I had many sales people coming to my door and calling me by my first and last name. I asked, where did yo get my name: well your name is in public domain by Google. No more salesman at the door since I changed it. Google is constantly stealing your personal information.
the seal won't last. you suggested leaded bronze, but the top of the cylinder will get too hot for lead. Oil will work, but then also get burned. engines with overhead poppet valves & no head gasket (cylinder & head are one piece) were built in the past & are now.
Exhaust heat is the killer for these designs, and taken even higher by the increase in power and RPMs with the better breathing.rotary valves can offer. The sleeve valve engine was perhaps the better design.
Very true. I don't look at rotary valve engines as something that will ever catch on, but as something that is just mechanically interesting. It's a logically valve train that has some seriously tough engineering issues to solve to make it a design that can run for a reasonable amount of time without intervention. This design helps solve one of the difficult problems.
yes and no, I am playing with a variant of this on a 200cc honda engine. I will make a video if it runs. its on the bench, i have compression at 17:1 but its blowing the spark out as its a magneto system.
I like this concept, elegant and thoughtful design, particularly the way you work the 100% , 75% intake exhaust area ratio into the conical sealing mechanism and stronger exhaust side of the rotor, modern materials science between rotor and seal is probably the only suggestion I could make. Enjoy your work and ignore the naysayers, they've probably never had an original idea in their life. Regards, Brian Smith US6237556
