Wasn't there a car in the 20's that had a similar valve system?
What's the exhaust look like does the factory header bolt up? From the video it sounds loud is there any header at all? Would love to see a driving video and definitely a dyno! This is a super cool project. Anything patented or is it patentable or based on previous stuff?
J1000 said:What's the exhaust look like does the factory header bolt up? From the video it sounds loud is there any header at all? Would love to see a driving video and definitely a dyno! This is a super cool project. Anything patented or is it patentable or based on previous stuff?
The factory header bolts up. I spent a couple days grinding it out to make it larger and smoother, as well as flow better with the mating geometry.
I have run it without the exhaust hooked up past the collector and it is pretty awesome... there should be a video on my channel with it like that.
In terms of patentable, I looked at a few things, but they all seem to be patented 10-50 years ago. I have one feature that's different, but not worth patenting. Also, if I get a patent and have to spend $10-$100k, then am I going into production to make money??? Probably not.
This website was quite inspirational for all of my rotary valve projects. I cam up with the general idea before finding this website or knowing what the official name was (axial flow rotary valve engine). I highly encourage people to read it since it's very good.
http://ralphwatson.scienceontheweb.net/rotary.html
I read the article you included in your post, and seems most of those examples used rotary valves on intake and exhaust ports, was there a particular reason or benefit to just doing it on the intake side?
Chesterfield said:I read the article you included in your post, and seems most of those examples used rotary valves on intake and exhaust ports, was there a particular reason or benefit to just doing it on the intake side?
This uses a rotary valve for both intake and exhaust.
Intake gas comes in one end of the tube, when the tube rotates enough that the port lines up, intake gas is pulled in to the cylinder.
The tube rotates closed, compression and combustion occur.
The tube rotates open to the exhaust port and then the exhaust gas flows down the OTHER end of the tube.
The tube rotates more and then the intake port is lined up and we start all over again.
What I want to know is do you have any cooling on the rotary valve so that the hot exhaust gasses aren't warming up the intake charge too badly.
the_machina said:Chesterfield said:I read the article you included in your post, and seems most of those examples used rotary valves on intake and exhaust ports, was there a particular reason or benefit to just doing it on the intake side?
This uses a rotary valve for both intake and exhaust.
Intake gas comes in one end of the tube, when the tube rotates enough that the port lines up, intake gas is pulled in to the cylinder.
The tube rotates closed, compression and combustion occur.
The tube rotates open to the exhaust port and then the exhaust gas flows down the OTHER end of the tube.
The tube rotates more and then the intake port is lined up and we start all over again.
What I want to know is do you have any cooling on the rotary valve so that the hot exhaust gasses aren't warming up the intake charge too badly.
Thanks for the clarification, I must have been too busy looking at the intake side to notice. Plus when I read he the factory header bolted up, my brain went 2+2=5 means factory exhaust valve in the head. Maybe I needed more caffeine this morning before trying to contemplate axial flow rotary valved engines. Thanks again.
"What I want to know is do you have any cooling on the rotary valve so that the hot exhaust gasses aren't warming up the intake charge too badly. "
No, not directly in the valve like the Ralph Watson design. The floating seal on the bottom has cooling running around it and the cylinder head has cooling channels. The exhaust seal holder has coolant running through it as well, which is sandwiched between the exhaust bearings (yes, it has muffler bearings...) and the exhaust manifolds.
In reply to Ransom :
I've gotta know, does the system maintain good cylinder compression? Is it designed such that the compression ratio is the same as factory? Have you done a compression test? It seems like you'd have to do a lot of work to maintain compression between the valve housing and the cylinder, and also between the rotating valve and the chamber. Are the shaft seals positioned to assist in the cylinder compression or is it just the fit between the valve and valve housing? Neat!
DDT said:In reply to Ransom :
I've gotta know, does the system maintain good cylinder compression? Is it designed such that the compression ratio is the same as factory? Have you done a compression test? It seems like you'd have to do a lot of work to maintain compression between the valve housing and the cylinder, and also between the rotating valve and the chamber. Are the shaft seals positioned to assist in the cylinder compression or is it just the fit between the valve and valve housing? Neat!
Yes, it holds compression quite well around the rotary valves. The stock compression ratio was 10.2:1 and we designed it to be 10:1, which was largely driven by the tradeoff of port opening angles and volume of the combustion chamber. With the right timing, you can achieve 165 psi of compression using the starter motor, but the valve timing that achieves this is really terrible for higher end power (the car will max out at 3,000 rpm). As for the challenges for sealing the valve, there are a lot of considerations when you make the port and valve hole sizes. And when we made the floating seals, we effectively lapped the seals to the right size. The rotary shaft seals on either end of the valve only seal the intake vacuum pressure or the exhaust pressure.... they aren't going to seal against a few hundred or even 1000+ psi. The seals seem to be holding up better than I was expecting and the only issues have mainly been due to damage during installation. The durability of the valves and floating seals has been better than I was expecting as well, which I think is largely due to our design have relatively low unit pressure on the mating surfaces due to the geometry. I think a lot of people have issues with their own rotary valve engines because they try and make the seal super tiny... we have taken more of the old equipment design approach. We also didn't skimp on any of the material choices for the valves, head or floating seals....
Last night we tested out the cooling system with the new expansion tank cap and 15psi pressure relief valve. I was able to have the temp. gauge read 104C with no boiling in the cylinder head! It used to boil at ~96C. We drove it pretty hard and ran it for almost a half hour without any issues. Next job is to route the output of the breather back into the oil pan...as my 15L Cummins breather was really doing a good job at dumping it all on the ground
Very cool stuff!
It reminds me: I came across this article about a prototype rotary valve engine a few years ago, which I thought some of you might be interested in.
In reply to taylorp035 :
Really cool, I can see the approach through the forum window. Conventional means done right. I wouldn't have guessed that much compression, that's better than most of my hot rods! Reading between the lines, it sounds like you might have to put V-tec on the drive system sometime around year 3. It seems to be quite sensitive to timing.
omg wut.
Positively wild stuff. Good grief. I applaud (bow to?) the effort, but hole guacamole, talk about effort/hp!
damen
gencollon said:Very cool stuff!
It reminds me: I came across this article about a prototype rotary valve engine a few years ago, which I thought some of you might be interested in.
This is another good article showing some of the benefits of an axial flow rotary valve engine. I can't wait for someone to pull this prototype engine/car our of a shed some day and show it to the world. Supposedly they made it run, but the officials banned this type of design about a month before they got it running. I believe it made about 10% more power than the best poppet valve F1 engine of the era.
Video update!!!
Added 6 new spark plugs and now it magically fires on all of the cylinders! Perfectly smooth and way more power. This should help for the dyno run.
We chased down a plethora of coolant and oil leaks, so that should make things a bit more tolerable where ever it drives.
Side note, I've confirmed my listing of my enthusiast special 1988 Jeep Comanche on BringATrailer! They claim the ad will be ready in about 2 weeks.
Rare combo of the base trim level, 4.0L Inline 6, 5 speed manual, 4 wheel drive and the short bed. Hopefully it does well! Drove it all the way from California to Pennsylvania.
Very cool.
I'm wondering what problems the patent holders from 50 years ago ran into and how/if you plan to solve those problems.
Dyno Videos!
106 HP and 127 ft*lbs of torque.
The blue lines are the original torque and hp curves. Red and Blue were two runs we did yesterday.
We definitely had a software tuning issue, since the engine would fall flat on it's face at 5,500 rpm. Earlier in the day, it was 4,500 rpm and that value kept increasing as we added more spark. Since we are using the OEM ECU, we believe there are about 100 other tables that were affecting our base spark and fuel tables that we still need to figure out. For sure, we need to deal with the variable valve timing that the car still thinks it has in the software. We are also going to figure out how to log data while it's running so we stand a better chance at figuring things out.
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