Dan Gurney's just patented an engine that basically has counter-rotating pistons:
http://www.thetruthaboutcars.com/2015/09/dan-gurney-patents-new-moment-cancelling-engine/
How is this meaningfully different than the MotoCzysz Z-line 4?
http://motoczysz.com/news/article/introducing_motoczysz_z-line_4_engine
He's turned the cranks 90 degrees, and it looks like expanding the Gurney engine to a four banger would end up with a square arrangement instead of inline.
The Michael Czysz story is nothing short of a tragedy...I don't know if development of his patents is continuing anywhere, but hopefully SOMEONE ends up doing cool things with this tech.
Turns out there are earlier counter-rotating shaft engines:
https://en.wikipedia.org/wiki/Suzuki_RG500
http://www.motorcyclenews.com/sixty-for-sixty/2015/march/60-greatest-bikes-ariel-square-4-mk2/
RossD
PowerDork
9/3/15 9:13 a.m.
In reply to SlickDizzy:
He did that engine so it didn't have gyroscopic forces on the bike and rider, right? Or was there something else going on.
I remember watch some documentary about him and his bike but know I can't remember much about it...
In reply to RossD:
He was diagnosed with terminal cancer shortly after the MotoGP class rules changed and his bike was deemed ineligible. "Insult to injury" would be the understatement of the century.
MadScientistMatt wrote:
He's turned the cranks 90 degrees, and it looks like expanding the Gurney engine to a four banger would end up with a square arrangement instead of inline.
a "square 4" engine sounds intriguing
The boss has a Suzuki RG500. It's not just a square four, it's a two stroke with an exhaust pipe for each cylinder. You can tell if one cylinder is running poorly by watching the smoke out of the exhaust Apparently it's really fun to ride, small and nimble instead of big and powerful.
In the 14 years I've worked here, I've seen it reassembled after a rebuild, ridden on the road once and then it extruded a piston through the carb on the first session of the first track day. Now it's back where it was when I moved here...
NOHOME
UberDork
9/3/15 9:57 a.m.
Keith Tanner wrote:
The boss has a Suzuki RG500. It's not just a square four, it's a two stroke with an exhaust pipe for each cylinder. You can tell if one cylinder is running poorly by watching the smoke out of the exhaust Apparently it's really fun to ride, small and nimble instead of big and powerful.
In the 14 years I've worked here, I've seen it reassembled after a rebuild, ridden on the road once and then it extruded a piston through the carb on the first session of the first track day. Now it's back where it was when I moved here...
OK, yeah...that does look interesting. Wrong somehow, but interesting.
You never know what is actually being patented. The patent could be granted for putting a Gurney bubble on the valve cover or for turning the cranks sideways or anything else.
"The primary goal of the moment cancelling engine, according to its inventor, is smoothness, simplicity and compactness."
So basically a rotary with more moving parts and complexity than a typical piston engine.
yeah, point the cranks of two rotaries right at each other. Done.
To be fair, this engine will have some advantages over the rotary, such as reasonable fuel consumption and longevity
tuna55
MegaDork
9/3/15 10:40 a.m.
Dr. Hess wrote:
You never know what is actually being patented. The patent could be granted for putting a Gurney bubble on the valve cover or for turning the cranks sideways or anything else.
You do know exactly what it patented because you can look it up!
https://www.google.com.ar/patents/US9103277
The claims are odd. He doesn't write patents well because he's limited himself artificially and unnecessarily (see claims 2, 3, 4, 6, 7, 8).
Anyway, the square nature of the engine is included specifically, and honestly it seems like a terrible idea. To somehow bank on the reduction of gyroscopic forces and an improved balance at the expense of the gear efficiency and increased parts count and subsequent reliability doesn't sound like a tradeoff that would be made in the marketplace.
Hasn't counter-rotation been done with oval track engines? I'm thinking Smokey Yunick here...
NOHOME
UberDork
9/3/15 11:11 a.m.
The claims on that patent are weird to say the least.
Another thing to keep in mind, is that you can patent just about anything, but you can't necessarily defend it. I would not be surprised to see this fall apart in the face of an obviousness challenge.
What I see is a "Remainder Patent" I bet that they started with a huge long list of claims and a gun-ho patent attorney, then one by one, the patent office whittled it down till they were left with some trivial remainder that the office would approve. And a huge attorney bill. Since you are already in for a whole lot of money at that point, you might as well go ahead so you can hang a plack on the wall.
tuna55
MegaDork
9/3/15 11:16 a.m.
NOHOME wrote:
The claims on that patent are weird to say the least.
Another thing to keep in mind, is that you can patent just about anything, but you can't necessarily defend it. I would not be surprised to see this fall apart in the face of an obviousness challenge.
What I see is a "Remainder Patent" I bet that they started with a huge long list of claims and a gun-ho patent attorney, then one by one, the patent office whittled it down till they were left with some trivial remainder that the office would approve. And a huge attorney bill. Since you are already in for a whole lot of money at that point, you might as well go ahead so you can hang a plack on the wall.
Yes. Essentially if someone does the exact same engine, but has a bore of 2.9999", they can manufacture it without infringing. Goofy.
shadetree30 wrote:
Hasn't counter-rotation been done with oval track engines? I'm thinking Smokey Yunick here...
Smokey did a reverse rotation engine for Indy years ago, but all the engine was going the same way.
yamaha
MegaDork
9/3/15 12:42 p.m.
GameboyRMH wrote:
To be fair, this engine will have some advantages over the rotary, such as reasonable fuel consumption and longevity
Diesel Wankel's are still in use to this day.......perhaps they just selected the wrong fuel for them....
I see the Suzuki RGV 500 has already been mentioned, but yeah, counter rotating cranks on motorcycles are old news.
At this point, I don't think you could invent something truly new for ICEs.
Every rotating element generates gyroscopic forces.
They can't be 'cancelled out'.
Didn't the Germans use Diesel Wankel engines when they bombed Pearl Harbor?
HappyAndy wrote:
At this point, I don't think you could invent something truly new for ICEs.
That's funny.
There is a lot of new stuff being invented- just not on a macro level of the engine. There have been some interesting ideas over the last few decades, but none of them have made it into production.
Back in the 80's, I had a promo document of a piston engine that was really interesting- and I can't really describe it- except that the horizontal pistons of this 12 cyl engine were parallel with the output shaft. Pretty neat idea. And we had Orbitals ideas that were in conjunction with their direct injection stuff.