daeman
Reader
9/3/15 7:49 p.m.
There will always be innovators, its just a case of whether the innovations made are sutible for mass production etc.
The miller cycle is an interesting innovation on a normal piston engine.
The sarich orbital poses an interesting alternative to the wankel.
The sarich was once lauded as the future of engines by the head of Renault...
There's plenty of new and alternative variants being worked on and developed all the time, whether they are viable for use outside of being a prototype or experimental engine is another story.
chiodos wrote:
Dr. Hess wrote:
Didn't the Germans use Diesel Wankel engines when they bombed Pearl Harbor?
Cant tell if serious....
And not familiar with delta house...
alfadriver wrote:
And we had Orbitals ideas that were in conjunction with their direct injection stuff.
Whatever happened to the Oribtal 2 stroke engines anyway. Direct injection got adopted widely on 4 stoke automotive ICE's. I am curious.
Do you have the patent numbers and I can tell you the difference
Type Q wrote:
alfadriver wrote:
And we had Orbitals ideas that were in conjunction with their direct injection stuff.
Whatever happened to the Oribtal 2 stroke engines anyway. Direct injection got adopted widely on 4 stoke automotive ICE's. I am curious.
Last I was aware we worked on them was 20 years ago- two strokes are just not efficient enough, and could never get the emissions to be good enough.
It's too bad- there were some solid ideas to fix a few of the problems, alas, not enough were solved. For car engines, at least.
Boat engines, on the other hand, DO run DI and are clean enough. Pretty clever system, too- much like a magneto ignition system, the DI systems are self energizing (and pumping, too)- so they can pull start. I know a few schools have managed to use that technology on snowmobiles that are clean enough to run in Yellowstone (which have really tight emission rules).
So it's not dead- just used for different applications.
alfadriver wrote:
Type Q wrote:
alfadriver wrote:
And we had Orbitals ideas that were in conjunction with their direct injection stuff.
Whatever happened to the Oribtal 2 stroke engines anyway. Direct injection got adopted widely on 4 stoke automotive ICE's. I am curious.
Last I was aware we worked on them was 20 years ago- two strokes are just not efficient enough, and could never get the emissions to be good enough.
It's too bad- there were some solid ideas to fix a few of the problems, alas, not enough were solved. For car engines, at least.
Boat engines, on the other hand, DO run DI and are clean enough. Pretty clever system, too- much like a magneto ignition system, the DI systems are self energizing (and pumping, too)- so they can pull start. I know a few schools have managed to use that technology on snowmobiles that are clean enough to run in Yellowstone (which have really tight emission rules).
So it's not dead- just used for different applications.
Evinrude would like to differ with you sir!
The problem is the same with the rotary. You are going down a path alone because everyone else was already ahead on 4 strokes and decided to stick with what gave them a head start. You can get 2 strokes where they need to be. Most manufacturers just didn't research. Add that to a secondary maintenance step (adding oil to injector reservoir) and you have a tech that is niche. Just like the rotary.
2 strokes can do it, there are just other market factors at play.
Keith Tanner wrote:
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.
UPON FURTHER REVIEW:
Oh, I get it now...
I would think that most of the advantages might be negated by friction?
In reply to Flight Service:
Couple of things- that's one of 3 things that are tested- in addition to CO, there is HC (or NMOG) and NOx. Since two strokes pass some air on every event- reducing all of those with a catalyst is really, really hard.
The other thing- 11k ppm CO on a 4 stroke with a catalyst? Maybe when running super rich to protect components. Otherwise, most of the time, the CO is below 200ppm. HC and NOx are in the 10ppm range these days. That number looks pretty bogus for the non 2 stroke examples. Especially since it's a boat example, where the engine is running a constant speed/load for the test.
Everyone did the research, it's that nobody got far enough. 2 strokes are way cheaper to make than 4 strokes- so it's not as if there is not a massive incentive. Some even came up with ways to have two strokes with an isolated crank, so that the oiling system was not changed from a 4 stroke.
In reply to alfadriver:
Yes, I am aware of that. Evinrude got there.
When I was talking to the guys at Merc and Yamaha, they said exactly what I posted.
In reply to Flight Service:
Oh, you were referencing boats not cars.
No idea what they did.
T.J. wrote:
AngryCorvair wrote:
chiodos wrote:
Dr. Hess wrote:
Didn't the Germans use Diesel Wankel engines when they bombed Pearl Harbor?
Cant tell if serious....
And not familiar with delta house...
Forget it, he's rolling.
And the long awaited answer for Senator Blutarski is- NO. It was not over when the Germans Bombed Pearl Harbor.
