Hymee gets Supercharged (Part 2)
#1276
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Miller-Cycle strategy using twin screw SC and renesis?
Hey, would it be possible to get some sort of Miller-Cycle type efficiencies with this SC on the renesis? If I remember right the Mazda Millenia S had a 2.3L Miller-Cycle engine with a twin-screw SC. Maybe someone with more knowledge on this subject can enlighten. I know most people will just want maximum power, which you will probably get by not using the Miller-Cycle, but some people like to save on gas (plus I think Miller-Cycle reduces the chance of detonation).
#1277
Originally Posted by NewtonPulsifer
Hey, would it be possible to get some sort of Miller-Cycle type efficiencies with this SC on the renesis? If I remember right the Mazda Millenia S had a 2.3L Miller-Cycle engine with a twin-screw SC. Maybe someone with more knowledge on this subject can enlighten. I know most people will just want maximum power, which you will probably get by not using the Miller-Cycle, but some people like to save on gas (plus I think Miller-Cycle reduces the chance of detonation).
--R.
#1278
the WANKEL made me do it
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A description of the Miller-Cycle at www.howstuffworks.com
The standard four-stroke engines described in How Car Engines Work are called Otto-cycle engines. They are named after Nikolaus Otto, who invented this type of engine in 1867. In the same way, Diesel-cycle engines are named after inventor Rudolf Diesel.
Ralph Miller patented his Miller-cycle engine in the 1940s, and for the last several years Mazda has been using this type of engine in some of its cars.
A Miller-cycle engine is very similar to an Otto-cycle engine. The Miller-cycle uses pistons, valves, a spark plug, etc., just like an Otto-cycle engine does. There are two big differences:
-A Miller-cycle engine depends on a supercharger.
-A Miller-cycle engine leaves the intake valve open during part of the compression stroke, so that the engine is compressing against the pressure of the supercharger rather than the pressure of the cylinder walls. The effect is increased efficiency, at a level of about 15 percent.
The standard four-stroke engines described in How Car Engines Work are called Otto-cycle engines. They are named after Nikolaus Otto, who invented this type of engine in 1867. In the same way, Diesel-cycle engines are named after inventor Rudolf Diesel.
Ralph Miller patented his Miller-cycle engine in the 1940s, and for the last several years Mazda has been using this type of engine in some of its cars.
A Miller-cycle engine is very similar to an Otto-cycle engine. The Miller-cycle uses pistons, valves, a spark plug, etc., just like an Otto-cycle engine does. There are two big differences:
-A Miller-cycle engine depends on a supercharger.
-A Miller-cycle engine leaves the intake valve open during part of the compression stroke, so that the engine is compressing against the pressure of the supercharger rather than the pressure of the cylinder walls. The effect is increased efficiency, at a level of about 15 percent.
#1279
A miller or atkinson cycle engine is where you have an expansion volume which is effectively larger than the intake volume. On a piston engine you can do that with valve timing, letting the gas flow backwards through the intake valve, or with a wacky crankshaft setup.
I'm not sure how you'd do that on a wankel. You can't change the shape of the rotor or engine block. Maybe you could have the intake port open later, or have a third port during the compression portion that bleeds off pressure.
Or there's always the wacky non-wankel atkinson rotary shown on wikipedia:
http://en.wikipedia.org/wiki/Atkinson_cycle
http://white-smoke.wetpaint.com/page/Rotary+Engine
I'm not sure how you'd do that on a wankel. You can't change the shape of the rotor or engine block. Maybe you could have the intake port open later, or have a third port during the compression portion that bleeds off pressure.
Or there's always the wacky non-wankel atkinson rotary shown on wikipedia:
http://en.wikipedia.org/wiki/Atkinson_cycle
http://white-smoke.wetpaint.com/page/Rotary+Engine
Last edited by BaronVonBigmeat; 01-12-2007 at 12:48 AM.
#1280
Registered
The miller cycle was tried on the rotary. They used an additional intake port at the 12 o'clock position on the rotor housing. This had a valve in it that fed it back into the main intake system. This valve was timed to open and close as needed to keep the intake open for longer than the exhaust.
#1283
Originally Posted by auzoom
That Atkinson Cylce Rotary looks very cool!
What happened with the Miller Cycle? You said it was tried. Did it work? Explode?
Cheers
Andrew
What happened with the Miller Cycle? You said it was tried. Did it work? Explode?
Cheers
Andrew
The Atkinson is being put in production model cars
http://peswiki.com/index.php/Directo...ralato_Ruggero
http://www.globalautoindex.com/news.plt?no=1691
Its Hybrid electrical and Atkinson rotary car. Really, really COOL! Why the hell mazda has been screwing around with a Hydrogen RX-8 that nobody will buy or can afford at this point is anybody's guess. Ford sure does not have the extra money to be playing with crap they can't sell. But a hybrid electrical and rotary hybrid can be sold.
Toyota seems down with getting a piece of the Atkinson action and has a hybrid that uses this technology.
http://www.edmunds.com/insideline/do...d=109049?imw=Y
Anyway, wished Mazda stop being nuts and get with guys like Hymee, Pettit, the AFSC, etc.... and make an official Mazda supercharger for the RX-8. It's so damn obvious that it would sell as an option for the RX-8.
#1285
Coming thru in waves...
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I dunno, looks to me like a major pita to perfect. To many detailed little creepy niknaks and doodads to get (keep) just right, not to mention having to seal-off leakage. That slider scares me. I hate sliders... Just imho, sorry... I think I like piston engines better...
Last edited by Racer X-8; 03-17-2007 at 09:12 PM.
#1289
Originally Posted by swoope
i chatted with him about two weeks ago.. he is recovering from an illness.
beers
beers
#1291
Registered
The main difference between an Atkinson Cycle and a Miller Cycle engine is forced induction. Miller cycle uses it. On both accounts you make less power than conventional timing. The key to it's use are lower emissions and better gas mileage. Don't be looking at either as a way to gain power though.
#1292
Yeah - I'm still here. Been tending to other issues for a while, but this project is moving again. I've invested to much to give it away. I've got some goodies instore, but I'd rather wait until I have something more concrete other than some CAD drawings before I let any secrets out of the bag.
The best way people can help support this project is to continue to support my existing high quality products.
Cheers,
Hymee.
The best way people can help support this project is to continue to support my existing high quality products.
Cheers,
Hymee.
#1297
Yeah - I'm still here. Been tending to other issues for a while, but this project is moving again. I've invested to much to give it away. I've got some goodies instore, but I'd rather wait until I have something more concrete other than some CAD drawings before I let any secrets out of the bag.
The best way people can help support this project is to continue to support my existing high quality products.
Cheers,
Hymee.
The best way people can help support this project is to continue to support my existing high quality products.
Cheers,
Hymee.
#1300
rot8ing
iTrader: (1)
oh man. i just finished reading this entire thread. it's so much like a roller coaster that let's you down by ending.
here's a couple q's.
Isn't pettit's sc twinscrew? I'm curious about the differences between theirs and the hymee. Living in florida means that pettit is likely a better option for me, but hymee really seems to know his stuff, and he's had this thing in r and d for over 2 years now. pettit probably could use some more r and d.
i just want a bolt on and forget it sc so bad. please make it happen for me, hymee. i really liked aus when i was there. too bad you guys spend all your time with telescopes watching the kiwis hump sheep. lol.
here's a couple q's.
Isn't pettit's sc twinscrew? I'm curious about the differences between theirs and the hymee. Living in florida means that pettit is likely a better option for me, but hymee really seems to know his stuff, and he's had this thing in r and d for over 2 years now. pettit probably could use some more r and d.
i just want a bolt on and forget it sc so bad. please make it happen for me, hymee. i really liked aus when i was there. too bad you guys spend all your time with telescopes watching the kiwis hump sheep. lol.