4-strokes release more carbon monoxide than 2-strokes?!?

Discussion in 'General Questions' started by sparky, Nov 9, 2008.

  1. sparky

    sparky Active Member

    Go here: http://www.envirofit.org/challenges_solutions.html & click 2-stroke retrofit, then benefits...

    It's nice to see numbers sometimes, and this technology seems to solve lots of problems at the same time. This + NuVinci = LOVE.

    Also, check out that little stove that burns wood more efficiently for the more than 50% of our planet that's still using open fires to cook. Good stuff.

  2. JemmaUK

    JemmaUK Guest

    COx was never the two strokes problem... its the NOx that is its achilles heel.

    Chrysler was close to releasing a two stroke version of the Neon Series 1 but they eventually shut the programme down because of difficulties getting the vehicle to the california statute levels re pollution..

    It was apparently quite an advanced motor although the problems would have likely been eliminated if they had used the stratigraphic scavenging method as used in the Tanaka engines as opposed to the cat converter method

    Jemma xx
  3. DesmoDog

    DesmoDog New Member

    I worked on the exhaust for that engine. Three cylinder, supercharged. Didn't put out nearly the power I would have expected, and had a low rpm limit. I suspect that was to avoid overspinning the blower but no one there would confirm that.

    One of the neat things about it was, if you took the top ten warranty issues on their (then) current engine, the two stroke didn't have something like 9 of those parts...
  4. JemmaUK

    JemmaUK Guest

    I think that was during the MB ownership period.. where things slipped a little re quality control in some respects... also MB parts werent as strong as some of the others..

    It would have been interesting to see a properly engineered 2-stroke SRT version.... that would have *really* put the wind up some other manufacturers.. although the mixing thing would probably have been an issue with people..

    BL did a 3 cylinder 4 stroke back in the 80's. Was supposed to go into the Metro but the engine was canned about which there is a funny story..

    Apparently one of the managers who was responsible for canning the 3 cylinder engine (60hp from 1000cc, impressive back then) was lent a factory test mule for a spin to see what he thought of it... word is he came back happier than a pig in slurry about the cars performance with whatever engine it had been fitted with... only to be told with some asperity that the programme he'd just canned (along with all the prototype tooling and such...) was the engine he'd been raving about for 10 whole minutes by the clock!

    They were probably even more sick when one of the japanese companies came out with a similar motor which can be run up to 200hp!! with the relevant turbo and intercooling etc..

    Saddest thing about the whole story - they came up with a prototype that would be modern today... and binned it for something that looked ancient even back then *sigh*... no wonder they went broke 3 times..

    Jemma xx
  5. DesmoDog

    DesmoDog New Member

    That's the beauty of using a blower on it - no need for crankcase scavenging so no need to mix oil/gas. From a consumer standpoint it was no different than any other Neon. Put gas in it when it's out, change the oil every 6000 miles (or whatever) and never quite figure out why the three cylinder sounds like an inline six... :grin:
  6. JemmaUK

    JemmaUK Guest

    That makes alot of sense.... apart from the blower overspeed part...

    If you know that part of the engine is weak in testing... then you build a stronger assm. to run to the relevant speeds as required... quite why thats so much of a problem I dont know.. I smell the stench of inane management methinks...

    Would have been fun to see the look on the faces of the petrol heads in the immaculate 440 6-pack... when the owner of that lil neon down the road forgot to tell him about those nice tuned pipes he picked up.. although that would have probably required a montgomery scott on the exhaust valves ...

    yarrgh.. I just realised it was a piston ported engine..! no wonder it was a gutless wonder... and that was also why the NOx problems reared their ugly heads so badly as well... *sigh*.

    why on earth didnt they use schneurle porting like on the tanakas/CIF/JDL motors?... I think the last piston ported cyclemotors were probably the french solexes..

    on the upside... tuned pipes would work to some degree with that motor :)

    Jemma xx
  7. arceeguy

    arceeguy Active Member

    I thought HC's from poor scavenging was the two stroke Achilles heel?
  8. DesmoDog

    DesmoDog New Member

    Oh I wouldn't be too hard on them. It was never meant to be a race engine so high power wasn't in the design requirements. I'm guessing they designed it for the everyday driver who would rarely rev it over 4000rpm anyway. And to be honest for a car it wasn't THAT low, under 7000, around 6000 maybe? I know a lot of people will read that and think it's typical, and it is... but for what it COULD have been. At the time I was driving a 2.0L Nissan with a 7200 rpm redline. My thought was it COULD have been a screamer, but wasn't. But of course it was never intended to be.

    Now... if the AFTERMARKET had gotten ahold of it... (where's that evil grin smilie???)

    The porting was unlike anything I had seen before (which isn't saying much) very narrow but long - extending along quite a bit of the circumference of the cylinder. It made the ports on my RD350 look positively ancient technology!

    Regarding the emissions - they did a boatload of Computational Fluid Dynamics on it and thought they could beat that. However as I heard the story, the guy who was spearheading the whole program got brain cancer and died rather suddenly. The group never got the same support after that and faded away.