Pollution from a HT Engine

[darwin]

I want to know when are the greenies gonna blow up all the volcanoes spewing **** into the air, all those cows farting cant be good either so no more steaks or burgers ok. Unless I see a greenie driving a bicycle and eating pure minerals and just using solar power they can stfu. Plants pollute by giving up oxygen...........5 years ago coffee was bad and now it has antioxidents in it so they say drink up.RRRRRRRRRRRRRRRRRR!

 

[teamgorillaracingTGR]

blow up valcanos!! its not thier fault! its chuck norris! he burped in austrailia and it put a hole in the ozone!!!!!!!

 

[duivendyk]

A theory can be validated by observation,not by computer models,a model based on the theory can be used to see if the predictions it produces are in accordance with observable facts. If so the model is validated and in turn the theory (or theories) can be considered validated.Atmospheric physics is exceedingly complicated and a complete model extremely difficult to construct,so usually simplified models are resorted to,but that may ignore important factors.The world's fastest and largest supercomputers are being pressed into service to gain more insight.Our atmosphere is crucial to life on the earth and the biosphere has in turn has profoundly affected the atmosphere. For instance all the oxigen in our atmosphere has been produced by plant life.By the way it's the belching of cows that produces the methane, not events downstream.

 

[dwsutton]

By the way it's the belching of cows that produces the methane, not events downstream.

Dont the cows eat the plants that produce O2 ? mooooooooo

 

[duivendyk]

Cows,plants and O2

That keeps things on an even keel,otherwise the O2 concentration would keep on increasing and we could end up with a yard long cockroaches as happened during the Permian period (300 million years ago) when the O2 went up to 35%, at present it's around 20% I think.Count your blessings,maintaining an equilibrium matters,most sudden changes such as suddenly and drastically changing the heat balance of the planet, as we are presently doing is likely to have nasty consequences for existing life forms such as Homo Sapiens? ?,the cockroaches,&centipedes would be doing great though.Count your blessings and don't rock the boat,it might capsize.

 

[duivendyk]

Simple 2 stroke engines using crankcase induction are marvels of simplicity,but emit lots of HC's and oil residues,so they are not all that easy to clean up. There was a Australian fuel injected 2 stroke design developed about 20 years ago,but it never got off the ground apparently, I don't know why,ahead of it's time ? or NIH?
I my opinion present engine design trends make little sense.Why build such complex DOHC 4 valve engines,that of course do have excellent high end performance,when they hardly ever used full throttle at say 6000 rpm or higher? (Who wants to give his automatic transmission the third degree,these things are expensive to fix).Any plain vanilla, torquey lower rpm pushrod design would have served just as well and be cheap to build and easy to maintain. No belts (horror) or chains.I am thinking here of the small block US V6's and V 8's. Not sexy for sure, but simple, dependable and efficient and with lots of grunt!

 

[arceeguy]

Simple 2 stroke engines using crankcase induction are marvels of simplicity,but emit lots of HC's and oil residues,so they are not all that easy to clean up. There was a Australian fuel injected 2 stroke design developed about 20 years ago,but it never got off the ground apparently, I don't know why,ahead of it's time ? or NIH?
I my opinion present engine design trends make little sense.Why build such complex DOHC 4 valve engines,that of course do have excellent high end performance,when they hardly ever used full throttle at say 6000 rpm or higher? (Who wants to give his automatic transmission the third degree,these things are expensive to fix).Any plain vanilla, torquey lower rpm pushrod design would have served just as well and be cheap to build and easy to maintain. No belts (horror) or chains.I am thinking here of the small block US V6's and V 8's. Not sexy for sure, but simple, dependable and efficient and with lots of grunt!

The Australian company you are referring to is Orbital Corporation Limited. The technology is alive and doing very well in Mercury Outboards, Sea Doo PWC's and scooters from well known names like Aprilia and Piaggio. I remember reading about the 2 stroke direct injection technology over 20 years ago in Popular Mechanics. They had a Ford Escort equipped with an Orbital 3 cylinder two stroke capable of great fuel economy, great performance, and low emissions. Problem is that emission standards quickly surpassed what these engines were capable of in automobiles, but since motorcycles and boats have more relaxed standards - the technology has found a home. Problem is that it makes a simple design overly complicated IMO. I'd rather have a carbureted 4 stroke than a electronically direct injected 2 stroke on my scooter, thank you very much. I suppose the expense and complexity are worth the weight savings in certain applications. (outboards, etc)

I agree with you on the DOHC 4 or 5 valve per cylinder engines in cars. Pushrod engines can have good power, efficiency and low emissions along with being VERY tolerant to neglect. (lack of regular oil changes, etc)
I had a 88 Chevy with a pushrod V6 that would snap your neck with the torque it would deliver, and get 25+ mpg on the highway. I kept it almost 200,000 miles before I sold it to a pizza delivery guy. Never even had the valve covers off that engine. "Bulletproof" is the proper description. I have a Jeep now, and that has a 4.0 inline six (a la AMC Pacer) with EFI. I expect that the engine will run 200K without much attention.

 

[teamgorillaracingTGR]

v6 with snap your neck torque? lol!
have you ever driven a pre smog era v8?

i think that we could do better with emisions definatly but these two strokes are hard cause they are meant to run negative backpressure! the best thing you can do is run biodegradable oil! i use redline oil which is better than the junk you get from castrol lucas oil or anyone else!

 

[JemmaUK]

v6 with snap your neck torque? lol!
have you ever driven a pre smog era v8?

i think that we could do better with emisions definatly but these two strokes are hard cause they are meant to run negative backpressure! the best thing you can do is run biodegradable oil! i use redline oil which is better than the junk you get from castrol lucas oil or anyone else!

Its not necessarily the engine that will give you whiplash, its the gearing and the final drive that make the difference. My father had a 2 litre Cavalier SRi in the early 80's that would probably still knock socks off equivalent cars today - merely because it had a close ratio racing gearbox that came as standard.

Modern two strokes dont actually throw that much out, hence you see an 80's two stroke motorbike and it looks like half the british fleet on maneuver there is that much smoke, yet you look at one of the Tanakas or something and there is almost no visible fumes. The trick would be some sort of one way valve on the aircleaner side of the carb that would stop fumes getting to atmosphere on over run and in similar situations.

Another idea would be to use EGR in two stroke engines, as is used in Tier III/IV diesels - an idea ideally suited to two strokes since even the best of them throw out some unburned HC's in their exhaust (actually, so do 4-strokes). This'd be complicated to set up and need tight control but it could be done.

Jemma xx

 

[ChinaPhil]

"all those cows farting cant be good either so no more steaks or burgers ok." It would seem that Australia has the solution, 'Eat kangaroo to save the planet' http://news.bbc.co.uk/2/hi/uk_news/7551125.stm