- Joined
- Jul 27, 2010
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- 5,485
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- Location
- Blouberg, Cape Town
- Bike
- KTM 890 Adventure R
Interesting notes on emission standards from Denmark:
In 2006 we saw the first strict emission standards that forced the switch from carburettors to electronic fuel injection. The mechanically based carburettor was simply not accurate enough to keep the air/fuel ratio within the required (lean) limits.
Back then, there was slightly different standards for different countries, and we saw certain motorcycle manufacturers selling their product line in different versions, modified to meet the local requirements.
Today, the current emission standards still have local names, but they are very close to being similar to each other around the world, and the motorcycle factories are now mostly launching “world models” – i.e. no more local variants that will stress their production logistics a lot.
2020 marks the introduction of even tighter emission regulations and our bikes will suffer even more than before. The required air/fuel ratio is now so lean that it will be critical for quite a few of the existing motorcycle engines, and a number of the engines we know and love will be phased out in the near future.
The big problem is that combustion temperature goes up as the air/fuel mixture is made leaner and especially the air cooled engines will have a hard life. So the engines without liquid cooling will either disappear or be detuned to reduce the power output (lower power = less heat). Oil cooling channels around the exhaust valves and the use of high spec (expensive) materials will probably make the air cooled engines stay with us a few years more, but there is no doubt that we will see fewer air cooled engines in the future.
Modern liquid cooled engines will have increased cooling capacity, especially around the very hot exhaust valves, and we already see cooling systems with higher capacity on the newest engines.
The emission standards are designed for cars but enforced on the motorcycle engines too. And if we look beyond the cooling issue, the lean mixture requirements are not really a major issue for the car engines because they have a big and heavy flywheel and in general a high rotating mass on all internal parts.
Things are much worse for our motorcycle engines because of the very light internal parts and no flywheel. This means that the motorcycle engine does not have sufficient rotating mass to smooth out the low speed running, and the result is poor on/off like throttle action, and weak low speed running. This makes the bike difficult to ride and it is potentially a safety issue.
Another important thing is that the poor low speed running often means that we have to ride the bike one gear lower through town than normally necessary – to get the revs up so the bike will run reasonably well. Higher RPM means more noise and more pollution, so the emission standards do not really make sense for motorcycles.
So, despite all the fancy technology in our modern engines, they need the small controlled fuel enrichment from e.g. the BoosterPlug more than ever.
Disclaimer: I have a personal interest in BoosterPlug, but the info is interesting nonetheless.
In 2006 we saw the first strict emission standards that forced the switch from carburettors to electronic fuel injection. The mechanically based carburettor was simply not accurate enough to keep the air/fuel ratio within the required (lean) limits.
Back then, there was slightly different standards for different countries, and we saw certain motorcycle manufacturers selling their product line in different versions, modified to meet the local requirements.
Today, the current emission standards still have local names, but they are very close to being similar to each other around the world, and the motorcycle factories are now mostly launching “world models” – i.e. no more local variants that will stress their production logistics a lot.
2020 marks the introduction of even tighter emission regulations and our bikes will suffer even more than before. The required air/fuel ratio is now so lean that it will be critical for quite a few of the existing motorcycle engines, and a number of the engines we know and love will be phased out in the near future.
The big problem is that combustion temperature goes up as the air/fuel mixture is made leaner and especially the air cooled engines will have a hard life. So the engines without liquid cooling will either disappear or be detuned to reduce the power output (lower power = less heat). Oil cooling channels around the exhaust valves and the use of high spec (expensive) materials will probably make the air cooled engines stay with us a few years more, but there is no doubt that we will see fewer air cooled engines in the future.
Modern liquid cooled engines will have increased cooling capacity, especially around the very hot exhaust valves, and we already see cooling systems with higher capacity on the newest engines.
The emission standards are designed for cars but enforced on the motorcycle engines too. And if we look beyond the cooling issue, the lean mixture requirements are not really a major issue for the car engines because they have a big and heavy flywheel and in general a high rotating mass on all internal parts.
Things are much worse for our motorcycle engines because of the very light internal parts and no flywheel. This means that the motorcycle engine does not have sufficient rotating mass to smooth out the low speed running, and the result is poor on/off like throttle action, and weak low speed running. This makes the bike difficult to ride and it is potentially a safety issue.
Another important thing is that the poor low speed running often means that we have to ride the bike one gear lower through town than normally necessary – to get the revs up so the bike will run reasonably well. Higher RPM means more noise and more pollution, so the emission standards do not really make sense for motorcycles.
So, despite all the fancy technology in our modern engines, they need the small controlled fuel enrichment from e.g. the BoosterPlug more than ever.
Disclaimer: I have a personal interest in BoosterPlug, but the info is interesting nonetheless.
