The Forestry Forum

General Forestry => Chainsaws => Topic started by: 567paloggger on March 16, 2009, 08:51:54 PM

Title: 2010 epa emissions
Post by: 567paloggger on March 16, 2009, 08:51:54 PM
does anyone knows about the new 2010 epa emissions i keep hearing rumors on how the new chainsaws are gonna be junk not have power does anyone actually know whats going to happen should we buy a couple of 08 and 09 chainsaws to keep as a backup thanks
Title: Re: 2010 epa emissions
Post by: zackman1801 on March 16, 2009, 09:14:49 PM
The new saws are an entirely different beast than the saws of today. They have power in different ways. Although a few good examples of saws to look at are the Ms441 and the Husky 575 and 576, they are the new breed of EPA saws. I do know of people who are anticipating the coming saws and are buying up a few extra saws to use, but i also know of people who are using 441s and are happier with them than they are the 440 they used to have. I guess to say for sure you would need to demo the saws and see if it fits your fancy.
Title: Re: 2010 epa emissions
Post by: markct on April 15, 2009, 01:00:56 PM
so whats different about these saws in the way they are built? are they a 4 stroke design or something totaly different, i can understand and deal with i think different power but im more concerned about maintenance and longjevity
Title: Re: 2010 epa emissions
Post by: sawcollector on April 16, 2009, 01:51:12 PM
EPA phase 3 in 2010 deals with evap and permeation emissions, not exhaust. The EPA has basically said that exhaust emissions are probably as good as the technology can get them for hand held and rolling small engines, so now they want the manufacturers to make changes so that hydrocarbons can't permeate through the poly tanks or fuel lines, or evaporate through fuel caps or tank vents, and I recall seeing that Kohler is putting a charcoal canister on some of their engines so maybe even the fumes off the carb bowl have to be captured. I have seen that the fuel caps on B&S mowers are big and bulky because they have a charcoal trap in them for tank venting.
What STIHL is doing with each new model of saw is an engine technology called stratified scavenging, which introduces a little puff of clean filtered air into the combustion chamber between the burnt exhaust gases flowing out and the incoming fresh air-fuel-oil mix coming from the crankcase. The clean air scavenges out the exhaust and holds the fuel charge back for a fraction of a second to allow the piston to come back up and close off the ex port before the fresh fuel leaks out, called scavenge loss. The net result is lower emissions but also up to a 20% increase in fuel economy, which is a good thing. The two-stroke is not going away and to my knowledge STIHL is not going to build a four-stroke saw. Other manufacturers are also building engines with this technology, it is not exclusive to STIHL.
If you cut with a MS 441 side by side with a MS 440 the difference is noticeable. And the 441 will cut several minutes longer on the same amount of fuel.
On the other hand everything is running leaner today than in the past. A MS 390 today is different than an old 039. It has a different carb, cylinder, bearings, and runs at a higher RPM on less fuel, but all the older designs will eventually be replaced with a newer design. And the new saws are a worthy replacement and will most likely be good performers.
Maintenance and upkeep will be about the same but there is no doubt that a high quality saw built to meet current EPA standards will cost more today than saws did in the past, but at least we can get better fuel consumption to help offset the cost.
Title: Re: 2010 epa emissions
Post by: baronthered on April 18, 2009, 02:25:16 AM
I understand the worry about performance and life of the saw. The major companies will still make saw that produce or they wont make any money.
Title: Re: 2010 epa emissions
Post by: inspectorwoody on April 18, 2009, 01:57:00 PM
I spoke with my local Stihl dealer in regards to this.

He said the whole product line has to meet the epa regulations.

Sounds like they will pass the emissions rules on to weed eaters etc.

Curious to see what happens.
Title: Re: 2010 epa emissions
Post by: markct on April 20, 2009, 06:52:43 PM
so if this is mostly about evaporative emissions why would that affect how the saw runs or performs any?
Title: Re: 2010 epa emissions
Post by: sawcollector on April 20, 2009, 09:15:31 PM
I guess we need to back up a bit. In 1996 the EPA told the small engine industry to start cleaning up the exhaust, and the lower emissions numbers would be phased in to the lowest level by 2007. That was Phase 1 and Phase 2. Phase 3 is for 2010 and it deals with evap emissions. SO the EPA has basically said that the exhaust is about as clean as can be done within reason, so now do something about the materials used for the tank, lines, hoses, and any vapors that can vent to atmosphere.
So no more poly blow molded tanks unless that are sealed with something internally. Most will be molded from two parts and welded together using a plastic that is denser. Fuel lines and hosed will be of a higher grade material than in the past. Tank vents will be positive sealing types, or have charcoal to capture vapors.
So as far as I can tell, STIHL will be using strat scavenge designs on the engines from here on out, as will other manufacturers, and there will not be a need for any further changes such as a cat muffler.
And all of this already applies to all hand held engines, not just saws.
EPA allows a manufacturer to accumulate credits and carry them over to the next year, or sell them to someone else, and average the emissions between different models. So an older engine design that has higher emissions than the baseline can be sold as certified if some other models below the baseline are sold to offset or average out the total emissions for all of them together.
Typical, complicated govt. mumbo-jumbo but everybody has to play by the same rules.