what is "strato charged"

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I'm convinced that the "stratocharged" engine will be the saw of the future, just to comply with the EPA. I'll just be glad when tech's understand them so they will run well at altitude. Not trying to be a stick in the mud, but the stratocharged saw's are real dog's at 9000'.

Andy

Completely worthless at altitude. Unfortunately, I think that all of them well be in a few years.

But technecally, if it puts out a third less emissions but has to run twice as long (yes, they are that slow at high altitude), isn't it causing MORE polution. Kind of like a water saver toilet you have to flush 4 times to get the turd down.
 
I think that this technology will only be around for a short while, and then it will all go to 4 strokes. From what I have heard, the main small engine companies all have designs developed for the 4 strokers. CA CARB regulations and EPA requirements loom ahead. 2010 is a cut-off date for small hand held engine manufacturers to meet the emissions requirements for EPA. Many saws today already cannot be sold in CA. There are also European emissions standards, and there will no doubt be more regulations put into effect after 2010 by the EPA, CARB, and Europe.
 
Completely worthless at altitude. Unfortunately, I think that all of them well be in a few years.

But technecally, if it puts out a third less emissions but has to run twice as long (yes, they are that slow at high altitude), isn't it causing MORE polution. Kind of like a water saver toilet you have to flush 4 times to get the turd down.

Romeo that last line got me laughing so hard I almost hacked up a lung. It got me thinking though.......... I must have a water saver toilet.
 
thanks for setting the book strait on the 441, #1.


strato, then 4stroke, :censored: .


i have been told there are some other developements coming to saws that will offset the engine setbacks.


:confused:



so the answer is yes they will have a better mousetrap but how long before they get it right?


:jawdrop:
 
I think that this technology will only be around for a short while, and then it will all go to 4 strokes. From what I have heard, the main small engine companies all have designs developed for the 4 strokers. CA CARB regulations and EPA requirements loom ahead. 2010 is a cut-off date for small hand held engine manufacturers to meet the emissions requirements for EPA. Many saws today already cannot be sold in CA. There are also European emissions standards, and there will no doubt be more regulations put into effect after 2010 by the EPA, CARB, and Europe.

I'm betting 10 year or more for "basic strato" .. maybe that's short.. but.. and it may well evolve with electronic carb/injection contols way beyond that.. Of course.. strato with cat! Very likely for the small machines...

The European regs are bascially a mirror of the EPA regs, but with no credits.
 
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Stihl #1 - Fantastic posts. It is so helpful to have a process explained in terms that we can understand. Thanks for sharing your knowledge.
 
:ices_rofl:

"The $13-billion-a-year farm machinery giant had come up with a low-emission technology for its Homelite line of two-stroke consumer handheld products, which it had purchased only a few years before. The design, called compression wave, is similar to RedMax's stratified design. What was not similar was the full-court press that Deere's lobbyists put on the EPA to persuade the agency to stick with the more stringent Phase II standards, despite the howling protests of PPEMA. Deere's efforts paid off, as the EPA adopted the tougher standards in July 1999.

But what happened next was bizarre. Although Deere licensed the technology to Stihl, not a single product embodying it has ever reached the market. Last November, moreover, Deere sold the Homelite division to TechTronics Industries (TTI) of Hong Kong. Under a squeeze from big-box retailers, Homelite had lost $100 million in 21 months. Deere has few friends in the handheld industry today. "What's fascinating is that Deere persuaded the EPA, and then the industry gets screwed," says an industry source closely involved with the EPA. Deere won't comment, but in fairness it must be said that its intense lobbying efforts may have incited fresh waves of innovation among the handheld manufacturers. "

Nothing runs like a Deere............

This is interesting, Pest, as back in 95 or whenever the meeting was with the EPA most manufacturers were telling the EPA we can't hit the numbers you are asking us to lower emissions to, and then JD showed up with a prototype engine and said "sure, no problem, we have a technology right here that can do it". So the EPA said if they can do it everybody can do it. Now this is just heresay but the story I heard was that some dude came up with the idea, built a modified Homey trimmer engine that used compression wave injection to dramatically lower scavenge loss, in his garage, and managed to sell it to JD. And they went to this EPA meeting and shot from the hip with no real testing or R&D on the design, just a dyno run that showed low HC exhaust.
And as the article said, supposedly Stihl tried it and decided not to market an engine with this technology. Something about cold weather running not being consistent, but I am not sure about that.
So I agree with the article in that JD probably does not have any friends left in the hand held business, but their actions did cause the industry to come up with some ideas that we are now seeing on the new models of saws. And more new stuff will no doubt come. Whether we like it or not. But the end result will be lower emissions which is a good thing, and better fuel economy, which is also a good thing, and the end of the conventional piston ported two-stroke, which is a sad thing. I used to teach auto tech at the high school level. I told the kids about my 65 big block vette roadster. 25 hp, 8mpg, raw low-tech, no replacement for displacement HP. Then the 70s and 80s with smogged up slug engines in everything. Jump to now. I showed them a video of the Venom Viper. I forget the details but basically a 500 to 600 hp v10, fuel injection, 200mph, 1/4 mile in 10 seconds, and can be driven daily and get 18 mpg. That is high-tech HP. And what has happened to the auto industry is trickling down the the power equipment industry. Ignition modules with automatic timing adjustment. Electronic carbs. Cat mufflers. I suspect some form of fuel injection for hand held stuff. Who knows what is next. So stock up your collection of saws trimmers and whatever else you like with recent models and examples, then sit back and lets enjoy the ride!
 
Stihl #1 - Fantastic posts. It is so helpful to have a process explained in terms that we can understand. Thanks for sharing your knowledge.

Thanks Steve, my pleasure.

The rep bar just keeps getting longer!!! LOL
 
Deere wishes they bought it cheap.....it was an adaptation from their failed diesel technology of the same name
 
Eddie

Great info my friend, nice posts indeed. You still have more saws than me so I refuse to rep you,LOLOLOLOL, just kidding.

Now tell us if this is true. A little birdie told me, well one about 6'3 235 lbs named Kevin, that fuel injection is on the way. He esitmated within 10 years but it is being put on the drawing board now and is being considered and he felt it would be on small power equipment when all is said and done. That should really clean up the emmisions just like it did auto's. Have you heard anything about that???
 
Compression Wave Injection

So here is CWI (compression wave injection)

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The carb looks similar on the outside but is totally different in what it does. The low pressure is created in the crankcase by the piston moving up. Some air and fuel-oil mix go into the crankcase in the usual manner, about 15%, to provide lubrication to the bottom end. And this is supposed to be enough. So why are we at 50:1? Anyway, the rest of the fuel the engine needs is routed to the compression wave tube. The tube is long and wraps around the intake flange.

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So when the piston is at TDC the fuel is being drawn further around the tube but never makes it to the crankcase. Notice that the top of the tube is closed by the piston skirt.

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Now the piston is moving down building positive pressure in the crankcase which is pushing back on the fuel in the tube. The pic doesn't show it but there is a check valve that keeps the fuel from being pushed back into the carb. And again, notice that the top of the tube is still closed by the piston skirt.

attachment.php


So now the piston has come down far enough to open the exhaust port so ex gases are flowing out. And the transfer port is open, so the extremely lean air-fuel mix comes in and loop scavenges the ex gas out, but also notice that the top of the compression wave tube is also open, exposed to the hot, high pressure combustion gas. That little squirt of gas pushes on the fuel and adds pressure in the tube, pushing the fuel towards the crankcase, but now the bottom of the piston skirt has closed the tube so the fuel is being compressed in the tube.

attachment.php


So now the ex gas pressure has bled down through the open ex port, and the piston has started back up to close the ex port, and the pressure behind the fuel in the tube is higher than the pressure in the combustion chamber, so fuel now is injected into the air that came in from the crankcase, mixing with it to Lambda = 1 or so, and the delayed injection of this fuel gives the piston time to close the ex port, so scavenge loss is less. Emissions are lower, and fuel economy goes up. All well and good in theory, but it is my understanding that with the liquid fuel sloshing around in the tube, the engine would run erractically and that it was sensitive to tuning and temperature.
So for what it is worth that is how CWI works. Next post is a pic of the parts.
 
Here is a pic of the JD motor.

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The clear tube is the compression wave tube, and there are extra holes in the cylinder wall and flange that correspond to the openings depicted in the drawings. This is the only pic I have, so the drawings in the previous post explain it better.
 
Great info my friend, nice posts indeed. You still have more saws than me so I refuse to rep you,LOLOLOLOL, just kidding.

Now tell us if this is true. A little birdie told me, well one about 6'3 235 lbs named Kevin, that fuel injection is on the way. He esitmated within 10 years but it is being put on the drawing board now and is being considered and he felt it would be on small power equipment when all is said and done. That should really clean up the emmisions just like it did auto's. Have you heard anything about that???

You heard what? From who? Man you better check your sources. A company like Stihl, thinking about something as modern and as high tech as fuel injection on a chain saw!!! I can't imagine!!! LOL

And I will always have more saws that you. He who dies with the most stuff wins, right?

Actually I plan on going to heaven when I die, and I bet there is a cool saw collection in God's house!
You want me to leave my saws to you? You are so ornery I bet you out live us all!:)
 
Do you have a pic of the Stihl saw that they converted?

My understanding is that it was a small hedge trimmer motor that it was tried on, not a saw.
I think JD did market a saw with this induction on it, but I don't know what model.
 
I am pretty sure it was an 044 but it may have been a 036......that was a long time ago.....and so much of that stuff has vanished like it never happened

I hate cloak and dagger carp

They tried to corner the market of all 2 stroke engines by leveraging something they didn't have yet.....
 
I never saw it run but I remember that was why the larger hand held engine emissions reductions were set where they were
 
Pest, you are right that there was a direct fuel injection 044 (I think) built as a R&D project back in the early 90s or late 80s. I have seen a pic of it, not the actual saw. To my knowledge it was never marketed, it was just an engineering exercise.
 
You heard what? From who? Man you better check your sources. A company like Stihl, thinking about something as modern and as high tech as fuel injection on a chain saw!!! I can't imagine!!! LOL

And I will always have more saws that you. He who dies with the most stuff wins, right?

Actually I plan on going to heaven when I die, and I bet there is a cool saw collection in God's house!
You want me to leave my saws to you? You are so ornery I bet you out live us all!:)

You are planning are ya, thats good, me I'm orenry, not really, when ya going,LOLOLOLOLOL

OKOKOKOKOK, I see somethings aren't supposed to be mentioned. You answered my question. I can't wait to see how they run, :cheers: :cheers: :cheers:
 
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