New Saw Technology - Who Has It, Who Doesn't?

[Sagetown]

Direct cylinder injection? Really - on a saw? Is this the system Stihl has on a concrete saw or something? Clearly that would have major benefits on a 2-stroke, although the lubrication issue would have to be dealt with. Direct cylinder injection requires a lot of pressure and would be a lot more complex.

Happy Birthday WoodHeatWarrior. :chainsawguy::wave::bday:

 

[mountainlake]

The benefit is that the injector puts the fuel where it's needed: into the combustion chamber. An auxiliary injector can be set up for the bottom end to keep the bearings happy. When the computer gets it all synchronized, very little unburned mix will go out the exhaust port and the saw will run all day, in changing conditions and also run with the poor fuel available from the pump.

I'd guess direct injection will be coming, untill then I'd rather tune my saws. Steve

 

[mountainlake]

Happy Birthday WoodHeatWarrior. :chainsawguy::wave::bday:

They've been running direct injection on outboard motors and snowmobiles for a few years now, will be only a matter of time before saws get it. Steve

 

[sachsmo]

Will be interesting to see what comes around.

You young guns can play and pay for that.

 

[Chris-PA]

OK - could we avoid brand bashing or pining for the simpler days of yore? While I am an engineer designing electronics, I am actually no fan of overcomplication or gratuitous technology. Also, I quite like Echos and Makitas and don't think absolute minimum weight and max horsepower are the only measures of a good saw. However, without some major change the 2-stroke is dead because people are not going to put up with the pollution and fuel waste from its inherent design deficiencies. And part of that reputation for pollution is actually the defective "carburetors" that they used for so long, but no matter the damage is done. These systems are being introduced in a desperate attempt to meet the regs and companies that don't have them will likely be out of the US market.

What I wanted to figure out was who owns them, who has to pay royalties and who is out in the cold? Also if there were some other alternatives to strato and feedback carbs coming down the line. Companies will often put a lot of R&D in rather than spending money on royalties to a competitor - sometimes this is for good stuff and sometimes it ends up just being half-assed workarounds (which is what SLR looks like to me, but maybe not).

Maybe crankcase injection has some advantage over a feedback carb, although I don't see it, but it would be mechanically more complicated. You could try to time the injection pulses for late in the scavenge part of the cycle to get a strato-like effect I guess, and it might get Stihl around Husky's patents - but likely at a higher cost. And just because they do direct cylinder injection on mounted engines does not translate into hand-held tools.

So it looks like strato and feedback carbs for the foreseeable future - these really are major advances, and Husky owns them both. Maybe crankcase injection eventually but I wouldn't hold my breath for direct cylinder injection. SLR will probably go nowhere.

 

[Tree Sling'r]

When I mod my first 4 stroke, I will want it to be 2 stroking when tuned properly, haha. Oh, jeez, that begs another question...What oil to use??? Lol!!!

 

[one.man.band]

Interesting, I didn't realize Echo was going with strato. We'll see how 4-strokes work out for chainsaws.

I still haven't figured out what I think of that SLR thing, though I've read the explanation a few times. Seems like they have to match the volume of that chamber to the volume of the cylinder, but I'm not sure if it requires any resonance tuning. It kinda looks like it would, but if so then it would only really work at one rpm. I would assume opening up the muffler would defeat it completely.

adding around 4 oz. of extra steel to make a muffler with dual chambers:
-reducing scavenging losses (i.e. unburned fuel vapor exiting muffler) by 15%
-reducing emissions without the use of catalytic converter
-reduction of fuel consumption by up to 40%

all by adding about 4 oz. of extra steel.

seems like they out-thought the big guys by a touch. and thier system never clogs like a cat that is rated for about 50 hours on the big guys saws.

 

[sachsmo]

adding around 4 oz. of extra steel to make a muffler with dual chambers:
-reducing scavenging losses (i.e. unburned fuel vapor exiting muffler) by 15%
-reducing emissions without the use of catalytic converter
-reduction of fuel consumption by up to 40%

all by adding about 4 oz. of extra steel.

seems like they out-thought the big guys by a touch. and thier system never clogs like a cat that is rated for about 50 hours on the big guys saws.

So are you saying the SLR works?

 

[Joe Kidd]

Is this the future of saws? Oil-less technology? The only lube required is elbow grease!
View attachment 267919

 

[Chris-PA]

adding around 4 oz. of extra steel to make a muffler with dual chambers:
-reducing scavenging losses (i.e. unburned fuel vapor exiting muffler) by 15%
-reducing emissions without the use of catalytic converter
-reduction of fuel consumption by up to 40%

all by adding about 4 oz. of extra steel.

seems like they out-thought the big guys by a touch. and thier system never clogs like a cat that is rated for about 50 hours on the big guys saws.

Yes, but......

The thing works by having a chamber in the muffler that fills with exhaust during the scavenge period so that there is too much backpressure for the fuel/air mixture to get out the port. Then once the exhaust port closes this accumulated exhaust must exit out of the chamber through the restricted outlet before the port opens again. There must be some kind of pulse tuning involved and the shape must be important, otherwise the chamber would fill with stagnant/unmoving gasses and it would just look like a muffler with a teeny outlet. It cannot help but have a lot of backpressure. I'll agree it's cheap.

Do they need to use a cat with strato and feedback carbs?

 

[one.man.band]

So are you saying the SLR works?

that's what dolmar's description says.

just think it's quite an achievement for minimum extra production cost.

-omb

what they have the added helmholtz resonator tuned to would be interesting to know.

-OMB

 

[sachsmo]

that's what dolmar's description says.

just think it's quite an achievement for minimum extra production cost.

-omb

what they have the added helmholtz resonator tuned to would be interesting to know.

-OMB

Perhaps there are still secrets of Physics that are yet to be realized eh?

 

[stihl023/5]

oh, you guys.

If you bought a car in 1940, it might have a total lifespan of 200K miles if you were lucky, and in that time it would have needed countless timing adjustmets, carb adjustments. Heck, it probably have had the heads off at least twice to make it that long and maybe even bottom end work. Not to mention rotting hoses, belts and other assorted junk.

Nowadays, you buy a new vehicle and they last 300K+ without ever needing anything adjusted. Stuff still wears out and breaks, but man the reliability is a billion times better even though it is a drastically more complicated machine.

You are not talking about the so called big three.otstir:

 

[one.man.band]

Perhaps there are still secrets of Physics that are yet to be realized eh?

i've been told that "i'm full of it".

-omb

never heard of that other thread.

 

[CATDIESEL]

As I understand it, it is very simple - Stihl is paying Husky to use the first generation Strato and AutoTune technology, but aren't allowed to use the second generation of either.

you have been saying this for a while now, do you have proof of this????? i am not saying it is or is not true. it is funny how stihl is supposidly using the first gen. autotune and it works perfectly, and the latest and greatest AT has its share of issues. you do not have to read here much to see it either, with the exception of Sunfish' AT saws , his has had zero issues ever. again i am not saying it is/is not true, just wondering where the proof is. the new stihl fuel injection is light years ahead of m-tronic or autotune, did husky design that too????????

 

[Chris-PA]

Is this the future of saws? Oil-less technology? The only lube required is elbow grease!
View attachment 267919

Actually, yes. But not the real near future as long as you can afford the fuel.

 

[Hedgerow]

that's what dolmar's description says.

just think it's quite an achievement for minimum extra production cost.

-omb

what they have the added helmholtz resonator tuned to would be interesting to know.

-OMB

And for those of us that can't leave things alone, a simple muffler removal and hollowing, gets the 7910 back to the power we've become accustomed to in the 7900...
And keeps the platform around for a bit longer...

 

[Hedgerow]

you have been saying this for a while now, do you have proof of this????? i am not saying it is or is not true. it is funny how stihl is supposidly using the first gen. autotune and it works perfectly, and the latest and greatest AT has its share of issues. you do not have to read here much to see it either, with the exception of Sunfish' AT saws , his has had zero issues ever. again i am not saying it is/is not true, just wondering where the proof is. the new stihl fuel injection is light years ahead of m-tronic or autotune, did husky design that too????????

There's a 562xp in my shop that has had zero issues also...
And a brand new Echo CS600p... That ones just a strato... But a very well made machine.
Limiters have been removed already... "and it needed it"

 

[one.man.band]

And for those of us that can't leave things alone, a simple muffler removal and hollowing, gets the 7910 back to the power we've become accustomed to in the 7900...
And keeps the platform around for a bit longer...

if the 7910 has SLR it seems to be pretty strong, the way it is.

Geprfte Motorsgen

-OMB

 

[zogger]

adding around 4 oz. of extra steel to make a muffler with dual chambers:
-reducing scavenging losses (i.e. unburned fuel vapor exiting muffler) by 15%
-reducing emissions without the use of catalytic converter
-reduction of fuel consumption by up to 40%

all by adding about 4 oz. of extra steel.

seems like they out-thought the big guys by a touch. and thier system never clogs like a cat that is rated for about 50 hours on the big guys saws.

They have some sort of modest variable ignition timing as well now.