Fuel Injection

[AJLOGGER]

This might be a stupid question but would it be possible to have fuel injection on a saw. If you could think of the performance gains and don't say air injection is the same, that just an air cleaner.

 

[Lakeside53]

It's surely possible, and could have great results, but not really practical yet. In addition to sensors and feedback required to accurately meter gas, you need to pump it at higher pressures - and that all adds up to $$, bulk and weight.


It's moving that way though... a new fuel/ignition system that Stihl is in the process of bringing out January 2007 (first on the MS280) has a microprocessor in the coil and connected to a solenoid in the carb. A separate set of magnets on the flywheel generates power for the processor and solenoid operations (which is why you need the EDT8 tach). The microprocessor reads rpm, and in addition to adjusting timing, also adjusts the mixture 30 times per second for "optimal" mix (power verses the epa) in a wide range of conditions. In other words, it adjusts while you are cutting... It does this by making minute adjustments and watching the resulting rpm increase or decrease. Tricky stuff... and guess what? No H screw... and good luck in messing with the carb and ignition timing.


EDIT : a simple analogy of what is happening is the height of the metering needle arm is being adjusted to suit different conditions.

Interesting approach - one that doesn't require the usual sensors to complete feedback.

Why? EPA.... even current stratocharge designs exceeds EPA requirements in a few years...

Buy your 440's and 372's... It's like 1989 with cars.. computerized injection everywhere, hard to modify anything, but hey, it wasn't so bad...


Hard to believe husky and echo etc aren't working on other or similar ideas. Anyone heard anything?

 

[SmokinDodge]

No H screw... and good luck in messing with the carb and ignition timing.

Interesting approach - one that doesn't require the usual sensors to complete feedback.

Why? EPA.... even current stratocharge designs exceeds EPA requirements in a few years...

Buy your 440's and 372's... It's like 1989 with cars.. computerized injection everywhere, hard to modify anything, but hey, it wasn't so bad....

Yes but there will always be a devote few that will find ways of modifying the stock sytem and eventually have better gains than the old versions. It won't be over night though.

 

[Lakeside53]

Yes but there will always be a devote few that will find ways of modifying the stock sytem and eventually have better gains than the old versions. It won't be over night though.

Just need to get my hands on some lab version of the coils -with exposed connector for the flash ram.. :

And, I predict a big sale (well.... a few hundred to satisfy AS) sets of the "old" flywheels, coils and carbs..

 

[SmokinDodge]

I wouldn't be too quick to discount the new hardware. There will be more potential with it that any combo of the older parts. I've seen it with the cars, then the bikes and now last but not least the diesel trucks. It will take time to figure out HOW to make it run better but it WILL.

 

[bwalker]

Why? EPA.... even current stratocharge designs exceeds EPA requirements in a few years...

I think Redmax and thus Husky have a Strato engine that is comliant all the way out to 2012.

 

[Marco]

it all looks good on paper opcorn: crosscuts and doublebits may develope a strong following

 

[Lakeside53]

I think Redmax and thus Husky have a Strato engine that is comliant all the way out to 2012.

That is only a few years... and new designs take time and need to have a life way beyond 2012. The 441 makes it to 2012 also, but then what? I suspect another motive also - earn credits early... just like they did with the 4 mix engines, and that allows much more flexibility on larger pro models continuing to sell "unadulterated".

 

[Lakeside53]

it all looks good on paper opcorn: crosscuts and doublebits may develope a strong following

O.k., I see the popcorn, but you'll have to explain the crosscut and double bits to me..

 

[jefeVTtreeman]

look what fuel injection did for Harley Davidson now every bike comes with O2 sensors, crap!!!!:deadhorse:

 

[timberwolf]

Were all going to be taking our saws in to have them chipped.

 

[jefeVTtreeman]

soon we will be putting them on dynos with different loads (hard woods, softwoods) tuning them with race tuners and putting on a new set of rhineharts. then K&N will make some new filters, followed by a week in florida to celebrate the whole chainsaw society, maybe they will do one out in Sturgis

 

[Marco]

Lakeside I was just wondering where it will stop, axes and handsaws may become the best option. I'll take a carb anyday over fuel injection, fuel injection is popular because the general population is so dense that it can't grasp the idea of pushing the choke in to eliminate the cloud of smoke.

 

[Lakeside53]

Lakeside I was just wondering where it will stop, axes and handsaws may become the best option. I'll take a carb anyday over fuel injection, fuel injection is popular because the general population is so dense that it can't grasp the idea of pushing the choke in to eliminate the cloud of smoke.

 

[B_Turner]

At what point in time will we know for sure that saws like the 5100 and 7900 are no longer going to be allowed to be sold in the US for emissions reg reasons?

 

[thomas72]

I believe it would be a great idea, when the technology makes it effective in productivity and cost. Just think it would eliminate damage to the top end due to over leaning of fuel as long as their are no air leaks, also it can self adjust the fuel consumption and increase the amount of power the saw needs when cutting different types of wood. Thing about it is you probably would have an on board battery to run a fuel pump to prime the fuel system, but it also may give you more space in the air box to put a battery. I do like a carburetor, but it is time to improve a design that is around a hundred years old.

 

[ShoerFast]

It's surely possible, and could have great results, but not really practical yet. In addition to sensors and feedback required to accurately meter gas, you need to pump it at higher pressures - and that all adds up to $$, bulk and weight.


It's moving that way though... a new fuel/ignition system that Stihl is in the process of bringing out January 2007 (first on the MS280) has a microprocessor in the coil and connected to a solenoid in the carb. A separate set of magnets on the flywheel generates power for the processor and solenoid operations (which is why you need the EDT8 tach). The microprocessor reads rpm, and in addition to adjusting timing, also adjusts the mixture 30 times per second for "optimal" mix (power verses the epa) in a wide range of conditions. In other words, it adjusts while you are cutting... It does this by making minute adjustments and watching the resulting rpm increase or decrease. Tricky stuff... and guess what? No H screw... and good luck in messing with the carb and ignition timing.


EDIT : a simple analogy of what is happening is the height of the metering needle arm is being adjusted to suit different conditions.

Interesting approach - one that doesn't require the usual sensors to complete feedback.

Why? EPA.... even current stratocharge designs exceeds EPA requirements in a few years...

Buy your 440's and 372's... It's like 1989 with cars.. computerized injection everywhere, hard to modify anything, but hey, it wasn't so bad...


Hard to believe husky and echo etc aren't working on other or similar ideas. Anyone heard anything?

Lake

As we could be sure that Stihl knows more then a horse-shoer. It would be easy to build a simple feedback system just by tailoring the P1 that goes into the metering side of a compensating carb.

If an O2 sensor single was split to a "and" or a "nor" at say .7 volts, (0.7 volts may be a good compromise or starting place to epa vs best power) and that split was to take place at every coil dissipation, that would be well over 200x per second.

Set the "H" jetting a little too high ..... (fat or rich) (failure saves a jug)

tapping P1 (air filter air) and add a tap somewhere down stream, like a hose to the inlet boot (that would be less then P1) so that a solenoid would either vent P1 at less then .7 volts, or the partial vacuum of the inlet source at over .7 volts , that would lean the saw out a tad, till it returned to .7 volts.

Reason, if I understand this right?
Just as a dirty air filter leans by lowering the pressure on the metering diaphragm, to match less air, allowing a perporting solenoid to allow venturi pressure to the metering diaphragm, would further lean the saw to match the O2 sensor voltage.

 

[ShoerFast]

At what point in time will we know for sure that saws like the 5100 and 7900 are no longer going to be allowed to be sold in the US for emissions reg reasons?

I think 2012 is the next stage of EPA regs, and then it goes to some wierd ideas, like tonage of CO allowed per manufacture, and a bounch of other strange ideas about how we may not even live till then.

 

[bwalker]

ook what fuel injection did for Harley Davidson now every bike comes with O2 sensors, crap!!!!

Putting FI on a Harley is like trying to put polish on a dog turd. When your done it doesnt look much better and it still stinks.:hmm3grin2orange:

 

[ShoerFast]

Putting FI on a Harley is like trying to put polish on a dog turd. When your done it doesnt look much better and it still stinks.:hmm3grin2orange:

Live to ride, Ride to live.