4 stroke chainsaws?

[Ianab]

I don't think engine RPM is going to be a problem.

I agree.

My Toyota Corolla revs to 8,000 rpm (factory standard) - same as my Stihl 090. 

Be some interesting challanges about weight and cost ( more moving parts isn't going to make them cheaper ). But there is nothing inherently impossible about making a 4 stroke chainsaw so I'm guessing they will appear in due course.

Ian

[rahtreelimbs]

I like new technology!

I would like to see what can be built in a 4 stroke chainsaw.

I am not giving up my 2 stroke saws anytime soon!


Just want to see want can be done!

[Deadwood]

There will be challenges ahead for sure. One thing I failed to mention was how on my four stroke sled the motor is 973 cc's in order for it to compete with other 2 stroke sleds in the 600 cc class range.

I was reminded of this yesterday when a friend dropped by to look at my new sled. When he remarked how foolish it was for Yamaha not to put on a recoil I was reminded of this cc diference. Yamaha did not make a mistake, there is just no way the average person can pull start a 973 cc 4 stroke motor when it is 20 below.

Now all along I have compared 2 stroke sleds to 4 stroke sleds because this is an area that has always been ruled by 2 stroke powed. No doubt a 120 hp snowmobile is going to be different than a chainsaw. Still I see weight as the biggest issue to chainsaws. Like you I am interested to see what the engineers come up with. Heck maybe they will surprise us all and come out with a nuclear powered chainsaw?!!!

[Dan_Shade]

if we had a saw that "never"ran out of fuel, how would we know when to touch up the chain! 

[IndyIan]

Well, I'm not sure 4 stroke saws are too far off...  I don't really know if thats a good thing as they would be alot more complex/$$$ but they should run with less pollution. 

One thing going for 4 strokes is that 2 stroke chainsaws don't have room for a proper tuned exhaust so they are at a big disadvantage compared to sleds or dirtbikes.  So now the potential output of 70cc 2stroke or 4 stroke saw is closer compared to a 2stroke or 4stoke 250cc dirtbike.

I have read than evinrude has 2 stroke boat motors that get better mileage than 4 strokes so maybe the 2 stroke can overcome that advantage too.

Ian

[Deadwood]

Again, I have to refer back to sleds because this is what I know best, and has the greatest 2 stroke versus 4 stroke battle that I know of. I think you are right though about fuel economy. Two stroke snowmobiles are getting about the same miles per gallon as 4 strokes. I think mine gets about one or two miles more per mile than my friends equivilent 2 stroke. I think the emission manadates levels out the playing field. If you are required to reach a certain emissions number, it's just common sense that burning the same amount of fuel will get you in the same ball park.

[Ianab]

If you are required to reach a certain emissions number, it's just common sense that burning the same amount of fuel will get you in the same ball park.

Not completely true...
Part of the emission standards is WHAT is being emmitted.
The 4 strokes will normally burn fuel cleaner, where a 2 stroke has a tendancy to spit out a bit of unburnt fuel / oil mix. The unburnt hydrocarbons contribute more to smog than the Co2 / H2o of fully burnt fuel. Yes the amount of fuel used is the same, but that 2 stroke 'smoke' is a greater pollutant.

Ian

[Rocky_J]

I've read that one 747 jet plane will burn more fuel in one cross-country trip than all the chainsaws in the United States will burn in one year.

Emissions requirements are a joke. They are a means to an end devised by wacko greenies to deprive the rest of us from the modern marvels of our time.

[pallis]

I wholeheartedly agree with Rocky-J.  Yes, 2 cycle chainsaws put out more pollutants and hydrocarbons than the V6 in my S10, but in real terms, the actual effect on our environment, it's infinitesimally insignificant.  The exception might be something like peak use in cities during prolonged periods without wind.  If you find yourselves in that situation, grab your 4 cycles, and pray for a breeze.

[blueox]

I don't know a thing about Chainsaws ...but what I do know is that I LOVE to snowmobile. A couple years ago my husband surprised me with a beautiful BLUE (saphire blue) V-1000 Bombardier Grand Touring and she is a 4-stroke!! I love it!

I grew up on the front of my Dads snowmobiles...the carbrator right in my face ( no wonder I could fall asleep so easily on my rides with him....I was drugged!!) My Gem (snowmobile) is smooth...QUIET and no fumes!!! This is my winter Limo! (When I called my Mother-in-law to tell her that I got a new SAPHIRE  for my birthday, she thaught for sure I got a new ring....I'd rather have the sled over a ring anyday!!)

My husband has a 700 Bombardier 2-stroke and he gets 1/2 the gas mileage that I get!!! But one problem we have encountered with mine is that we need to change the battery every year, we were told that this is a common problem with Arctic Cat 4-strokes as well!

Almost time to hit the trails. There is nothing better than working all day...getting bundled up at dark...and riding to the local pub for burgers and fries!!

Laurel

[Deadwood]

Yep, I know what you mean. In fact if you would like to join us, there is quite the snowmobile conversation going on in the Other Outdoor Interest's section of this website.

[Furby]

Here's a thought........
The 4 strokes have a bunch more torque, but less speed right.
Would a more agressive chain be better suited to a 4 stroke to help keep the cutting speeds balanced?
I mean, if you redesign a saw so that it is a 4 stroke, why wouldn't you redesign a chain to match the saw?

[ElectricAl]

I talked to a Stihl road rep at a small show today. I asked about Stihl's progress on a 4 stroke Chain saw.

His answer was, "Stihl will not develope a 4 stroke as long as they can meet EPA standards by using Catalytic Converters on 2 stroke saws"

[james]

any body for a wankel rotary i hav a friend who built a mazda rx-7 that would turn 20,000+
james

[Deadwood]

You make a good point Furby. The point of a chainsaw is to make a cut in wood that is as fast as possable from point A to Point B. The simplest way to do that is to have high chain speeds, but it is possable to increase the amount of wood taken per tooth so that wood removed would be higher to match the available torque of the 4 stroke engine.

[leweee]

They all ready make 4 stroke saws with special chain.

Check it out  http://www.forestryforum.com/board/index.php?topic=9639.0

They just ain't practical for everyone

New Link....http://www.killsometime.com/video/video.asp?ID=297

[Ianab]

any body for a wankel rotary

Been done already by Dolmar.
Never caught on, but maybe with the better technology that Mazda have developed with the rotary engines now it could work..



Cheers

Ian