How many hours to expect out of a chainsaw?

[Diesel JD]

I was going to say what you aid, but I'm afraid that one of those tiny tachs would look kind of gay on a chainsaw. Now Joker's post about the diesel saw is pretty cool. I'd like to have one just to say I had a diesel saw, bet it can blow some serious diesel dust. Not for girly men I'm sure!!

 

[Lawn Masters]

the diesel saw, is an Jonsered model, I dont know as much as a few others here do, but I'd like one for me.

 

[Mange]

Like this diesel Jonsered from the 50`s?

Russ

I made a big long detailed reply for this, and forgot what site I was at.
As usual it did not load as usual, so If he wants info on this saw, he can contact me by E-mail.
I would relly like to know the story behind this Jonsered XC.
Third model from J-red, second Diesel, electric powered glowplug.....

 

[Mange]

"Norska Sågblads fabriken" made the Comet that was the first Diesel powered saw, engin parts was made in Jonsereds factory. After this the Jonsereds made their first saw XA, a propane heated glowplug Diesel, as the Comet.
The XB was a petrol saw, but with simular fuel pump as the XA.
then XC, XD, XD Super, XF, XG, XH. the nuber serieis start after this.

But you can disregard all of this as I am as usual off the mark.

 

[Al Smith]

Not to drift off the subject but along the lines of small diesel engines,I saw an interesting example.The engine was 12 HP single cylinder from a trencher.This contraption had a racheting compression release on the exhaust valve and took four complete revolutions to completely close.The theory was that on each revolution the compression heat would build higher and higher as the valve closed more.It worked great but took 4 or 5 cycles of 4 revolutions each to get the thing started.

 

[Lobo]

Having a small diesel for power, the vibrations level on this saw must have been incredibly high !

Must have made one heck of a lot of racket also ! I wonder what the noise levels measured up to.

 

[Mange]

I will try to get the XA I have to run this winter.
If I am lucky I can tell you how it behaves in spring/summer.

 

[mktest]

I had an Audi 100 (5000 model in the US I guess), with the small 1.8l-engine. I "inherited" it from a relative. It hardly used a drop of oil and the engine sounded great even after 270k miles. Then the car had to be retired for reasons unrelated to the engine. I still have the car for parts in my yard, it has been standing in rain and snow and mud for over 2 years and it still starts fine every 2-3 months when I move it a bit so the brakes won't get stuck.

Now I have another Audi 100, with 2.2l-engine (supposedly better), 180k miles, and it's an oiloholic, drinks a litre for every 1500 miles I drive or so

I think modern engines are built of better material, at least in principle. But their tolerances are smaller. I don't expect our new 2152 to last as long, or be as tolerant to lack of maintenace, as our older saws, such as the Jonsered 52e. We're not professionals I can't imagine we run our saw for more than 50 hours a year (bar in wood), it might idle a bit though. Cuts enough wood for heating 3 houses all year.

Many new Mercedes and Audi cars are built to last "forever", properly maintained they will last decades or many 100k miles. Yet they often fail. Why? People put "tractor oil" in them.

I really should try to make shorter and more focused posts.

 

[timberwolf]

Take a 200k mile car engine given an average 50 mph speed for it's life thats 4000 hours.

I doubt any 2 stroke (except a Detroit diesel) would last as long, let alone a chain saw that runs at 10000 plus rpm and is subject to a lot of dirt and tough conditions.

 

[bvaught]

Take a 200k mile car engine given an average 50 mph speed for it's life thats 4000 hours.

I doubt any 2 stroke (except a Detroit diesel) would last as long, let alone a chain saw that runs at 10000 plus rpm and is subject to a lot of dirt and tough conditions.

Finally the voice of reason . I am thinking that pro saws last in the 300 hour range and consumer saws half of that.

 

[spacemule]

Take a 200k mile car engine given an average 50 mph speed for it's life thats 4000 hours.

I doubt any 2 stroke (except a Detroit diesel) would last as long, let alone a chain saw that runs at 10000 plus rpm and is subject to a lot of dirt and tough conditions.

Car engines and chainsaws are obviously not comporable. I will say I think you would be be hard pressed to find a car that's averaged 50 mph over it's lifetime. I would think 25 would be more reaosnable--lot's of city driving, lots of idling time at stop lights, etc.

 

[timberwolf]

what ever, call it 25 mph and you get 8000 hours.

But if you relate it back to rpm it would come about =

4000h @ 50mph x 2500 rpm = 600 million revelutions

or

8000h @ 25 mph x 1500 rpm = 720 million revelutions

Is it a standard or auto trans?

 

[rmihalek]

Okay, no one commented that the chain on the diesel saw appears to be on backwards. Or else, perhaps the diesel runs counterclockwise, but then the bucking spike would need to be on top.

On topic, I consider replacing rings a normal part of two-stroke maintenance. Maybe this is because most of my experience with two strokes is from dirt bikes where you get 10-40 hours on a set of rings. I think the limiting factor in a saw engine would be the main bearings (at the crank shaft/case interface) and the needle bearings at the con-rod/crank interface.

 

[timberwolf]

In terms of metal wear, if metal wear is related to friction and if friction is a square of velocity engine parts turning at 10000 rpm may be subject to much more wear than that of engine parts turning 2500. But it's not that simple, take into account the surface speeds of the internal parts.

The average piston velocity of a 305 chev running through a 3.48 inch stroke @ 2500 rpm is about 1450 fps (2900 fps at 5000 rmp stock redline)

The average piston velocity of an 066 stihl running through a 1.57 inch stroke @ 10000 rpm is about 2600 fps (3650 fps at 14000 rpm max)

square the difference and the friction is a lot higer in a saw, also I doubt a 305 chev spends as much time at the red line as an 066.

Same goes for main bearings although much different designs 2.45 inch diamiter chev vs well less than an inch diameter on saw sized 2 strokes.

 

[Mange]

Okay, no one commented that the chain on the diesel saw appears to be on backwards. Or else, perhaps the diesel runs counterclockwise, but then the bucking spike would need to be on top.

Actually, it is runs upside down.

 

[Mange]

A logger here has the saw for one year and work about about 1800-2200 hrs/year.

There is a few that keep them longer, but not many, it get's too expensive.

 

[Diesel JD]

I bet finding glowplugs for it is fun, or does he just delete the glow plug and give it a squirt of "white death"

 

[Al Smith]

I bet finding glowplugs for it is fun, or does he just delete the glow plug and give it a squirt of "white death"

A diesel will "light off"[old navy term] pretty easy with just a source of heat in the intake .I've started a diesel 555 Ford backhoe,many times at o degrees F with an acetylene torch forcing heat in the intake.They do blow white smoke for a while,at that temperature.
As to the length of hours on a saw engine,I have no idea.I think an old McCulloch will run forever[not really].I have some oldies but have no idea how many hours are on them.
I do have an old PM 610 that cut 3 to 4 full cords per week,3 to 4 months per year for 8 years.It looks a bit rough but still runs like a new one.
If you really want to split hairs,just because you are working,say 5 or 6 hours in the woods doesn't mean the saw is running that length of time.More likely a third or less of that time.

 

[Chainsaw Master]

And about 2000 hours a year with a 40hr work week. If pro's feel they need new saws each year, then 1500 hours sounds about right (the saw isn't run 8 hours a day).

after logging for 20 yrs, my thought is about the same, altho I've seen some saws last for a couple yrs of hard work, while others died after a couple months.

 

[Marco]

It really come down to when you feel like saying "ah to hell with it" and go by a new one. It's not a horse you don't have to shoot it when it breaks, you can keep picking up the pieces until you don't care to deal with it any more.