70.7 cc a Harmonic Miracle?

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Arbonaut

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The best things in cars eventually get phased out for one of two reasons.

1. The engineers actually think they have made a better design, ie. lighter or more advanced materials and/or cheaper to build.

2. The original design was too good, ie. 318 or 360 Dodge small block.

With 70% of the profit being made at a dealership service department and the rest on sales, it seems awash which philosophy the engineers might embrace.

At the risk of firing up the debate scenario, I'm going on a limb with chainsaws and stating they just keep getting better. This is competition-driven and the woodsey breed demands the best.
With chainsaw manufature, one thing hasn't changed. Every major player builds a model with displacement at or very near the 70.7 cc mark. When I bought my 044 Mag as a kid, the dealer said I could expect to cut around 100 cords of hardwood with it then expect a rebuild. I know I've done 400 cords and the saw has been to Helsinki and back, with nothing replaced except new guide bars.
Every material has a harmonic failure point. Picture the opera singer who shatters a glass with her voice. What's the chance that the longevity of the saws in this class can be contributed to a synergistic relationship of the components being engineered to operate outside the limits of the harmonic failure point?


Disclaimer: I used to get my thumbs broke playing football, and never learned to type. The cheerleaders did it for me. I was cutting and pasting some stuff on this post and got some major malfunction. It got posted before the words were even put in order. When I retrieved it and realized what was happening, it already had a life of its own. I decided the last couple of lines was a work of art, raw unintended and without the slightest revision. So here it is for posterity. Thanks.

Yours Truly,
Gary Funkatia-- Making engineers scratch their head since 1971.

P.S. WoodHeatWarrior, please go away. And Take 3000 feet per second with you.
 
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Shouldn't need a rebuild after 100 cords. Proper fuel mix and clean intake filters, and saws can last 1000 cords before a rebuild.

Harmonics have little to do with displacement. 70cc saws have some of the best power to weight ratios, and they can cut the largest trees in most areas without need for a bigger saw.

I don't think chainsaws keep getting better. Many argue that the 044 was a better saw than the 440.
 
Silliness. Up until the manufacturers were forced to develop strato engines their development was stagnent. All chainsaws designs had converged on the same basic achitecture and the products were commoditized - they were all pretty much the same, differing only in detail, just like all the basically identical cast iron pushrod V8's the us auto industry cranked out. With the design stabilized then you're optimizing materials, reducing costs, etc. If there's anything special about a 70cc saw, it would be that they can charge more for it than smaller saws and therefore spend a bit more on materials (although mostly it's profit). The cost to them to make an engine has very little to do with displacement.
 
Tune Up

Ok, I've also gone through a dozen sprockets. I stay on top the filters. The original air filter is like new. You'd think I woulda needed an elasto start but the saw starts on the first pull. I run NGK instead of Bosch, too and replace them to stay optimum.
I think the vibration is what induces harmonics and this was thought of and worked out in a German or Scandinavian lab. I didn't mean that displacement alone was related to harmonics.
By the way, Ray thanks for the reputation upgrade.
 
The best things in cars eventually get phased out for one of two reasons.

1. The engineers actually think they have made a better design, ie. lighter or more advanced materials and/or cheaper to build.

2. The original design was too good, ie. 318 or 360 Dodge small block.

With 70% of the profit being made at a dealership service department and the rest on sales, it seems awash which philosophy the engineers might embrace.

At the risk of firing up the debate scenario, I'm going on a limb with chainsaws and stating they just keep getting better. This is competition-driven and the woodsey breed demands the best.
With chainsaw manufature, one thing hasn't changed. Every major player builds a model with displacement at or very near the 70.7 cc mark. When I bought my 044 Mag as a kid, the dealer said I could expect to cut around 100 cords of hardwood with it then expect a rebuild. I know I've done 400 cords and the saw has been to Helsinki and back, with nothing replaced except new guide bars.
Every material has a harmonic failure point. Picture the opera singer who shatters a glass with her voice. What's the chance that the longevity of the saws in this class can be contributed to a synergistic relationship of the components being engineered to operate outside the limits of the harmonic failure point?



What kind of meds are you on. Do you stay awake at night thinking about this. Just curious. I see you posting all over the place about things that make no sense to me.
 
The vibrations associated with a single cylinder reciprocating engine have been understood for a very long time. It's long ago settled science and there isn't anything the Germans or Scandinavians can add at this point.
 
Are talking about mods affecting the engineered harmonic limits of the rorating assembly and other parts of the saw?
 
You're zeroing in on it but my saws don't get modified beyond custom bumper spikes.

After time harmonics causes weak spots in key areas w/ could cause fairures? After extended heavy use/ and/ or poor maintence I could see this as a possablity.
 
...
Every material has a harmonic failure point. Picture the opera singer who shatters a glass with her voice. What's the chance that the longevity of the saws in this class can be contributed to a synergistic relationship of the components being engineered to operate outside the limits of the harmonic failure point?

I'm an engineer and I don't know what this means.
 
To the OP ( who sent me a private message ) You are right maybe I was a little harsh in stating what I really think and I apologize. In the future I will have to look who the poster is so that I can avoid reading things that I do not find useful.
 
I'm an engineer and I don't know what this means.

Me too, nor do I understand how the 318 Chrysler wedge-chamber v-8 can be called optimum. Most certainly not compared to multi-valve pent-roof chamber engines. Too much silly pseudo-technical drooling, OP.
 
A little harmonic balance....

[video=youtube_share;w76ybV0OpnM]http://youtu.be/w76ybV0OpnM[/video]

318 or 360? What about the 340 wedge? The 340 produced far more horsepower than either the 318 or 360 and I would venture that the original 273 was less of a dog too.
 
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Woodcutter TV. Get away from the computor and TV on Friday night. Go out with your friends and find a nice girlfriend. That stuff is backing up on you and poison for your brain.

Don't own a TV. Wife have a cow if I got a girlfriend. Been goin' thru my taxes for my business at night. I'll tell you like Edison told Tesla. It's too bad if you can't understand American humor.
 
I should have said before now, part of the original post got sent off the page, I used my history button and tried to revise it, and it already posted. By the time I retrieved it, people were already responding so I left it. The last few lines didn't get revised a bit. Not what I meant to say, really besides the part about the small block Dodge. I'm still havin' fun though.
 
Don't own a TV. Wife have a cow if I got a girlfriend. Been goin' thru my taxes for my business at night. I'll tell you like Edison told Tesla. It's too bad if you can't understand American humor.

Tesla was concentrating on electricity and not humor. That is why we have AC current. Edison wanted DC for house use and it would not transmit over the lines well. He made a passable phonograph though.
 
Oh, it's so nice to know the 404 diesel in my 4020 is EMP safe, not sure about a modern rev limited CS though. I think a lean runnin EPA saw with a dirty air filter is more of a worry than the harmonic failure factor. The 084 has such a strong connecting rod it can create hormonic problems for the crankshaft at high rpms.
 

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