Author Topic: Echo cs670 Porting for Work  (Read 684 times)

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Offline Cut4fun .

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Re: Echo cs670 Porting for Work
« Reply #10 on: January 16, 2015, 10:47:37 pm »
   Here are the measurements of the stock Echo piston:

   Pin boss width    17mm     .667"
   Pin diameter        12mm    .472"
   Comp height         22.2m    .871"
   Total ht.                40.4mm  1.586"
   Dome ht.             2.29mm    .090"

Good deal.

Here is what I found on meteor 268 piston. I dont know which one though.

Meteor Piston Assembly 50mm for Husqvarna 266, 268 Jonsered 670 Chainsaws Replaces 501 65 88 03

Bore 49.96mm
Height 40.5mm
Head Type Flat
Piston Pin 12mm x 33mm x 8mm
Ring 50mm x 1.5mm (Caber F-Cast GH.F)
Compression/Pin Top to top of Piston 18mm
Compression/Pin Center to top of Piston 24mm

Offline aclarke

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Re: Echo cs670 Porting for Work
« Reply #11 on: January 17, 2015, 10:15:50 am »
Good info thk

Offline awol

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Re: Echo cs670 Porting for Work
« Reply #12 on: January 17, 2015, 12:38:52 pm »
   That is real good info, thanks.
   There may be other pistons that would work better for increasing transfer flow, but this 268 sure was fast and easy to fit. The limiting factor on getting more performance from this saw, now seems to be the small intake tract. I did go back in to the jug and adjust some ports with that in mind, and here are the results:

https://www.youtube.com/watch?v=4X3ogrtSAUg&feature=youtube_gdata_player
New ported Husqvarna and Jonsered saws. Woods porting of saws by appointment.

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Offline 660magnum

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Re: Echo cs670 Porting for Work
« Reply #13 on: January 17, 2015, 12:59:11 pm »
The saw overall cuts very good.

The engine seems to be leaning out as it gets some heat into it?

I would start out a little richer so when the heat built up, it was still rich enough?
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Offline awol

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Re: Echo cs670 Porting for Work
« Reply #14 on: January 17, 2015, 03:05:22 pm »
   Yes, you'r right. The latest video was in "racing" tune, right on the ragged edge. No way would I take it to the woods like that, it has better low end with a working tune.
New ported Husqvarna and Jonsered saws. Woods porting of saws by appointment.

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Offline aclarke

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Re: Echo cs670 Porting for Work
« Reply #15 on: January 17, 2015, 04:07:07 pm »
Bigger the ports get, the lower the velocity.  Be careful going to big, will make for poor low rpm power

Offline Cut4fun .

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Re: Echo cs670 Porting for Work
« Reply #16 on: January 17, 2015, 04:21:47 pm »
What air filter set up you have on that one?  I wish mine had the mesh, but mine has the round $30 air filter like a HD.

Offline awol

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Re: Echo cs670 Porting for Work
« Reply #17 on: January 17, 2015, 04:51:19 pm »
   This saw also has the round, pleated paper style filter. I did try running it without the filter and cover, but it made very little difference. This saw has very good low end power with a good tune, so I don't think I made the upper transfers to big. It is however running best with almost 180 of intake duration, and quite a lot of blow down to keep the case compression up, and try to give the restriction in aspiration plenty of time to catch up. I think a much larger carb and intake would really help, with a little less intake duration. I will post all of the current timing numbers for discussion when I bring my book back to the house.
New ported Husqvarna and Jonsered saws. Woods porting of saws by appointment.

doittheoldway@gmail.com  417-259-0248

Offline awol

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Re: Echo cs670 Porting for Work
« Reply #18 on: January 18, 2015, 10:34:03 am »
   Here are the current numbers for this job, this is where it will stay for now.

   Squish:  .021.     comp:190psi.     BD23       case compression:42

   Ex   102/156
   In    96/168/84
   Tr125/110
New ported Husqvarna and Jonsered saws. Woods porting of saws by appointment.

doittheoldway@gmail.com  417-259-0248

Offline Cut4fun .

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Re: Echo cs670 Porting for Work
« Reply #19 on: January 18, 2015, 02:17:20 pm »
So what do you think of how the echo saws exhaust exits are made?  My 3120 hotsaw used the same idea.

 

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