Dolmar 421 vs echo 490

[SawTroll]

View attachment 28777

Gotta agree with Corey here , this saw was designed as simondo says for the semi pro user - farmers saw with a open port engine which means more torque and less top end its got six ports which help scavenging and new fuel backing up the chassis on this saw is massive with large transfers which aren't as well designed as other pro models So you ain't gonna get a wild top end with large transfers and a smaller displacement but with some good lathe work miricales happen i haven't tried a gasket delete it probably wouldn't work as well as other saws
But I can't leave my 420 at home it's always in the truck it's a great saw stock or ported

Here's a pic of the 420 cylinder from my saw not great quality

Open ports usually doesn't mean more torque anywhere in the useful rpm range, but usually brings the max performance lower in the rpm range, and making the difference in performance between high and lower rpm feel smaller. This often is the case with close port designs that aren't really good as well.

Of course this isn't totally "black and white" - as there are more or less bad close port designs, and some very good open port ones out there.

 

[ajschainsaws]

Yes the 42 special is a good example of this

 

[Red97]

How did the 590 and 670 turn out @Red97?

Don't know. Saws still sitting on the bench.

Haven't touched a saw since april.

Once the temp drops to the 40's cad will probably kick in lol.

 

[KenJax Tree]

Hooray, Joe!!!

 

[exSW]

Don't know. Saws still sitting on the bench.

Haven't touched a saw since april.

Once the temp drops to the 40's cad will probably kick in lol.

Nice to know I'm not the only one.

 

[Nitehawk55]

It's cooled off now !!

 

[Red97]

It's cooled off now !!

Those saws were both done a couple months ago.

590 is ahead in every way shape form..

Except % of magnesium. 670 wins that category.

Have a couple more 670's yet to do trying to top the 590.

http://opeforum.com/threads/echo-670-build.3790/

http://opeforum.com/threads/someone-getting-an-echo-cs-590-for-x-mas.4110/

 

[CoreyB]

I took the 421 out for awhile this afternoon cleaning some brush crap. man that saw with stihl ps chain is such a go getter. I really like the sound after the MM

 

[CoreyB]

Sense this thread got resurrected I figured I would share a video I did with chain testing on the 421.
I tested 3/ 8 lp Oregon 91vxl and Stihl ps
As well as .325 Oregon brand new txl and it's predecessor 95vpx

 

[SawTroll]

Even the latest Echo saws appall me more the more I learn about them, there are some incredibly clumsy design features even in a relatively new design like the 501SX - like a nut outside the sprocket, and not an e-clip, necessitating the use of a piston stop to change the rim.

Then it is unclear what really is the correct bar mount - but they likely want it that way, to sell more of their own overpriced bars....

 

[Woodpecker]

^^^^^