.325 vs. .375 on a ported 50 cc saw. Which is better?

[wendell]

This question was brought up in a couple threads so I tried my best to do some testing this weekend at the Iowa GTG. Big thanks to mweba, GPT and pele55 for their invaluable help! Also, a big shout out to WGP for donating his 3/8's sprocket so we could complete the test since my local Stihl/Husky dealer seems not to know what size sprocket goes on a 346.

We did the testing on a piece of walnut with LPX chain. The .325 was run on a 16" bar (chain was almost new with 1 sharpening which those in attendance on Friday can attest I took a lot of time to make sure I got it right). The 3/8's chain was fresh out of the box and run on an 18" bar.

(videos may not match the posted times as I did a couple runs each to get the best time I could)

.325 7 pin 9.93 seconds

[video=youtube;CpNlF7SBgLA]http://www.youtube.com/watch?v=CpNlF7SBgLA&feature=uploademail[/video]

.325 8 pin 9.60 seconds

[video=youtube;H9Q6ggtO6Qk]http://www.youtube.com/watch?v=H9Q6ggtO6Qk&feature=uploademail[/video]

3/8's 7 pin 8.93 on second run

[video=youtube;jlbQRtjzXE4]http://www.youtube.com/watch?v=jlbQRtjzXE4&feature=channel_video_title[/video]

I also did a third run on the 3/8's where I really leaned on it that did not get recorded but I was told after that it ran an 8.50.

I think I might even be able to run an 8 pin with that result.

 

[blsnelling]

We did the same testing with the same model saw, and came up with different results. That's why it's always best to try your saw, in your wood, with your chain. BTW, neither vid with the .325 shows a proper load being put on the saw. You will not get the fastest cut time unless you put a good load on it, just as you found with the 8.50 cut using 3/8.

 

[wendell]

Maybe it would be beneficial to you if you read the disclaimer before posting.

 

[blsnelling]

Maybe it would be beneficial to you if you read the disclaimer before posting.

What did I miss?

 

[Art Vandelay]

Maybe it would be beneficial to you if you read the disclaimer before posting.

Settle down cheese head.

 

[komatsuvarna]

What did I miss?

That the videos may not match the posted times.


Im really liking the 3/8s on my 346.

 

[lambs]

I would be interested in hearing some discussion on using 3/8 chain on 50 cc class saws. I bought a 261 last week from a local dealer and asked about using 3/8, and he advised against it. The saw came with a .325 16" bar and it was a demo saw with a couple hours run time on it according to the dealer. I haven't put it into anything challenging yet, but this saw really screams with that set up.

I went to a different dealer for my annual purchase of 1/2 price Stihl chain, and asked them about it too. They said they had actually converted a few 261's to 3/8 for some of the local pros, and a few of them suffered broken crankshafts. Needless to say, he strongly advised against it on the 261.

Has anyone heard of any issues with broken cranks on the 261?

 

[blsnelling]

I have my preferences on 3/8 vs .325 on 50cc saws, but no way is 3/8 chain responsible for a broken crankshaft! Try it for yourself and run which ever one you like.

 

[wigglesworth]

3/8 all the way!!!


WOOT WOOT!!!

 

[wyk]

My mildly ported 50cc Echo pulls a 325 with authority in hardwoods on a 20" bar. Here it is in Sycamore from a stump I cut with my 385xp:

<iframe width="560" height="315" src="http://www.youtube.com/embed/hIayM4Ol0eQ" frameborder="0" allowfullscreen></iframe>

 

[procarbine2k1]

Thanks for taking the time to post this up ol' buddy, and everybody that contributed to the test. Good to hear the positive results with the 3/8, Ive been kicking the idea around on the 260... just havent got around to it yet.

 

[blsnelling]

In the testing we did, the 3/8 hurt the 260 more than it did the 346. But then again, you have to try it for yourself and see what you like.

 

[Mastermind]

In the testing we did, the 3/8 hurt the 260 more than it did the 346. But then again, you have to try it for yourself and see what you like.

My 026 likes .325

I really appreciate the positive messages I've received about the 346 I did for wendell. It was a pleasure doing a saw for him, he sent a nice clean saw and all new parts for the build.

Oh yeah. I love the 346xp........... :msp_thumbup:

 

[Officer's Match]

In the testing we did, the 3/8 hurt the 260 more than it did the 346. But then again, you have to try it for yourself and see what you like.

Like I said in the other (NE346) thread, that Jred of mine you built just rocks with a 3/8 Brad. I had actually planned on picking up a 441 M-Tronic for some of the stuff I'm now cutting, but after this past weekend with the 2153 buried in Ash, Locust and Cherry, I'm not in a big hurry - not that I don't still lust for a 70cc saw.

 

[blsnelling]

Understand that we're splitting straws here guys. Any of these saws will pull 3/8 fine. As we all love to do though, we want to know which one's fastest

 

[Officer's Match]

Understand that we're splitting straws here guys. Any of these saws will pull 3/8 fine. As we all love to do though, we want to know which one's fastest

And there I can't help, only ran 3/8 so far, as it throws chips like a maniac and cooks up 18" thick cookies like Rosanne Barr's chef.

 

[mactodd]

Were the rakers set at the same depth? I'd imagine you could go .005 deeper with the .325 running an 8 pin since it is about the same diameter as a .375 7 pin. Really depends on the cutter design though, as the .325 may not clear chips as well as .375. I'm interested in the experiments though, as I am going to put .325 RMC on a 5-10 mac with a 16" bar and 8 pin, and am anxious to know what to expect.

 

[Terry Syd]

Mac, that's my big question about the testing. The cutting angle has a huge influence on how the chain cuts.

What were the cutting angles of the chains? Were they the same? (raker depth isn't informative enough, it is only one side of the triangle that gives rise to the trigometric function of cutting angle)

A interesting test would be to increased the cutting angles of each chain, incrementally, to see if the .325 vs .375 results remain constant throughout an increase in cutting angle.

Edit: Here is a great thread by BobL on cutting angles - http://www.arboristsite.com/chainsaw/114624.htm

 

[Stihlman441]

I went with 3/8 .063 on my 261 for afew reasons,its just easyer to make a loop of chain of the roll that all my other saws run,same sharpening file ect.
My 261 has had a muff modd added extra port,allso remembering a 7 pin 3/8 sprocket has a larger dia than a 7 pin .325.
First vid green Sugar gum 18'' bar.
Second vid is dry Peppermint and up against a 260 with muff mod same bar and chain.

[video=youtube;c40EbbuNwlE]http://www.youtube.com/watch?v=c40EbbuNwlE[/video]

[video=youtube;yA3u40KvWWs]http://www.youtube.com/watch?v=yA3u40KvWWs[/video]

 

[wendell]

Being it was the same type of chain with the .325 being only touched up and the 3/8's being OOTB, I would say the angles and rakers were the same. Or at least as close as I would worry about getting them.

If someone wants to take this test to the next level, you are more than welcome to.