# Exhaust re-mod for the 3120



## Can8ianTimber (Jun 16, 2010)

Well since Barthaigh got me thinking about muffler mods with his fuel mix thread I thought I would ask for opinions about redirecting the exhaust on my 3120. Here is a picture of the dual exhaust mod done by Walkers saw shop.






Here is another angle





It is kind of hard to see b/c it is still nice and painted in those pics. I really only need to redirect the exhaust from the right hand side (due to the saw orientation when milling but I am wondering if one side is altered then do I need to do both sides? Part of the problem is that it is not strictly a milling saw like Bob's. I also use it for making butt cuts on large logs too and anything else that the 372 with 30" bar can not handle. 

I was thinking about a 90deg bend on the right hand side would not get in the way to much but I would really like it if some of the pros could chime in. I am getting ready to do a bunch more milling so I want to get it right before I start.

Thanks


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## BobL (Jun 16, 2010)

The mod looks really well done and I assume the the modifiers also retuned and reset the carby in some way? If yes I would expect that big saw to perk up noticeably in the cut - how does it perform

Hwoever as you say, laying the saw on its side for milling is going to cause a few problems:
* When milling the top half of logs, the bottom pipe could bounce exhaust off the log back up towards the operator.
* When milling the bottom half of logs the bottom pipe could bounce exhaust off the log back towards the operators feet.
* in both the above cases the top exhaust could blow exhaust out towards the operators hand on the mill.
- ie not good for milling. 

You could add removable pipes to either or both stubs but unless your saw have H-screw adjustment on your carby its going to be PITA to switch between milling and CC.

A gas mask and a thermal suit might be a simpler solution.


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## huskyhank (Jun 16, 2010)

First, sorry for the lame drawings.

I'd add some 45 degree pieces as shown in the bad drawing. They will likely make your saw run a tad richer but I don't think enough to matter. Keep them short.

The extensions might be in the way for normal saw use or the dogs might save them from getting hit. You'll have to mock up something to see. If the extensions do hit when sawing you might put some bigger dogs on the saw to give some room.

I'm real interested in what you come up with because I want to modify my 3120!


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## Nikko (Jun 16, 2010)

Walker did my muffler for my 2100 and I had them do two pipes out one side (starter side) aimed down (when the saw is sitting normally). When milling, the exhaust is pushed up and ahead and when using the saw as a saw (bucking), the exhaust is aimed down - both are completely acceptable. The original "tail pipe" (that basically aimed along the top of the bar) was cut and capped - I've not found a down side to this arrangement.

I had a picture here somewhere.. found it - look close at the muffler, you're looking directly up both pipes. I can take a better one if you need it.


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## huskyhank (Jun 16, 2010)

Nikko said:


> Walker did my muffler for my 2100 and I had them do two pipes out one side (starter side) aimed down (when the saw is sitting normally). When milling, the exhaust is pushed up and ahead and when using the saw as a saw (bucking), the exhaust is aimed down - both are completely acceptable. The original "tail pipe" (that basically aimed along the top of the bar) was cut and capped - I've not found a down side to this arrangement.
> 
> I had a picture here somewhere.. found it - look close at the muffler, you're looking directly up both pipes. I can take a better one if you need it.



That would sure work!
My 2100 has the jungle muffler which has louvers pointing down and to the left. Its about perfect for any use I've put it to. Why they don't make them all that way I don't know. The stock Husky pipes are just STUPID!

Here it is:


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## mtngun (Jun 16, 2010)

The Walker muffler is a nice piece that may be worth a few bucks. 

Instead of modding the Walker, how 'bout making a straight pipe for milling, similar to what BobL has done for his 880 ? Keep the Walker around for crosscutting, or sell it.


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## BobL (Jun 16, 2010)

mtngun said:


> The Walker muffler is a nice piece that may be worth a few bucks.
> 
> Instead of modding the Walker, how 'bout making a straight pipe for milling, similar to what BobL has done for his 880 ? Keep the Walker around for crosscutting, or sell it.



Mine is not a straight pipe - it does still have the original muffler in between the manifold and the pipe. I can still replace the original deflector using the 4 torx screws that hold it in place.


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## Can8ianTimber (Jun 17, 2010)

mtngun said:


> The Walker muffler is a nice piece that may be worth a few bucks.
> 
> Instead of modding the Walker, how 'bout making a straight pipe for milling, similar to what BobL has done for his 880 ? Keep the Walker around for crosscutting, or sell it.



I really like this idea. Looks like a muffler is about $91 on Baileys and then I would have the mod costs as well, A little more than I was wanting to pay. Maybe I can add pipes like this.





I don't think that would get in the way for when I am using it in non milling applications.

So if I did a mod like that would I need to adjust anything else? This may sound pathetic but I have never tuned a saw.


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## huskyhank (Jun 17, 2010)

Those long pipes will change the tuning. I think your saw has a fixed high speed jet so there is no easy way for you to tune it. Have you asked Walker about the exhaust? They might have a good answer.


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## 820wards (Jun 17, 2010)

*Exhaust Flow Direction*

Hank,

Here is a picture of my mill with the exhaust pipe directed out and away from the operator. I know your exhaust is on the front of the saw, but the picture gives you an idea how the exhaust should be blowing away from the operator. My exhaust is 2" inch diameter pipe. I have stainless steel screen rolled up tight inside the pipe that works as a spark arrest and does nothing to deaden the sound.

jerry-


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## BobL (Jun 17, 2010)

Jerry's pipe direction is one of the best available. 

The problem with this design 




is it could melt the wrap bar coating and make the wrap handle hot
The noise will be right in the operators face.
And it prevents the addition of any instrumentation to the wrap handle.

I'd be looking at something like this.


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## Can8ianTimber (Jun 17, 2010)

I just talked to Walkers and their opinion was that the pipes would change the settings but not to signifigantly as long as I did not decrease the size of the exhaust. 

He said typically for Alaska milling aplications they do one big pipe coming out of the center of the muffler and a 90Deg so that it would point in the same direction as you are cutting and away from the operator. He is going to look through his used inventory and see if he has a muffler that he could mod in that way and ship to me. That would be sweet. I will keep you posted.


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## BobL (Jun 17, 2010)

Can8ianTimber said:


> I just talked to Walkers and their opinion was that the pipes would change the settings but not to signifigantly as long as I did not decrease the size of the exhaust.
> 
> He said typically for Alaska milling aplications they do one big pipe coming out of the center of the muffler and a 90Deg so that it would point in the same direction as you are cutting and away from the operator. He is going to look through his used inventory and see if he has a muffler that he could mod in that way and ship to me. That would be sweet. I will keep you posted.



That definitely sounds like a much better arrangement.


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## Nikko (Jun 17, 2010)

Found the other pictures of the muffler Walker did for me. At first it looks like the pipes are aimed towards the handle, but the other pic shows it's not an issue.

As I said up there - I've never once regretted this nor would I do anything different if I had to do it again. This saw is used mostly for milling, but get's the odd use as a "real" saw.. the mod works well regardless.


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## BobL (Jun 18, 2010)

Nikko said:


> Found the other pictures of the muffler Walker did for me. At first it looks like the pipes are aimed towards the handle, but the other pic shows it's not an issue.
> 
> As I said up there - I've never once regretted this nor would I do anything different if I had to do it again. This saw is used mostly for milling, but get's the odd use as a "real" saw.. the mod works well regardless.



Now that does look good.


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## 820wards (Jun 18, 2010)

BobL said:


> Now that does look good.






Zoomies!!!! Yea!

jerry-


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## Can8ianTimber (Jun 18, 2010)

That looks like the perfect location for the pipes. I was cutting a large cedar stump the other day and I almost caught it on fire several times. I was not worried about it b/c it is still raining here but despite the fire hazard it can not be good for the heat to get sent towards the log and right back towards the muffler. 

Anyways Nikko, I really like that location for the exhaust, Did you request that design or did they give you options?


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## Nikko (Jun 18, 2010)

I told them (Walker) what I wanted (exhaust up and away when milling) and that's the design they sent me. The double pipe was their idea. Ironically it's not that loud. OK - it's loud, but not obnoxious and it definitely sounds like a big saw!

they were great to deal with - easy peasy

I need to run a couple more tanks through my 346 and then I'll contact them to see what ideas they have for that one - can't wait


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## BobL (Jun 18, 2010)

Just an aside - that muff design would not work on saws that have their oil caps on that side/end of the saw.


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