The 2025 346xp Porting Thread

[oddsawz]

Credits:

Thread 'Porting The NE346XP'

Aug 10, 2016

Looking for suggestions on porting, #s, tips and tricks on porting the 346!! Saw will be used with 16" Cannon LP bar with PS chain and used to cut up to 16" wood. Thanks guys

• Keith Gandy
• Replies: 318
• Forum: Chainsaws

• 

Thread 'First port and question about timing for 346xp cylinder'

Dec 16, 2021

Trying my hand at bringing a dead 350 to life. I’ve read about everything I can get my hands on about porting these 350,346,353’s.
I fell for the slick marketing of the Hyway titanikel cylinder (this one was advertised as a 353 kit) and the “pop up” piston.

I have read quite a few threads by MATTYO, MasterMind and TreeMonkey and all seem to run similar numbers for the 346xp, or 350 to 346.
my question is in regards to setting up port timing and the transfers on this saw. I worked the bearing cup to get .023 squish and my timing numbers currently are Exhaust 108, Intake 78, and transfers...

• Headhunter1111
• Replies: 70
• Forum: Chainsaws

• 

Masterminded 346XP Tips And Tricks

Here's a few little things we do on the 346XP..... No closeups of the port work.......we've seen too much of that stuff already. Just remember......no popups were harmed in the porting of these three cylinders. :)

www.arboristsite.com

Mastermind Revisits The 346XP

I've done so many 346XPs that I don't think about doing a thread on them when they come through. I thought I might share my version of the 346XP build. Now keep in mind that everyone has their own ideas about what makes a great running 346XP.......just because I might do something a bit...

www.arboristsite.com

After repairing saws back to stock for 8 years I decided to offer up services to a couple of tree service friends. It became clear that they wanted a bit more out of their saws so I started the porting journey.

First up I had a go at a 346xp. I’ve had a personal one for several years and it always blew me away. I had never run anything with work done.

Got some good info from a lot of threads on here and from various YouTubers. I just didn’t want to bump the old threads I was hoping everyone could share their experience in a newer thread for those late to the 346 party

I have just finished the build and here is what has been done:

-Machined squish band and base 0.050
-Matched cylinder to crankcase
-Widened exhaust port piston side
-Matched exhaust to gasket, muffler side
-Smoothed entry on lower transfers
-Knife edged lower transfer divider
-plugged decomp hole

Exhaust port vs stock

Final numbers:
0.019 squish
105 exhaust
125 transfer - 20 blow down
78 intake

Other parts:
346xp intake boot
357/359 carb mount
HDA 199 carb
357/359 air filter/elbow
Cylinder cover without primer hole



Modifications:
-Opened up carb base floor to fit 357/359 switches.
-Ground a few mm from crankcase where intake partition sits.
-Gutted fuel vent in tank, but ended up using an echo style vent on the end of the vent hose
-Muffler mod, used a dukes wide deflector




It runs and screams but I haven’t really got to test it yet because of the heat. I made three cookie cuts so far and it feels pretty strong. Hoping to get some video soon and put it up against another stock 346xp for comparison.

I have a few more to work on and would maybe like to decrease the blowdown on the next one.

All feedback/advice/hate is appreciated

 

[oddsawz]

Got a few more to work on too

 

[huskihl]

I’d try a lower exhaust and much higher transfers

 

[huskihl]

Stock vs xs ported. Both have 357 carb

 

[Hall84]

Stock vs xs ported. Both have 357 carb

I’d say, that’s proof in the pudding.

 

[farminkarman]

Stock vs xs ported. Both have 357 carb

How about that comparison you did of a sausaged 346 and a stock 572?

 

[farminkarman]

I’d try a lower exhaust and much higher transfers

I definitely prefer this kind of build ^^^

 

[oddsawz]

I took a look at my notes again and I actually have the transfers at 125 - edited original post.

 

[huskihl]

How about that comparison you did of a sausaged 346 and a stock 572?

 

[Duane(Pa)]

I like the 346! Subbing into this thread...