Spuds Porting and Tuning Thread

[Joe Newton]

1 minute ago, john p said:

Keep meaning to send mine but can’t bear to part with it for longer than a day!

I know it's going to suck hard spending a week hauling a big boy chainsaw  round the tree. 

[spudulike]

Been on this 088 today, sometimes there isn't a great deal of widening that can be done on the ports but you can gain port size by reshaping the port. Doing this has a similar effect as widening but the port must have a very defined arch shape to begin with and can't be "squared" too much otherwise the rings will snag and smash to top end.

Doing this allows the machine to purge the combustion chamber of exhaust gasses faster and means you can reduce blowdown timing as the pressure in the combustion chamber will fall faster and allow a fresh charge of fuel/air in to the chamber earlier.

Anyway - the first pic is the interesting one with half the port reshaped and the other half being standard - note the extra size of the modified side of the port. The second photo is the finished port.

 

[Rich1911]

So have you left the height of the arch untouched, not gone any further towards the cylinder top. Just removed material either side and made the arch profile shallow less of the curve.

[stihlmadasever]

My 346xp landed today spud,lookin forward to lettin her rip...

Thanks for your hard work mate

[Andrew McEwan]

On 05/02/2018 at 18:20, wicklamulla said:

Andy is that a 360WES? What did ya have done  to them?

Yup 360wes and an old 2700, just muffler mods, some carb work and few repairs. 2700 doesn't feel too far off the bigger saw. Excellent chipper/hedge/cutting your flail free saw!

[Stubby]

4 hours ago, stihlmadasever said:

My 346xp landed today spud,lookin forward to lettin her rip...

Thanks for your hard work mate

Welcome to the club ........

[spudulike]

17 hours ago, Rich1911 said:

So have you left the height of the arch untouched, not gone any further towards the cylinder top. Just removed material either side and made the arch profile shallow less of the curve.

Yes, the port timing has remained standard on this one.

[spudulike]

5 hours ago, stihlmadasever said:

My 346xp landed today spud,lookin forward to lettin her rip...

Thanks for your hard work mate

You will like it, they get pretty leery with porting and must be one of the best saws to get ported.

[Luckyeleven]

Well, in case you aren't yet aware, spud is the man.
He recently 'fixed' my 365 x torq and put up with my nagging doubts when it turned out to be a mere blocked (but clean looking) air filter.

He then worked his sinister magic and gave me back a wild beast of a saw.

Photo below was of the test run, That particular fell really belongs in the 'stunt fell' thread. wish I had taken more to do it justice.

Thats a 24" bar for scale. In fact I prefer this saw to my brand new 576..... 

[spudulike]

Glad you are happy, I could tell that you thought the bad running couldn't be contributed to the oily air filter but there you go. The rest is just....Alchemy