Spuds Porting and Tuning Thread

[spudulike]

Next one up, Stihls big thumper, an 088 with a dodgy oiler and in for porting. First 088 I have done but have done an 084 many years ago.

Should be interesting!

[wicklamulla]

21 hours ago, spudulike said:

Next one up, Stihls big thumper, an 088 with a dodgy oiler and in for porting. First 088 I have done but have done an 084 many years ago.

Should be interesting!

Yule be doin an 084 again soon enuf! 

[wicklamulla]

On 03/02/2018 at 19:28, Andrew McEwan said:

The modest Mr Spud strikes again, obviously not in the same league to what he'd prefer to be working on!, but these two have gone from being very average but handy little weiners to total mini rippers. Cheers Steve!

 

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

[Joe Newton]

 you ported and 2511s yet Steve? I'll be boxing mine up for you this week. 

[john p]

 you ported and 2511s yet Steve? I'll be boxing mine up for you this week. 

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

[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!