Spuds Porting and Tuning Thread

[spudulike]

I have been porting a 372XP recently and had some interesting figures from the exercise. The saw was already wearing a jungle muffler which is basically an oversized 346XP exhaust so a large outlet on top and no internal baffle.

 

The saw, before any porting and wearing the performance muffler the saw gave cutting figures of between 13.36 and 14.48 seconds. After porting, using the same bar and chain the saw gave 11.10 to 11.48 seconds.

 

If you take the two best cuts pre and post porting, the improvement is 16.8% if you take the two worst figures pre and post, you get 20.56% improvement and if you take an average then you get 19% improvement.

 

The 372XP is a good machine to port and it shows that you gain 16-20% from JUST the porting. It would be interesting to see what the muffler gives and would suspect at least 15% so am pretty happy with that and it is nice to get some quantifiable figures on the table for reference.

 

We think that there may be a little more to be had from upping the max revs from 13500 to 14000rpm as it was loading up a little in the bottom of the cut but am very happy with where this has ended up.

[medroberts]

Steve, My 395xp arrived back on Friday at work, so Friday night I put the 24" bar and chain back on and went to start it as normal:blushing: Bl**dy hell there is some compression in it now:thumbup1:I can only start it with the decompressor in:thumbup: I have tried it this afternoon in 2ft piece of oak and cannot slow her down in the cut:lol: What rpm did the saw tach to ? Sounds nice ticking over with M/mod. Many thanks , I will let you know how she gets on , when this weather improves:001_rolleyes:

Med Roberts.

[spudulike]

Steve, My 395xp arrived back on Friday at work, so Friday night I put the 24" bar and chain back on and went to start it as normal:blushing: Bl**dy hell there is some compression in it now:thumbup1:I can only start it with the decompressor in:thumbup: I have tried it this afternoon in 2ft piece of oak and cannot slow her down in the cut:lol: What rpm did the saw tach to ? Sounds nice ticking over with M/mod. Many thanks , I will let you know how she gets on , when this weather improves:001_rolleyes:

Med Roberts.

 

About 12500rpm which is the maximum on a standard machine but on a ported one, is fine and will run easily at 13000 with no ill effects.

 

Glad you like it:thumbup:

[NFG]

Steve, My 395xp arrived back on Friday at work, so Friday night I put the 24" bar and chain back on and went to start it as normal:blushing: Bl**dy hell there is some compression in it now:thumbup1:I can only start it with the decompressor in:thumbup: I have tried it this afternoon in 2ft piece of oak and cannot slow her down in the cut:lol: What rpm did the saw tach to ? Sounds nice ticking over with M/mod. Many thanks , I will let you know how she gets on , when this weather improves:001_rolleyes:

Med Roberts.

 

Hi - sounds like you have a cracking saw there, nice one Spud.

 

 

N

[spudulike]

Hi - sounds like you have a cracking saw there, nice one Spud.

 

 

N

 

Yup, you should read the post Med put up a while ago saying the saw was a bit underpowered , thought I should address this:thumbup:

[SteveA]

Have you pimped a Husky 550 or 560 yet?... or is autotune bit of a mare?

Not that I'm looking to get my 550 ported but who knows, maybe one day!

cheers, steve

[spudulike]

Have you pimped a Husky 550 or 560 yet?... or is autotune bit of a mare?

Not that I'm looking to get my 550 ported but who knows, maybe one day!

cheers, steve

 

I have done the full monty on the 560xp including pop up piston and it is still running around 18 months later!

[MattyF]

It just has a habit of eating starter paws more than 560's usually do as there's to much compression!! , lucky to get 30 hours out of one.

Auto tune is a bit lumpy on this saw but its been rebuilt a few times and its a very early saw so I don't think it's the port work, in all it's an animal and pretty frightening freshly sharpened with an edge off the rakers

[Rich Rule]

Here we go, all fully ported saws that go out of my workshop will now bear a super duper ported label:thumbup:

 

It allegedly gives you 15% extra performance:001_rolleyes:

 

Can I have a few mate for my 200t's, 150t and the 660 you did? Which might I add is blinding!

[Mark Bolam]

I had a play with Rich's 150 a couple of weeks back and can confirm it is a little animal.