Spuds Porting and Tuning Thread

[spudulike]

ok that sounds good i was just a bit worried about the scoring :thumbup:

 

Get a picture up and lets have a look at it!

[shavey]

ok i will do that on wedneday thanks

[sloth]

 

Fair enough, I guess I asked for that! so how does it work? Does it actually 'pop up' or is the lump on its top rather than having a flat surface the clever bit?

[Gary Prentice]

I have just spent two hours reading about porting chainsaws.

I feel mischievously excited and am planning on buying a range of files, a dremmel and some new drill bits tomorrow.

 

I will possibly have a range of Stihl chainsaws for sale next week

 

 

(that do not run for some reason )

 

I think im going to practice first on some scored cylinders first

 

I knew you were OCD:lol:

[wyk]

Fair enough, I guess I asked for that! so how does it work? Does it actually 'pop up' or is the lump on its top rather than having a flat surface the clever bit?

 

It helps to increase the compression ratio of the engine. The more compression you have, the more torque your saw can produce after a fashion. It can also allow for more aggressive port timing and tailoring the saw to run a certain way as well. That piston I showed, with some modifications, is running in this saw here:

 

[ame=http://www.youtube.com/watch?v=OptyXKhsPbo]2165 BB ported with increased compression - YouTube[/ame]

[sloth]

Thank you

[Goaty]

Had a little play on my recently spuderized 346xp today, albeit with a brand new 13inch bar and chain with 8 pin sprocket rim. It now runs with ease and speed beyond its previous performance. I have to agree on the reduced fatigue factor with porting. The only question in my mind whilst using it was, it would cost virtually nothing for the manufacturers to incoperate porting so why don't they?

 

Emissions and sound levels?? Is all I could come up with.

[wyk]

Had a little play on my recently spuderized 346xp today, albeit with a brand new 13inch bar and chain with 8 pin sprocket rim. It now runs with ease and speed beyond its previous performance. I have to agree on the reduced fatigue factor with porting. The only question in my mind whilst using it was, it would cost virtually nothing for the manufacturers to incoperate porting so why don't they?

 

Emissions and sound levels?? Is all I could come up with.

 

EPA - which is also why they are lean with tiny outlets from the factory. Same reason for lower compression.

[Goaty]

Environmental protection agency? The instigator of those non tamper carb screw caps.

 

PAH! PARTY POOPERS.

[wyk]

The US EPA cracked down pretty hard on 2T motors and producers back in the 80's and 90's. It is one of the reasons you see so many US manufacturers die back then, only to be reborn as Chinese or otherwise foreign to the US companies in the form of cheap plastic junk after selling off their names.

 

It is also one of the reasons we have autotune, MTronic and strato saws.