saw porting

[mixedangased]

anyone recomend any good books on 2 stroke porting ?

fancy having a play an a 254xp

[D A Tree Surgeons]

anyone recomend any good books on 2 stroke porting ?

fancy having a play an a 254xp

 

Not sure of any books

id get in touch with spud on the (whats on your bench today )thread

he has ported two of my huskys and they are animals :thumbup1:

[spudulike]

There is much that can be done on a 254XP, the design leaves much on the table.

 

I have read one book that does clarify a few facts that I had already heard from others and does give an interesting insight to two stroke tuning in a very indirect way but if you want to do it, learn what the constriants are and work within them.

 

The 254XP I did was scarily quick and was one of the few saws that took me by surprise when I fired it up after porting:thumbup:

[wyk]

I would suggest doing a google search for:

 

"mastermind meets the" and "porting 101" and use the quotes in the search.

[mixedangased]

thanks for the reply guys,

have been watching a few vids on utube and im not unacustomed to porting as used to do a lot with mini engines 35 yrs ago,but never done a 2 stroke,

will see what i can find and probally just clean out a feather/polish the ports to start with and mod the exhaust and see how that works.

[wyk]

I'd go to the AS site and look up masterminds threads and the porting 101 threads before you tear in to a jug like a 254xp. He does start to finish porting walk-throughs.

[wrsni]

feather/polish the ports to start with

 

Don't waste your time polishing inlets and transfers, they're better a bit rough. By all means remove any lips and obstructions but the actual surface of them benefits from a bit of texture to create turbulence.

 

Exhaust can be polished to mirror if you feel inclined.

[wrsni]

anyone recomend any good books on 2 stroke porting ?

 

There's a pile of stuff about and in one respect they're a good read but in another respect they do little to actually prepare you for doing any practical work.

 

Anything by Kevin Cameron is pretty good as he's both a good engine man and a very good writer. You'll also find quite a lot of papers on the internet now from Professor Blair but bear in mind these will be presented from a scientific point of view rather than for public consumption and will have been written accordingly. Also bear in mind there's a big difference between tuning and porting so don't think info on one will automatically relate to the other. It's entirely possible and in many cases preferable to tune an engine with no porting work whatsoever.

 

If you want a quick fix you'll not do much better than the Macdizzy site. Plenty of stuff there to keep you going for a long time!

[H-A]

quite a lot of papers on the internet now from Professor Blair but bear in mind these will be presented from a scientific point of view rather than for public consumption

 

Blair did a lot with British Seagull, developing the QB range (Queens Belfast).

 

There are a few 2 stroke tuning books to down load on the net.

 

I have 3 in PDF form, not chainsaw specific but same principles apply, pm me if you want me to email them to you.

 

H-A

[spudulike]

Don't waste your time polishing inlets and transfers, they're better a bit rough. By all means remove any lips and obstructions but the actual surface of them benefits from a bit of texture to create turbulence.

 

Exhaust can be polished to mirror if you feel inclined.

 

If you look at many inlet manifolds, they are dimpled to cause a good mix of fuel and air through turbulence.

 

I don't personally piss around with polishing, there is a limit to how much you can do without getting fanatical and obsessive about it shaving a tenth of a second off a cut - I have ben there:001_rolleyes:

 

Obtaining more revs and torque and getting 80% of the 100% that is ever available is what it is about - leave the racers to chase the last 20%.

 

Saying that, I am starting to think about an old 066 I have and want to make a heavyweight racer:blushing: