Porting a 2139t or 338xpt

[davidwyby]

Some video would be cool!

@huskihl you scene dis?

 

[AKJonsereds]

Sorry, haven’t done a video of its current state in wood and won’t be able to until we go to the cabin at the end of the year.

But here is a little piss rev…. If I figured out the video thing properly.

 

[davidwyby]

@AKJonsereds that is snappy for sure! Lot peppier than mine.

 

[AKJonsereds]

The big thing I have to say about ported saws, it is hard to get a reading on performance gain. I bought a stock 2139t, 200t, and T540xp to compare it with. After warming up all four saws for testing, I find all my cutting done and the stock saws never got a turn. If they do get a chance, I push too hard once and move back to my ported saw.

Gave the second 2139t to my best friend, sent the 200t to my uncle, and left the 540 at fish camp. My only stock saw available for comparison now is a 2095…

Will try to do a cutting movie in the future anyways….


Sent from my igloo

 

[NPKenny]

You said you set your squish…. Do you mind clarifying? It looks like a clamshell cylinder.

Are you referencing turning your pop-up on the lathe?

Thank you! I have an orange one in line for a build.

 

[AKJonsereds]

I had the popup made and turned it to make it pretty. Put it all together and had 170psi compression which I believe is similar to a stock 200t? Checked the squish and it was large (memory fails me here but I think over .040) so I took it apart and cut the clamshell until I got my squish. It involved a flat sanding block/table and a sanding mandrel drum. Lots of trail and error—-i took too much off of a corner of where it contacts the bearing and needed a jb weld save. Also used a fresh gasket for assembly.

I probably wouldn’t do this for a friend, but it is my saw and I wanted it done. Few things are impossible if you set your mind to it.

All that said, squish set proper, it was about 210psi. After running it hard it is up to 230psi but I am guessing it is actually somewhere between. Maybe a little residue oil or carbon in there…. If it stays I may raise the exhaust a tiny bit….

 

[AKJonsereds]

Another bit of advice, the 45cc top end has good torque for its size, but I spent a long time on transfers. The 38cc top end has far better transfers for just about everything.