Just Another 395xp Build Thread

[spencerpaving]

where abouts are you again

Southern hemisphere

 

[Postrip]

Ok... A little work on the piston.
Keep in mind this is a basic worksaw build for an older guy.
He's wanting more power,smoother running,but not hard starting,and certainly wants reliability.
My own personal race saws are taken much further in all aspects of the build process
Standard piston..

Modded piston..

No need to go ballistic here, just cleaning out the casting marks from the transfer windows.
This will lighten the piston a little,but more importantly "aids flow"
Note: I always leave both gudgeon pin clips with the tang at the top.
It may never make a difference, but at 13,000+ rpm's I like to have things symmetrical

 

[Postrip]

As the owner wants to keep it simple & low key, we are only doing a gasket delete.
After measuring squish it'll have .70mm squish clearance, that's a little excessive 4 my liking but...... on with the show.

Setting up degree wheel 2 measure some ports

And roughing in the transfers...

 

[peter92]

As the owner wants to keep it simple & low key, we are only doing a gasket delete.
After measuring squish it'll have .70mm squish clearance, that's a little excessive 4 my liking but...... on with the show.

Setting up degree wheel 2 measure some ports
View attachment 57704
And roughing in the transfers...
View attachment 57705[/QUOTE
looking forwards to see what the port timing is

 

[peter92]

looking forwards to see what the port timing is

 

[Postrip]

Port timing will be...
Transfers 118
Exhaust 98
Intake 80

 

[peter92]

Port timing will be...
Transfers 118
Exhaust 98
Intake 80

if you take too much out of the ports , will it make the saw run hot , so what would be too much on those numbers to throw the cylinder away , im just trying to understand and learn about this

 

[Postrip]

if you take too much out of the ports , will it make the saw run hot , so what would be too much on those numbers to throw the cylinder away , im just trying to understand and learn about this

It really depends on what you need to achieve!
Numbers 4 my hotsaws are way different to these numbers,as is the porting.
Most important thing 4 a beginner is to not widen ports 2 far.... it will "free port" if you do.
A general rule of thumb is 1 up/1 down
1mm up for exhaust,1mm down for intake.
I've done quite a few different models now, changed things around a little,and gained some great results

 

[peter92]

It really depends on what you need to achieve!
Numbers 4 my hotsaws are way different to these numbers,as is the porting.
Most important thing 4 a beginner is to not widen ports 2 far.... it will "free port" if you do.
A general rule of thumb is 1 up/1 down
1mm up for exhaust,1mm down for intake.
I've done quite a few different models now, changed things around a little,and gained some great results

thanks for that info , it is just what i was after, whats "free port"

 

[Postrip]

thanks for that info , it is just what i was after, whats "free port"

Lol....it's when the port is wider than , or below the edges of the piston skirt.
I've seen a few cases of both

 

[peter92]

Lol....it's when the port is wider than , or below the edges of the piston skirt.
I've seen a few cases of both

thank you , i thought it may have beensome thing like that , but just wanted to be sure

 

[Postrip]

A spare half n hour this arvo,seen some roughing in on the intake port

 

[danimal]

Lacks character. There's no holes in the front of the cases or recoil. No cracked clutch cover or dented muffler. Operator presence lever is still operational. Top handle isn't on a funky angle. Still all one color. Sumptin ain't right here

Let me borrow it, i'll let my buddy run it for a day. He will put that 3 yrs of logging look on it..

 

[XP_Slinger]

Great thread! Very generous in sharing details and great pics.

Jacking up the timing so the transfers are opening before the intake is closed is also a version of "free port"...Correct?

Sub Sub Subbed

 

[Postrip]

Just a few pictures of the finished cylinder porting

 

[Postrip]

Great thread! Very generous in sharing details and great pics.

Jacking up the timing so the transfers are opening before the intake is closed is also a version of "free port"...Correct?

Sub Sub Subbed

That would be correct.... however it's nearly impossible to achieve.
Especially on a husky,they have long & wide piston skirts

 

[Postrip]

A little time this arvo seen the muffler de-restriction begin...

 

[Postrip]

Completed muffler from a few weeks back!

 

[Postrip]

A shot of the exhaust port, & the muffler heat shield all port matched with the muffler.

 

[Postrip]

Ignition timing has been left stock standard at this point.
It's running a 20" sugi bar 3/8 .058 LGX chain
Fuel is 98oct unleaded mixed at 40:1 royal purple tcw111 racing synthetic oil.
I test run the saw this morning, will upload a video shortly.