my 2153

[tree monkey]

oops, need to fix that. I don't have a pic but I epoxied the hole

 

[tree monkey]

ports are ruffed in

 

[riverrat2]

Nice Stuff!!! Thanks for sharing Scott

 

[tree monkey]

the transfers take more time then the rest of the saw. it's the most important part of it too. I widen most 4 port engines, but rarely widen a 2 port.
the main port is towards the exhaust, secondary towards the intake.
I widened the mains towards the exhaust port. I do this so I can keep the angle of the port angled towards the intake. I do my best to keep the tunnel the same width and height. a small taper is ok(wider at the base). on the secondary's, the port match didn't allow much room to widen the port. so I cut the port on an angle from the base to the window, and cut the web on an angle to match.

 

[tree monkey]

the secondary look like it has a dip in it, i'll have to look at it again, but I think it's a shadow.
I like to have the last, about, 1/4 " of the port to be flat. parallel to the piston crown. the secondary's are angled upward stock, and I usually cut through then to get the shape I want. the roof of this port has to be very thin. I want a nice even radius up the back.

 

[Adirondackstihl]

 

[tree monkey]

I mark the top of the intake on the piston at bdc. and the intake shape on the bottom.


I raised the intake port .100.



marked the flour of the exhaust port at bdc, and the port shape at tdc.

 

[tree monkey]

I put the ring on the piston to hold it in place. I line up the bdc marks in the ports. I then mark the piston to the cylinder. this mark might over lap the port shape mark. you need to leave .050 over lap. in other words, DON'T FREE PORT IT.

 

[TJ the Chainsaw Mechanic]

 

[tree monkey]

I raised the flour of the intake.

 

[tree monkey]

as long as I don't need the clearance anymore, and I removed a lot of metal, and it should improve flow, then why not.

 

[tree monkey]

need to match the muffler to the heat shield



had to kill the cat

 

[tree monkey]

added a port to the clutch side



original port was enlarged as much as possible. all saws that I port will have forestry approved screens in them when they leave my shop

 

[tree monkey]

when using a 359 intake system, and hda 199 carb, things become a little tight. trimming this helps a lot.

 

[tree monkey]

sense i'm not using the zama, I won't be needing that little manual fuel pump anymore. I think it's a 4 penny nail. fits tight. a dab of durco in the hole, tap the cut off nail in, and a piece of shrink tube. works for me

 

[tree monkey]

numbers. I almost forgot the numbers
intake 144
exhaust 152
transfer 110
blow down 21
squish 17
base gasket na

now all I need to do is go put it together

 

[tree monkey]

 

[tree monkey]

 

[tree monkey]

i'll update this in the next few days. i'm using a 20" 3/8 bar with 72 jp chain

 

[bryanr2]

wow 250psi. video?