Porting

[Deleted member 117362]

All this porting stuff is stupid! Your just cutting firewood! Recipes, are you baking a cake? Ported saws are fun though.! If you continue, these chainsaw porters will toast you. I'll deflect some of the negativity away from you Bill. Stepfather built high performance motors as a hobby, always hated seeing him start a new one, unless it was for me or my brother, lapping valves and polishing intakes to a mirror finish was a pain. He had OCD when it came to decking, shaving heads, valve sizes, trimming piston skirts, filling block voids to stiffen them, on and on! He was old school, how did you time cars, trucks of motorcycles? I want you to say with a timing light, so I can tell you he thought that a light was the worst way.

 

[CR888]

Here’s a partner take on there T exhaust port, interesting? What if we added three early exhaust grooves? Or camel humped the top of the exhaust port? The piston is driven by the exhaust gases there useless as piston gets near the exhaust port the most pressure and downward force is done in the chamber. There is a ball cutter in the carbide bits to chamfer the humps or cutouts. The blow down could be increased to the point the crankcase pressure could be actually sucked up by the leaving gasses? Not only forced up by the crankcase pressure. Just thinking out loud.

https://www.arboristsite.com/community/attachments/img_20190801_200928-jpg.750677/

This was done years ago I think MAC did it too on larger bores to make starting easier as it allows compression to bleed off slowly. It also makes the saw less noisy. At high rpm it should'nt have too much effect at all. I don't thing it will increase charge in your transfers HB.

 

[Chainsaw Jim]

Not using a degree wheel is like letting a blind monkey wipe your ass.

 

[CausticUC]

Not using a degree wheel is like letting a blind monkey wipe your ass.

It's a good option if you cant afford a high resolution pulse meter or frequency counter.

 

[rupedoggy]

Not using a degree wheel is like letting a blind monkey wipe your ass.

How do you train him to do that?

 

[cuinrearview]

Or we could have just used the search function...

https://www.arboristsite.com/community/threads/porting-101.108900/page-5

 

[Huskybill]

Should do a sticky post and make a nice presitation. With pics everyone can open.

 

[cuinrearview]

Not everyone needs the info spoon fed to them.

 

[Huskybill]

Not everyone needs the info spoon fed to them.

let's see some pics of your porting?

 

[cuinrearview]

let's see some pics of your porting?

There are pics on this site. In fact, I'm pretty sure you commented on how I needed to knife edge this or camel back that. I just started and I'm a hack. I'm very careful with what I post because I don't want anyone to think the junk I build is "the way". BUT. I've read enough to know helpful info when I see it.

 

[Huskybill]

Let's see your porting pics? Hack or meat cutter 101?

 

[cuinrearview]

PM'd

 

[Huskybill]

Post them here

 

[cuinrearview]

Anyone that wants to see the 350 and 2147 can. They're right on this site. A little more searching would find a 346 with crank stuffers.

 

[olyman]

When porting we open up the ports and raise or lower them don’t forget to chamfer the sharp edge created when we go from the port into the cylinder. I wrap a piece of fine grit paper on my finger tip and sand the edge of the port to the cylinder bore chamfer it. Remove all sharp edges and corners so the piston ring will pass over them and not break the piston ring. The action is a must do when porting.

New to porting or want to port take note.

………………………………...

 

[Huskybill]

………………………………...

What’s the point?

 

[Chainsaw Jim]

Ok I'll go first.
I call this one "Fu Manchu"

 

[Huskybill]

Nice work Jim. That’s on the intake side. Husqvarna in 84/250 had a similar setup added two more transfer ports besides the four. Funny a lot of riders couldn’t figure why the laid back bike had so much pep. They also put two windows along side the exhaust port taping into the exhaust port from the cylinder. I guess great minds think alike. I wonder if the two windows on both sides of the exhaust port can be added. They were slots the same height as the exhaust port.

 

[Wood Doctor]

Stihl does a "good" job porting their blower mufflers. The exhaust all has to go through a wire mesh container, smaller than the size of your little finger. That cakes up with deposits in a couple of years or less and chokes the engine so bad that it won't run above idle. Eventually it won't even start.

 

[Huskybill]

I was running 38:1 ratio in my saws at first my little 240sg clogged up the spark arrestor. Using the husky 2t oil. Once I learned how to fine tune the carb adjustment it never fouled the spark arrestor again. I took a large sewing needle and cleaned the screen hole by hole. The 2100/266 had no problem with the 38:1 mix.