can we have basic porting term thread?

[ft. churchill]

Oh yeah the ports have started being ground on so they are rough yet, I'll see if I can find a port chamfer for you.

 

[jmssaws]

Can we ban the term newb or newbie?
I don't care if you never ran a saw or if it's all you have ever done and I don't think anybody else cares either.

 

[ft. churchill]

This is what we call a open port design. It came before the closed port design. Saws from the 50's 60's and 70's and some even into the 80's had the open port design. the piston has a full skirt and it forms one wall of the port. This is a new old stock homelite super 925 xl. There is no intake port as this saw uses reed valve induction. The carb feeds into the crankcase through the reed block. Some folks refer to the angled third port on the right hand side of the cylinder a "boost port" , although it is not a true boost port like the big McCullochs or motorcycle engines have.

 

[ft. churchill]

Here's a Husqvarna 385 xp cylinder. It's in the closed port family of saws, but we just call it a quad port cylinder. It has two separate tunnels to each of the port on each side of the cylinder. Hence a quad port. There are some intermediate designs, Echo cs 8000 comes to mind, with one large lower that splits into two port per side. The newest, stronger running designs seem to have the lower transfers feeding from the case and not the cylinder wall.

 

[ft. churchill]

Top one is a D shaped offset combustion chamber on a Stihl 090, has dual closed port transfers, lower pic is a 385 hoosky with a central combustion chamber.

 

[awol]

Bottom feeders we call 'em.

 

[ft. churchill]

Here's the money shots. A degree wheel, you'll need to make one using a drill chuck to get the blow down numbers. Many builders here will share with you on how to use one. It's how I learned.

 

[cobey]

You can send me those "junky 024's"

024's are ok these were beat up
Saws..... very worn, bad plastic
Runable but poor condition

 

[Adirondackstihl]

 

[Adirondackstihl]

 

[czar800]

View attachment 9819 View attachment 9820

Here's the money shots. A degree wheel, you'll need to make one using a drill chuck to get the blow down numbers. Many builders here will share with you on how to use one. It's how I learned.

When I finally put a wheel on a saw and played around with it is when it really started clicking. Funny thing is once I got the wheel it makes you start thinking of a hole other ball of wax!!!

 

[jmssaws]

When I finally put a wheel on a saw and played around with it is when it really started clicking. Funny thing is once I got the wheel it makes you start thinking of a hole other ball of wax!!!

You have tumbled down the rabbit hole.

 

[dall]

i have a degree wheel i bought when i was building my old truck motor comp cams degree wheel with dial indicator but you guys are speaking a whole nother language on this to me

 

[ft. churchill]

Maybe we can get cobey infected with our sickness.

 

[ft. churchill]

i have a degree wheel i bought when i was building my old truck motor comp cams degree wheel with dial indicator but you guys are speaking a whole nother language on this to me

That is where mine came from, rescued from a life of dialing in big chevy cams. It now lives in a world of much higher gains of performance and vastly higher RPM's.

 

[jmssaws]

i have a degree wheel i bought when i was building my old truck motor comp cams degree wheel with dial indicator but you guys are speaking a whole nother language on this to me

Study and read everything, get that wheel on a saw and it will start to make sense.

 

[czar800]

You have tumbled down the rabbit hole.

It's so addicting!

 

[dall]

lol i bought it and used it once used the cam bearing tool twice lol

 

[jmssaws]

lol i bought it and used it once used the cam bearing tool twice lol

I've got a cam bearing tool I've never used. Lol

 

[jmssaws]

I've started trying to get everything I can out of a saw and it has become a obsession, once you port one and see how it runs then you think,I believe I can get more! But it never ends.