Echo CS-310 build

[Red97]

I'd like to know that myself. I don't think it's a clone but I believe they use the same piston. I'd like to do any upgrades if any exist between these two models.
I hope someone comes along to have an answer for that. @SawTroll...I'm wondering if there are any Husqvarna pistons 38mm with 8mm pin holes. It's 13.15mm from to edge of pin hole to crown edge which would be 17.15 center hole to crown. I'm after a piston that's single ring with about one to two millimetres taller head so I can tighten the squish and flatten the band a bit for higher compression. My ideal plan is to find a windowed piston to do a major overhaul on those pinched off turd shaped transfers tunnels. They're larger diameter through the centre than at each opening. That cannot maintain or increase velocity in my opinion. To me it's like airing your house out by opening a small windows instead of two doors at each end.

Think the echo 3600 may be 38mm?

Large brush cutter??

 

[Chainsaw Jim]

I don't like much about this cylinder as far as thickness. Yeah it'll cool better but I'd prefer a little more meat on the bone to grind. The shape of the exhaust would make it insane for modding if the walls weren't so thin, but it'll still work. The transfers are very closed off at the entry point.

I opened those up a tad bit.

 

[Chainsaw Jim]

Here's the intake and exhaust.

 

[Chainsaw Jim]

One more pic of the finished transfers.


I also swapped out the plastic boot clamp for a metal one from 044/046.

 

[Chainsaw Jim]

A had a chance to fire this thing up and I'm very happy with the way it sounds even with the stock muffler, but that muffler is still holding it back. I'll have that thing done here in a bit..I hope.

 

[Red97]

Did you degree it? Curious what it was stock?

 

[Chainsaw Jim]

I didn't degree it. I have another one to use for stock numbers when I dig the degree wheel out. Just looking at the cylinder you can see the transfers are very close to the exhaust. I measured them and it was somewhere around a 10-15 degree difference.

 

[Dub11]

Nice and so closed ports and solid piston?

 

[bikemike]

The intake is nice.View attachment 43420
But the exhaust is strange. It seems like they're going for a cyclone like twisting effect.View attachment 43421

The tiny carb is for the tiNY exhaust port. that port is saying to me you need to widen it up ALOT.

 

[bikemike]

Did you cut any of the skirt off the piston for transfer ports? and that carb. Yes the carb how more did you open up the venturi ?

 

[Dub11]

scouting out the hl and the husky 335 is a 38 mm windowed piston not much else on the info

 

[Chainsaw Jim]

Did you cut any of the skirt off the piston for transfer ports? and that carb. Yes the carb how more did you open up the venturi ?

I didn't do anything to the piston yet. I've also left the carb stock until after testing it out in wood.

Nice and so closed ports and solid piston?

Solid as they get. The Husqvarna pistons wouldn't work with 10mm pins. I'm going to back burner the piston upgrade idea until I decide to build it into a little racer.

 

[Chainsaw Jim]

This was a bit annoying to deal with. That cat tube steel is very thick. At least I wasn't forced to split the muffler to do it.

 

[Dub11]

This is were I can get stupid but is it possible to use bushings on the 8mm pin in the piston?

 

[drf256]

Jim,

What effect do you think removing all of that material from the lowers will have?

Seems like you may lose transfer pressure and you'd need to raise the uppers a bit.

Odd port geometry for sure. The asymmetry is confusing. Do you think you could induce swirl in that chamber by raising one side of the uppers more than the other?

Looks like the set of transfers furthest from the exhaust port will need more time to fill than the other set.

I like little saws that pack a punch.

 

[bikemike]

Jim,

What effect do you think removing all of that material from the lowers will have?

Seems like you may lose transfer pressure and you'd need to raise the uppers a bit.

Odd port geometry for sure. The asymmetry is confusing. Do you think you could induce swirl in that chamber by raising one side of the uppers more than the other?

Looks like the set of transfers furthest from the exhaust port will need more time to fill than the other set.

I like little saws that pack a punch.

It will help it breath better and be less turbulent through the lower passage. That is a clam she'll and not much for the gasses to flow through once the bearings and seals are in place

 

[jake wells]

This was a bit annoying to deal with. That cat tube steel is very thick. At least I wasn't forced to split the muffler to do it. View attachment 43646

i told ya and they use good steel in those mufflers so modding them can test your patience.

 

[bikemike]

i told ya and they use good steel in those mufflers so modding them can test your patience.

Very true. Also why oem muffler cost so dang much

 

[Chainsaw Jim]

Jim,

What effect do you think removing all of that material from the lowers will have?

Seems like you may lose transfer pressure and you'd need to raise the uppers a bit.

Odd port geometry for sure. The asymmetry is confusing. Do you think you could induce swirl in that chamber by raising one side of the uppers more than the other?

Looks like the set of transfers furthest from the exhaust port will need more time to fill than the other set.

I like little saws that pack a punch.

Basically what bikemike said. It will improve throttle response along with better flow.

 

[Chainsaw Jim]

i told ya and they use good steel in those mufflers so modding them can test your patience.

The hardest part was coming up with a procedure to do it while having no idea what the cat looks like. I actually ended up doing it the hardest way possible.