Echo 330T chainsaw gift

Kimberly it has to do with some of the steps used in modifying a chainsaw cylinder for increased performance.
Changing port shape is basically just that, the intake and exhaust ports are changed to optimize air flow into the cylinder, and spent exhaust out of the cylinder.
Port timing is basically how long the above mentioned ports are open, or closed as the piston travels up and down.
Cutting squish......@mdavlee can take that one, as I'll probably screw it up, but I know it raises overall cylinder compression.
Modifying the muffler is pretty straight forward. The larger exhaust opening increases the flow rate of spent gasses, and heat. Allowing the engine to have better air flow, and reduced heat build up.

I need a nap.

 

Cutting squish or setting it has to do with decreasing or setting the piston clearance from heat at top of travel to some number that the builder wants to hit. What is it like 2 or 3 thousanths? The can accomplish this by different piston turned down or usually they cut the cylinder base down and remove the base gasket till the desired gap is achieved. Cutting material off the bottom of the cylinder mounting surface makes the cylinder shorter thus making the piston come closer to the top of the head when listen is at up stroke. This thus changes when the ports are open as the piston goes up and down thus requiring port work to bring it back to timing numbers the builder wants.

This might make no sense as I dont explain things the best sometimes.

MDavlee can probably fill in the blanks and do better than I anyway. And randy or Mastermind is a member here as well. The guy were talking about.

 

So this mainly increases the pressure the air-fuel mixture is under before combustion? I would need to read up on 2 cycle engines some; four cycles I understand; intake, compression, combustion, exhaust.

 

Yes but reducing the clearance to the piston. Or decreasing the volume with piston all the way up your "compression " increases.

Two stroke is very similar to 4 in many ways. But different in many as well. Each up stroke on a two cycle is a power or combustion stroke though. Each time the cylinder fires and piston lowers and exposes the exhaust part first w spelling the gasses from combustion. Then as it goes Carter down still the intake port is exposed sucking in fuel and air. Back up and all ports close off and fire again.

Thats very simplified. There is transfer ports and all kinds of stuff I barely understand so this is where somebody like mastermec, mastermind, Dex, mdavlee or someone else much more verses in this than me can get much more detailed if you like. I guess I could of paged them and not just wrote their names?

 

They are talking about ways to modify the cut outs in a cylinder. Since our 2 strokes move fuel through the crankcase before bringing it to the top to be burned, you can affect how big the passage is for that transfer but by cutting down further into a cylinder you can also get the fuel delivered earlier in the cycle to that combustion chamber. Even the piston skirt that covers the ports can affect how freely fuel flows in that flow path. The obscure language is talking about different ways to do that reshaping.

 

I want that saw!!!! I wish we could work out a trade!!! Need a well used I mean never abused ford ranger? I'm thinking the 290 and 460 would be an even swap.