What do this thing bore-up, what are a non ported cylinder

[sebdark]

Hi!

The reference thread all is about http://www.airsoftcanada.com/showthr...69#post1136069

Resume:
I want to replace my 360mm inner barrel (G&G gr16 m4 Carbine CAS version) for a 650mm. I buyed a 290mm silencer and it should be enought to hide the inner barrel.

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Someone recommende me to "You'll also need to switch out your cylinder for a non-ported one, and in the case of the 650mm barrel you may need a bore-up kit."

But I really don't know what a bore-up kit do. (pm me a model compatible please) And what the kit should contain? That why I hope someone will link one

Finnally what is a non ported cylinder?

Thank

[L473ncy]

Bore up means larger bore on the cylinder.

Essentially what you are doing is increasing the bore (cylinder volume is (pi*r^2)*h). By increasing "r" (radius) you effectively square volume.

As for the ported or non ported, it's like ported pistols. Not really a good explanation but I'll try to go further.

With a ported cylinder you have "ports" for air to escape, this from what others say allows your pistons stroke to go all the way forward so your BB gets the most amount of "push" that it can.

With a non ported cylinder the theory is that, because you have such a long barrel the piston should complete the stroke before the BB exits the barrel therefore giving the maximum push to the BB.

There are different ported cylinders for different lengths of barrels so keep that in mind. From my research Prometheus offers a variety of ported cylinders to match specific barrel lengths.

[SHÖCK]

In simpler terms, inside your mechbox there is a cylinder and a piston. The piston gets pushed into the cylinder and compresses the air which comes out of the nozzle to propel the BB. Think of a syringe.

A bore up cylinder is one with thinner walls but more interior area so there is more air inside. Matched with a bore up piston head, the air volume compressed is greater.

Cylinder ports are holes in the side of the cylinder that allow air to escape for correct cycling with shorter barrels. If you have a really long barrel, an unported cylinder doesn't allow the air to escape during a stroke and gives the bb more pressure to properly make it's way down the longer barrel.

Kit for M16:
http://www.airsoftparts.ca/store2/in...roducts_id=682

[sebdark]

Thank for the awesome answer!

[CDN_Stalker]

Actually, ported if for shorter barrels, and the reasoning behind it is this: The piston will be at it's full speed by the time the head passes the port, causing the sudden and sharp air pressure forming behind the BB and propelling it. Non-ported, or full cylinders, are as stated above.