Piston Porting

[joker060]

2 questions on this topic.

1> What does porting the piston acheive?
2> How does one go about porting the piston? (drill bit size, amount of holes, and spacing)

Thanks for any and all help.

[damage]

1> What does porting the piston acheive?
Increase in FPS. 10-15fps

[ILLusion]

Do you mean porting the piston head or the piston?

Regarding the piston head:

1>
- More consistent air seal
- Decreases battery consumption (due to reduced drawback resistance)
- Increases ROF (again, due to reduced drawback resistance)
- *Slightly* improved velocity
- Reduces/negates barrel suckback

Most importantly, it improves shot consistency.

2>


When you remove the piston head, you can seperate the face from the backing. The back should be able to just slide off the screw, if it wasn't moulded too tight to it. You can put 4 to 8 holes, but I don't think you need to go as high as 8. However, going up to 8 holes, I highly recommend you use a smaller drill bit, otherwise there may be too much air moving around for an efficient seal.
There already exists four "flash marks" from the injection moulding, located concentrically around the piston head's face. Use those as markers, as they're evenly spaced out.


Regarding piston porting:
1>
- Reduces load weight for increased ROF (due to the piston being lighter)
- Increases gearbox durability (due to the lighter piston carrying less momentum to slam into it.)

2> Remove any material unrelated to structural integrity.

[joker060]

I meant the piston head but now I am curious. How do you port the piston itself and will a stock piston handle porting??

[ILLusion]

I don't have any pictures of it because I've never done it. I found no need to, it's already light enough as it is. But you're basically just removing excess material. You're turning it in to a skeleton. It reduces structural integrity, but as long as you leave enough material to take a structural load, it can be done. I've seen random pictures here and there on the 'net of pistons that people have done.