Piston Mod

[Codeone]

ok i thought i would start this
as i heard a couple of people talking about at my site
as they was sort of saying you put some sort of packer
in the middle of the piston & piston head
so the gears connector how they should so you dont
get any wear on the piston


anyone tryed this
also whats the best thing to use

thanks codeone

[Caveira]

Re: Piston Mod

Were they using L85's by any chance?

[Codeone]

Re: Piston Mod

nope all m4's im getting some wear on my G&P only a little bit its about a year old

[johnnyj]

Re: Piston Mod

i think your talking about getting the angle of the piston and gear correct ? this type of mod i would only do on a high speed type set up , where is the wear ? and has the piston had the second tooth took down ?

[HuntR]

Re: Piston Mod

That's called correcting the angle of engagement mate. Basicly you want the pickup tooth of the sector gear to have a flat surface on the piston. With stock setups this generally doesn't happen. A flatter interaction will spread the load and generally make the piston last longer. It's not usually needed in stock setup, but many people correct it anyway. The first thing you should do, is shave 1-2 teeth off the back side of the piston, where the sector gear engages. The 2nd and 3rd tooth. This stops premature engagement. Then you'll want to get some washers to put between the piston and piston head.

http://www.zeroin.co.uk/showthread.php?p=184679

If you look at the thread above, it's very detailed on showing you what AOE is and should look like

[magic_golem]

Re: Piston Mod

bang on the money i think hunter :p

[North West Outpost]

Re: Piston Mod

Very good guide, only thing I would add is that you may need to buy some longer bolts that hold the piston head on. Counter sunk machine screws, M3 the length depends on how many packers you have to place. I would also add an ally bearing guide to the piston at this point. This will allow you to tighten the screw nice and tight.

If the AOE is quite a way out, as the sector gear rotates it is basicly playing tennis with the pick up tooth on the piston. With out OAE correction the sector gear is trying to hit the back of the piston in an upwards direction rather than backwards as it will be in the corrected position. It also reduces the piston travel a fraction, only a bonus in high speed set ups, as it gives everything a tiny extra ammount of time to come to rest befor shooting off backwards again.

If there is only a tiny bit of wear and the only mod you are doing is AOE, it probably isn't required. If however you want the experiance or are modifying further, it is worth carrying out.