What piston for my mosfet

[deakenj]

I am in need of some serious help.
I installed a mosfet in my ics m4 about 6 months ago, in that time i have just today shattered my 3rd piston head.

Can anyone give me a reason why this is happening?
I do alot of single firing so i want something really strong and was thinking aluminium piston and piston head?

Any and all help would be great.

[jagillham]

Re: What piston for my mosfet

Where exactly is the damage? What pistons you been using? What spring you got in there?

[deakenj]

Re: What piston for my mosfet

All 3 piston heads have shattered and broken off the piston, There is an m100 spring in there which has been cut down so the fps is around 335. The first piston head was standard, the second an ics standard head and the third was a guarder piston head.
The piston itself is a standard ics one and never had any damage.
It just seems to be going through heads.

[richardy]

Re: What piston for my mosfet

if your shattering piston heads you need to install a different cylinder head / piston head combo, changing the piston wont make a difference.

another thing that could be happening is the piston head comes loose through vibrations and when its loose it shatters

[deakenj]

Re: What piston for my mosfet

That was going to be my next question, the cylinder head was non standard which i had lying about.
Is there any specific combo that i should be looking for to suit my high speed and rapid firing?

[richardy]

Re: What piston for my mosfet

thats why then its probably old and the paddings not softening the impact anymore or the shapes arnt a good fit.

the easiest way with out going into the different shapes is to simply match brands...

guarder piston head with the guarder cylinder head...

Prometheus cylinder head with the prometheus piston head.

etc etc

you dont want uneven shapes impacting, you have to make sure its flat on flat.. maximum surface area.

for instance the silent piston head which is shaped to fit the matching cylinder head would break real quick on a standard cylinder head.

[deakenj]

Re: What piston for my mosfet

Excellent, thanks for the help Richardy, this is where i have been going wrong.

[sj_asc]

Re: What piston for my mosfet

Check the padding on the cylinder head.
What Cylinder head do you currently have?
The majority of "reinforced" cylinder heads have an inner taper (V1/2/3/4 etc...), Prometheus, Systema, Deepfire etc.. all follow those designs, the reduced surface area means smaller more direct areas of the piston head will endure more stress.

Other manufacturers like Guarder/Modify use non inner tapered cylinder heads (except bore up sets) just like TM's stock heads.

Whilst the tapered cylinder heads offer minor advantages in some areas they offer problems in others, many polycarb piston heads will fail sooner than they should to as a result of the cylinder heads design.

Under any high spring load or high cycle rate i would strongly suggest using a standard non tapered cylinder head. Against the tapered cylinder heads unless you have the corresponding tapered piston head (like the silent or bore up sets).