2.5 pistons

[dean jones]

how can you tell the differance in cast or forged pistons? can you look at them and tell or do they have a certain parts# ? thanks for the help.:confused: :confused:

[O/B Dude]

Easiest way to tell is look at the back side of the piston. Is there a casting line with "flash"?

[Jay Smith]

Most all cast pistons have a very beefy build up of material around the ports on the inside of the skirt to build strength. Also if you have machined many pistons it is very noticeable when finished the spoil from the cast piston will look like dirt , will machine very easy and will not gum up on tooling as the forged spoil is very destint and will gum up on tools if not ran at the proper RPM and coolant/lubricant used with high helical angled end mills made for alum.

Cast is VERY brittle and will simple shatter when dropped or abused , the forged being alot tougher will wad up and bend without breaking. We have found that cryoing makes the forged pistons more mill friendly to cut and not so prone to mishape in the bores with abuse of high rpm and big compression, they will also seem to maintain thier "round shape" a bit better when treated also..........

[dean jones]

THANKS FOR THE HELP GUYS?