Darren@JDM

iTrader: (53)

Set of standard forged spec c pistons.Removed from 10k car due to big power rebuild.They fit standard 92mm bore and come with pins.Open to offers

TonyBurns

iTrader: (3)

What year car are they from Darren as anything from an 03 onwards are not forged.

Tony

fpan

iTrader: (11)

Don't all JDM Imprezas come with forged pistons?

Midlife......

iTrader: (2)

I thought they stopped them at the end of 2002 and went over to a word I can't spell LOL

Shaun

Darren@JDM

iTrader: (53)

As far as i was aware they were forged as standar on the spec c.The car reg for 2011 buts its on a 53 plate.Thanks

Maz

iTrader: (34)

Hypereutectic.
You are right as is Tony. Post 2002 the pistons were not forged but hypereutectic cast alloy. The reason for this is A, cost; forged pistons are much more costly to produce and B; due to emission controls. Forged pistons when cold are a slightly 'loose' fit in the cylinder, allowing small amounts of fuel to become trapped in the gap. When the piston expands this is pushed out adding to the pollutants expelled. By adding silicon (this acts as an insulator) to the aluminium pistons (hypereutectic) this expansion is greatly controlled allowing much tighter cold tolerances.
Downsides are the pistons are more brittle due to the silicon content and the unabsorbed heat increases in cylinder temperatures, encouraging detonation. Hope that clears things up.

Darren@JDM

iTrader: (53)

Thanks for clearing that up

Still forsale