Originally Posted by 95gainfla
you OFFICIALLY know NOTHING about H-series engines.
mahle makes a forged piston specifically for the H and it doesn't require sleeves.
Really? because i have run these so called coated pistions and they have failed... So let me rephrase so you can understand....The only way you will make power reliably, besides using a "stock honda" pistion to raise compression is to sleeve the motor.
Dont get me wrong the h22 is a bad ass motor, tranny sucks ass but the motor is really strong. In JDM compression all motor setup a beast of a motor can be had. JE and CP dont even advertise this "special coating". Mahle is the only one that does and yes they make great pistions. Have you used them in H series sleeves? I have. Just like any other honda i would much rather sleeve and match a forged pistion with known reliable parts....
Btw thew h22 sleeve is made from FRM or fiber reinforced metal. This is also used in the NSX.
Making FRM sleeves goes something like this: First a fiber-based material in the shape of the cylinder sleeve is inserted into the die of the cylinder block. Liquid aluminum is then poured into the die and fuses with the fiber sleeves. Once the block is ready for it, the cylinder walls are machined to the desired bore dimension, leaving only 0.5mm of thickness to the fiber sleeves that cover the cylinder walls.
With the reinforcement the sleeves generate lower friction than traditional iron liners, which translates to improved revolutions, power and reduced wear. In addition the thinner fiber sleeves fortify the block, allowing the distance between adjacent bores to be reduced while maintaining strength and rigidity. There are drawbacks, however. It can be argued that because they are so thin the sleeves were not designed for too much boost pressure, which limits the potential of the stock engine and poses a challenge for us.
Overboring for more displacement is also out of the question since the sleeves are so lean. Even if you machine-off enough material to avoid breaking through to a water jacket, you still have to deal with the softer untreated metal under the fiber layer. For these reasons it is recommended that H22 sleeves never be bored or honed, always replaced.