ScienceofSpeed

This has been discussed in significant detail in other threads. I wanted to take the time to provide some details and descriptions of these parts.

As you are likely aware, the factory Honda S2000 block uses a special fiber reinforced metal (FRM) cylinder liner that allows increases in strength and heat transfer capacity.

Honda's description:
FIBER-REINFORCED METAL CYLINDER LINERS
Instead of cast iron, the Prelude engine block's cylinder liners are made of a metal-matrix composite material Honda calls fiber-reinforced metal (FRM). FRM is a mixture of carbon fiber and aluminum oxide that, when used in cylinder liners, offers several advantages over conventional cast-iron liners. For example, FRM liners transfer heat to the cylinder water jackets more rapidly. This allows engine designers to build a smaller, more compact engine and cooling system. The designer may elect to keep the same size engine, but increase its power output. Honda engine designers elected to keep engine size and power output fixed and utilize FRM's superior heat-transfer capabilities to increase engine durability. Since FRM is a ceramic-based material (aluminum oxide is a ceramic used for spark plug insulators), it also exhibits higher wear resistance than cast iron. This results in potentially longer engine life. Finally, FRM liners weigh less than cast-iron liners, thereby helping to minimize engine weight.

This cylinder liner is not compatible with traditional aftermarket piston material and coatings.

Mahle Motorsports manufactures forged pistons using a proprietary skirt coating that is compatible with the FRM cylinder liner. These pistons are available in lowered compressions ideal for forced induction applications over 400 whp. Many customers have elected to lower compression with thicker head gaskets only to find that this changes the combustion efficiency. These flat top pistons keep the piston crown height in the ideal location. These forged pistons are approximately 50 grams lighter than a factory piston - weight has been reduced not only in decrease of dome volume but also through pockets in the forging.

The pistons are compatible in either F20 2.0L and F22 2.2L engines with factory or aftermarket connecting rods. They are also available in the factory 87mm bore size as well as 87.25mm. 87.25mm would be used when the bore needs to be honed due to scratches. We recommend that most used blocks use the 87.25mm size unless either the block is new, has no scratches, and the bore is in perfect circle.

The following four pistons are offered:
standard bore size (87mm)
enpp-2031: F20 8.9:1 CR or F22 9.5:1CR
enpp-2033: F20 9.5:1 CR or F22 10.1:1 CR

.25mm over bore size (87.25mm)
enpp-2032: F20 8.9:1 CR or F22 9.5:1CR
enpp-2034: F20 9.5:1 CR or F22 10.1:1 CR

for more information:
http://scienceofspeed.com/products/engine_.../Mahle/pistons/

regards,
-- Chris

leo520

nice....
how much boost can i run with F22 10.1:1 CR

??

siadam

It's not the boost pressure, it's the heat generated by the amount of power you make.

I'm looking for 700whp on 30lbs w/these pistons.

ABCVTEC

It's awesome that these are finally developed. But no NA CR's available?

spectacle

Kudos to these being in development. Never liked the idea of having to sleeve the block

CaseyGW

there are. they even have them to use ap1 rods with ap2 crank = 9k+ rpm safe 2.2

look in the NA section, user wadzii

m R g S r

nice im gunna have to pick up a set of these soon

Irishflame27

i wish i didnt have to sleeve my block

such a fantastic alternative to the headgasket....

TRBOKEV

Is your block so bad that you can't use the oversize pistons?

Irishflame27

yea 3 sleeves were ovaled