| "Forged pistons are stronger than the stock cast pistons due to the same grain refinement and flow characteristics described with the forged connecting rods. JWT pistons are forged from high-silicon aluminum alloy. Although high-silicon aluminum is not quite as tough and ductile as lower-silicon alloys, it is more dimensionally stable over a wider range of temperature. Because of this, you can run much tighter cylinder-to-wall clearances with high-silicon pistons. This creates a quieter, longer-lasting engine free of piston slap. Ring life and seal is also improved with these tighter clearances. Road racing engines and high-performance street engines are often assembled with high silicon pistons because long service life is important. Low-silicon pistons are best suited to short-duration, extreme-duty events like drag racing, where life and noise are not important and can be sacrificed for toughness. Typically a high-silicon piston can run clearances as tight as 0.0025-inch where a low-silicon piston runs from 0.0040-0.0060-inch. Even though a high-silicon piston is slightly less ductile and tough than its low- silicon brother, it is still considerably stronger than any OEM-type cast piston. The inherent strength of forged pistons will help them withstand the rigors of high boost without nearly as much worry about pinching ring lands or fracturing under the pounding of detonation. This will help us gain reliability even with a high power output. The JWT pistons are also about 50 grams lighter than the stock pistons, reducing reciprocating weight and strain on the connecting rods and crankshaft. JWT pistons are also ground with a tapered barrel shape to the skirts with a slightly offset piston pin to reduce piston slap and the accompanying noise typical of racing forged pistons. These machining tricks also cut down on cylinder wall, piston and ring wear. These pistons are nearly as quiet as OEM- cast pistons in terms of knocking or slapping noise. JWT pistons make use of genuine Nissan or other Japanese OEM-type ring packages. The OEM rings on a typical Japanese piston are low-tension like a racing-type ring for low friction but have several features such as chrome facings that wear much better than your typical moly-faced or iron aftermarket ring domestic engine builders favor. The pistons feature a tapered, thin wall tool steel piston pin for superior strength and about 60 grams less weight than the stock pin. The pins are also slightly shorter so there is no excess unnecessary metal tied up in the length of the piston pin. The pins are retained with reliable double spirolock retainers. These spring steel retainers can withstand much more side load than the stock wire type retainers and are quite reliable--an important feature as you do not want your piston pin to drift loose into the cylinder wall at high rpm."-Sport Compact
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17:43:29 02/21/06
