CP Pistons is one of the most trusted names in the industry, and for good reason. Their extensive shelf catalog provides the user with many of the options that you’d normally be resigned to going to a custom piston for. Their standard offering already includes Dual Pin Oilers – providing double the amount of oil to the wrist pin, radiused valve reliefs and the pin fitting final hone on the wrist pin bore. They even include an Accumulator Groove as a standard option. This provides a small pocket for the combustion gasses to collect after the first ring, reducing ring flutter and providing a better seal allowing more downward force on the piston A.K.A. – make more power. CP Standard Shelf PistonsFeatures

• Dedicated forgings
• Balanced to or 1 gram
• Wrist pins provided at no cost
• Pin fitting provided at no cost
• Accumulator Grooves
• Dual forced pin oilers
• Pick lock grooves
• Fully CNC machined
• USA Made

Pistons come with wrist pins, pin fitted, and locks (except for Subaru).CAM AND BARRELThe Cam is the shape around the skirt of the piston and the barrel is theshape from under the oil ring to the bottom of the skirt. Extensive researchand development has been done to find the optimum skirt shape for eachpiston. These shapes have been found to seal up cylinders and reduceharmonics in the bore better than ever before. Depending on the forging andapplication, different cam and barrel profiles are utilized for maximumperformance. Having the correect cam and barrel on a part promotes thefollowing:1. Tighter clearances2. Less noise3. Better ring seal4. More power5. Increased durabilityANTI DETONATION GROOVES (CONTACT REDUCTION GROOVES)Also know as contact reduction grooves, which limit thepiston/cylinder contact during high temperature and high RPM.These grooves also protect the top ring by disrupting detonationwaves.ACCUMULATOR GROOVEV-shaped groove machined in the 2nd ring land that adds to the volume between the top and second ring. This groove accumulates residual gasses from combustion which alleviates top ring flutter and premature second ring wear, improving ring seal.DOUBLE PIN OILERSDouble Pin Oilers (opposed to single pin oilers), in conjunctionwith our annular reservoir, can add twice the amount of oil fromthe cylinder wall to the wristpin bore. This is a standard option onany piston that receives forced pin oiling.BROACHESBroaches are horizontal slots in the pinbore designed to allow oil to enter between the wristpin and pinbore. Broaches are also used to accommodate the wristpin shape under compression, as it can become somewhat oval and needs room in order to alleviate galling.PIN FITTINGThe pin bore is precision honed to attain an exact pin clearance. Depending onthe application clearances typically range from .0003 to as much as .003between the wristpin and pin bore.