These forged 83mm bore pistons are potent. Combine with a 92.8mm crank for 2008cc displacement that makes TORQUE and POWER. This set includes 4 pistons, rings, pins and clips. Wrist pins are 21mm. Compression height is 31.6mm. And, compression ration is a whopping 13.1-1. Supplythe octane and these pistons will deliver grunt all day.