Spool Nissan CA18 Stroker CrankshaftNissan CA18DET 87. 6mm Billet 4340 Stroker Crankshaft This is a true billet crankshaft machined from Billet 4340 core stock (not a cast forging blank that is final machined). Each crank is machined from core stock 4340 on a CNC machine, then Nitrided and final ground. With the increased cubic capacity from the 87. 6mm m stroker crank, big increases in torque and low to mid range power are achievable. Boost will come on earlier in the rev range and