A minimum of 5 gallons of heated hardening oil are needed to harden connecting rods, crankshafts, front ends, & induction valves properly. Hardening oil should be heated to 90 deg. F. before placing stainless steel bagged items in the drum. After placing the protective bag in the oil, immediately put as many holes in the bag as possible. No hardening will take place if the hardening oil does not touch the bagged items..
