ENGPAR Sales Pvt. Ltd. Offers Cam Bushes with Oil Retention Properties. ENGPAR Sales Pvt. Ltd. Supplies piston rings. Cam Bushes with Oil Retention Properties are manufactured from white metal [backed by MS Strip], gunmetal and bimetal [copper lead]. Cam Bushes with Oil Retention Properties are also available with other features which include softness, and its ability to wear off itself and save the expensive cam on sudden breakdowns of the engine. These are available in semi sizes which contain extra metal on the inner bore up to 0.055" above standard size and give the flexibility to mechanics to size the bushes according to their requirements.