Installation TipsMcKnight says that proper head gasket installation can make a world of difference when it comes to performance and long-life. He offers a few tips to help ensure your replacement MLS head gaskets deliver the goods.
*Make sure the engine's head and block are flat and smooth. Flatness is checked with a precision-ground straight edge and a 0.002" (0.05mm) feeler gauge. The gauge should not fit under the straight edge when checking the head from end to end and diagonally from corner to corner - Ra readings of 30-80 micro inches are acceptable for the surface finish (compared to the Ra of 7-10 that early MLS gaskets required).
*Don't use abrasive materials to clean the cylinder head before installing the gasket, since this can damage the head. If you're replacing a worn MLS gasket, there won't be any gasket material or facing to remove from the head. So simply ensure the head is flat, then take the gasket out of the package and install it.
*Renew the torque-to-yield head bolts every time. You don't want to accidentally use one that's stretched so far it won't provide the proper load when installed. Remember, you can't tell a good head bolt from a bad one by looking at it, so replace all the bolts. Some torque-to-yield head bolts are available in engine sets from suppliers like Victor Reinz; others must be purchased from OE dealerships.
*Use of 30-weight motor oil is desirable on the threads of the bolt and the underside of the bolt head, unless the engine manufacturer provides instructions to the contrary, or the bolts have been manufactured with a high-tech coating that eliminates the need for additional lubrication.
*Always refer to current information for bolt torque specs for your engine. Even for late-model engines, these are typically revised over time as more information becomes available to the engineers. So check the most recent manual for bolt torques, regardless of the year of manufacture.
*Use a quality torque wrench and torque angle gauge to achieve the correct torque and precision angle of turn when tightening head bolts. Follow the manufacturer's recommended procedure for both sequence and amount of torque and turn. It's extremely important you don't guess the angle of turn since you can damage the head, block, bolts or the sealing of the engine.