PREVENTABLE LIFTER CLATTER
The lifter oil feed hole on common GM LS lifters is offered in more than one orientation. Both are functionally correct and interchangeable. The difference is in the location of the oil feed hole. Both should be installed such that some oil will always remain in the lifter after the engine is shut-off to help prevent lifter clatter when the engine is restarted. This is not an issue with both designs, as one has side oiling and can be installed with the hole pointing in either direction. The other, the traditional GM roller lifter used for many years in Chevrolet V8 and V6 applications, most be installed with the oil feed hole pointing up towards the intake manifold. If installed with the oil feed pointing down, towards the exhaust manifold, oil will bleed out and the lifter may clatter until sufficient oil pressure is present to refill the lifter.
Engine Pro Tech Committee with special thanks to Elgin Industries.
March, 2024
