Mercury Marine’s New-Concept Small Block

Four-valve engine debuts at SEMA show.

Mercury SEMA

Appearing at the Specialty Equipment Market Association (SEMA) show for the second straight year, Mercury Marine unveiled a small-block four-valve automotive crate engine. The motor features dual overhead camshaft four-valve cylinder heads modeled after those used on Mercury Racing's quad-cam, four-valve engine platform. The heads are designed to integrate with General Motors LS series engines to provide a high-performance valvetrain for the potent small block. Enhanced port flow lets the engine create maximum power or maintain current output with milder camshaft timings. Valvetrain durability is also increased compared to two-valve designs. See more at