Earlier this month, high-performance marine engine leader Mercury Racing unveiled a concept small block four-valve automotive crate engine at the Specialty Equipment Market Association (SEMA) show in Las Vegas. According to a press release from the Fond Du Lac, Wis., company, the engine features dual overhead cam shaft (DOHC) four-valve cylinder heads modeled after those used on Mercury Racing’s exclusive quad-cam, four-valve (QC4v) engine platform. Designed to integrate with existing General Motors LS series engine hardware, the unique heads provide a proven high-performance valve train for the robust small block engine design, according to the release.

mercury racing crate engine

The displayed engine features dual overhead cam shaft (DOHC) four-valve cylinder heads modeled after those used on Mercury Racing’s exclusive quad-cam, four-valve (QC4v) engine platform.



“With such positive feedback regarding our exclusive QC4v engine platform and its robust valve train, we felt compelled to explore the adaptation of the four valve DOHC head to General Motor’s popular LS small block V-8,” Rick Mackie of Mercury Racing wrote in his recent blog. “We are anxious to get input regarding our unique small block four valve motor.”

The four-valve design provides improved intake and exhaust flows when compared to conventional two-valve heads, according to Mercury Racing’s engineers. Enhanced port flow enables the engine design to increase maximum power or maintain current power with milder camshaft timings. Valve train durability is also much greater compared to two-valve designs due to reduced mass and, thus, lower stresses.

This is Mercury Racing’s second trip to SEMA. The QC4v automotive crate engine, which was unveiled at SEMA in 2013 and earned a SEMA Global Media Award, will also be featured at the show.

For more information, visit Mercury Racing.

Written by: Matt Trulio
Matt Trulio is the co-publisher and editor in chief of speedonthewater.com, a daily news site with a weekly newsletter and a new bi-monthly digital magazine that covers the high-performance powerboating world. The former editor-in-chief of Sportboat magazine and editor at large of Powerboat magazine, Trulio has covered the go-fast powerboat world since 1995. Since joining boats.com in 2000, he has written more than 200 features and blogs.