INSIDE FLEECE PERFORMANCE ENGINEERING’S NEW CUMMINS PERFORMANCE SERIES HEAD

BY MIKE MCGLOTHLIN

Just like any short-block build, your cylinder head is only as good as the machine shop that put it together. Proper inspection, precision machining via state-of-the-art equipment, a good valve job, and the company’s track-record in the industry all factor into the deal—especially if you’re chasing four-digit horsepower. For ’03-present Cummins owners looking to go big, there is a lot more to it than simply adding head studs. The factory, crack-prone valve seats need to be addressed before they become a major problem, stiffer valve springs need to be added to handle elevated rpm, drive pressure, and boost, and fire rings are requisite for utmost combustion sealing.

Based on the head work it was regularly performing for its truck pull and drag race customers, the folks at Freedom Racing Engines—the engine building wing of Fleece Performance Engineering—decided to offer a competitionready cylinder head for 24-valve Cummins owners. Called its Performance head, each reconditioned unit comes loaded with some of the best components available in the aftermarket, along with its factory weak links addressed.

Items such as Hamilton Cams’ 103-lb valve springs and Manley Performance stainless valves come standard, as do heat-treated, oversize valve seats, screw-in freeze plugs, fire-ring grooves and the corresponding head gasket. Better yet, Fleece has them on the shelf and ready to ship at all times. While Fleece rates its Performance head for 1,100-rwhp, similarly built units have been used on engines making more than 2,000 hp. From usable core to finished product, join us for a look at the in-depth remanufacturing process each Performance head undergoes