Billet Beauty: The Aluminum Cummins That Stole AMSOIL’s SEMA Spotlight

Oil companies usually fill their SEMA booths with bottles, banners, and maybe a race car. This year AMSOIL had a different centerpiece: a Cummins block machined from solid aluminum and set on a shelf next to a row of co-branded Freedom Series oils. It’s the Competition Billet Aluminum block from Fleece Performance Engineering and its in-house engine shop, Freedom Racing Engines. The placard beside it had a simple claim at the bottom: 4,000-plus horsepower capable. That’s a big number, and it tells you a lot about where these two companies are headed together.

Starting From Scratch

The B-series Cummins is one of the toughest production diesels ever built, but it was designed for trucks and tractors, not for drag trucks running absurd boost and fuel. Push a factory cast-iron block far enough and it’ll crack or split. That’s why racers spent years filling, girdling, and deck-plating stock blocks just to keep them in one piece. Fleece came at the problem from the other direction. Instead of reinforcing a production casting, the team machined a competition block from a solid chunk of 6061-T6 billet aluminum.

Aluminum saves a lot of weight compared to iron, and in drag racing every pound matters. Fleece didn’t give up any durability to get there, either. The cylinders get ductile iron sleeves for a durable wear surface, and the bottom end is held together with billet steel main caps and custom main studs. Custom head studs clamp the top end down, which matters when you’re asking a diesel to live with the cylinder pressure it takes to make four-digit horsepower.

Details That Matter

Look closer and you can tell this block was designed by people who actually work on race engines. The valvetrain rides on Jesel tie-bar roller lifters, and the block has lifter service windows so you can get to them without tearing the engine down. Anyone who has pulled a Cummins apart between rounds will appreciate that.

Oiling got the same attention. Fleece reworked the oiling system inside the block and paired it with its own ultra-lightweight billet aluminum dry-sump pan. Up front, a Fleece billet front cover handles dual CP3 injection pumps and houses the dry-sump pump’s gear drive. That’s a clean way to package two big jobs on an engine where space up front is always tight. Topping things off on the display engine was an Apex 5.5-inch turbocharger, which gives you a pretty good idea of how much air this thing is built to move.

The Shop Behind The Block

Fleece was founded in 2008 by brothers Brayden and Chase Fleece. A few years later the company moved to Brownsburg, Indiana, near the heart of the drag racing world, and ended up across the street from an engine shop called Freedom Racing Engines. Freedom became one of Fleece’s best customers, and in 2014 Fleece bought it outright. Freedom kept doing Top Fuel block work alongside its diesel builds, and you can see that nitro experience all over this billet Cummins. Engine Builder magazine named Freedom its Diesel Engine Builder of the Year in 2018. A year later both companies moved into a much bigger facility in Pittsboro, Indiana, where the block is made today. “Race proven, made in America” runs along the bottom of the placard, and in this case it’s more than marketing copy.

Why It Lives In The AMSOIL Booth

The Fleece brothers have run AMSOIL in their race engines for years. Late in 2025, at the PRI Show, the companies made that relationship official with a co-branded line called the Freedom Series. It launched in the spring of 2026 with 10W-30, 5W-40, and 15W-40 synthetic diesel oils, a 15W-50 synthetic racing oil, and an SAE 30 break-in oil. Amsoil handled the chemistry, and Fleece brought real-world data on where high-horsepower diesels fail, with soot control and turbo coking near the top of the list. Fleece VP of Sales Jeff Everett said the partnership let the company shape lubricant design at a molecular level for the first time.

The break-in oil is the clearest link between the two businesses. It was formulated for ring seating and component conditioning in fresh performance engines, and every Fleece Freedom Series long block ships with it. When a builder fires a new engine on oil developed with the company that built it, that’s a partnership that goes deeper than two logos on a bottle.

So the billet block made sense sitting next to those quarts. Most people walking past won’t ever bolt one into their own truck. But it shows exactly what the Freedom Series is meant to protect. AMSOIL gets to prove it’s serious about diesel performance, and Fleece gets its best machine work in front of a whole new crowd. Everyone else got an excuse to stand there and stare at a 4,000-horsepower Cummins for a while.