Diesel of the Week is presented by
![]()
There’s no shortage of diesel talent out West – we’ve met our fair share of “desert” diesel engine builders who’ve impressed us with their standout builds. Frank Davis of Sin City Diesel & Offroad is one of the recent names that comes to mind. Last year, a Cummins build of his was voted our 2022 Diesel of the Year winner. Being audience elected, our readers were impressed with his cleanly put together compound-turbo 6.7L Cummins Engine.

The Las Vegas shop recently expanded to a 17,500 sq.-ft. space where they provide a number of diesel services like custom tuning, engine rebuilds, turbo upgrades, suspension lift kits, and custom paint. They’ll do just about anything when it comes to customizing 4-wheeled off-road vehicles; they’ve even started a sister company that handles UTV builds.
Almost a year later, and we’ve found another Sin City-built 6.7L Cummins engine to feature in our Diesel of the Week series. This time, it was built for customer Austin Ouellette.

“I had been wanting to do a diesel build and I contacted a friend’s shop to do it for me,” Austin says. “He didn’t really want to do anything with commonrails though, so he suggested I call Frank. Anyways, I put my truck with no engine in it in my trailer and dropped it off to him along with an engine block and a box of parts. He’s done a real good job with it.”
Austin works as a field mechanic in Phoenix fixing up diesel cranes, tractors, and light pickups, and formerly worked in the mines in northern Nevada for Komatsu. He’s no stranger to diesel work, and even built a few “budget” 12-valve builds when he was in the Air Force.

With the long hours and travel associated with his current career, Austin found it best to enlist the help of Sin City Diesel on the build of his 6.7L Cummins powered ’08 Ram 2500.
The engine features a fire-ringed block, ARP 625 head studs, a ported cylinder head, D&J freeze plugs, Wagler Street Fighter rods, D&J tool steel wrist pins, fly-cut factory Mahle pistons, and a Hamilton 188/220 camshaft with flat tappets.
When it came to the turbocharger, Austin decided on a Midwest CRT dual ball-bearing S480, sporting a 96mm compressor wheel and a 1.15 T6 housing. This provides the necessary boost to reach his power goals. The truck was making just under 900 horsepower before the turbo was installed, and Austin bets that number is now somewhere between 1,000-1,200 horsepower.

For fueling, Austin opted for Dynomite Diesel’s 200% over injectors, complemented by two stock pumps – a Cummins lower pump and a Duramax upper pump. To add an extra kick of power, Austin included a Nitrous Express stacker three kit with a 250-hp shot.
“I’m eventually going to go with a single, 14mm fuel pump, but as of right now I’m just leaving it with two stock pumps since we’re still getting all the tuning down,” he says. “It’s not a race truck, just a fun weekend-warrior-type build.”
Diesel of the Week is sponsored by AMSOIL. If you have an engine you’d like to highlight in this series, please email Engine Builder Editor Greg Jones at [email protected].