No one takes the saying “go big or go home” more literally than automotive enthusiast, developer and philanthropist Mike Harrah — and his latest creation is the most jaw-dropping engine build we have ever seen.
Mike Harrah, whose California-based company Caribou Industries Inc. has made him one of the most successful automotive entrepreneurs on the West Coast, is also well known for his massive contributions to charities across Orange County. But he also goes extremely large with his vehicle and engine projects — and his latest creation does not miss to shock.
The Build — 24 Cylinders, 12 Blowers, 36 Butterflies
Harrah introduces this engine as the biggest ever built for a semi-truck — and we have absolutely no reason to doubt him. The concept is breathtakingly simple in its audacity: take two V12 Detroit Diesel engines, join them nose-to-nose with splined cranks, and mount superchargers on top until you run out of room.
| Engine Configuration | Detroit Diesel V24 (two V12 units joined) |
| Total Displacement | 1,704 cubic inches (~27.9 litres) |
| Cylinders | 24 |
| Superchargers | 8 × GMC 6-71 blowers (some sources: 12 blowers) |
| Throttle Bodies | 36 butterflies across 12 injector hats |
| Engine Weight | ~1,000 pounds |
| Rated Power | 3,400–3,800+ HP |
| Dyno Result | 3,424 HP confirmed |
| Application | Custom-built 359 Peterbilt semi-truck |
| Chassis Length | 40 feet |
| Location | Lake Havasu City, Arizona, U.S.A. |
On the question of why he built the 24-cylinder engine, Harrah’s answer was characteristically direct: “Because I can.”
The Monster in Action
The completed engine sits in a custom-built 359 Peterbilt semi-truck, which required a massive 40-foot chassis just to accommodate the engine and all its supporting hardware. As for the turning radius — your guess is as good as ours.
As they say: “Everything is big in Texas! Poppycock.” Lake Havasu City, Arizona, is where Big Mike Harrah keeps his extraordinary treasure of cars, trucks, bikes, airplanes and helicopters — and this 24-cylinder, 1,704 cubic inch monster is undoubtedly the crown jewel of the collection.
Watch — The 24-Cylinder Engine Running