We're thunderstruck by the insanity that is THOR 24, which is why we're throwing it back to this feature on the custom semi's incredible 27.9-liter Detroit Diesel V-24 engine build that ran in Hot Rod Magazine back in 2011. Marvel and enjoy!

Sept. 2011, HOT ROD Magazine — They say everything's big in Texas. Poppycock. When it comes to truck motors, Lake Havasu City, Arizona, puts the Lone Star State to shame. That's where Mike Harrah has his treasure trove of trucks, cars, bikes, helicopters, and airplanes that makes gearheads drool with envy. His under-construction show truck has 36 butterflies in its 12 injector hats.

Why? "Because I can," Harrah says. There's no reason to take a 24V71 and build an intake manifold that weighs 1,000 pounds and mounts eight 6-71 superchargers on top of four others other than to say: There, take that. Yes, this is a V-24 Detroit Diesel two-stroke (normally used to power ships), which is two V-12 Detroits joined together nose to nose with splined cranks. It adds up to 1,704 cubic inches. It's ridiculous, on a grand scale. And that's why it's cool.

See all 39 photos Sept. 2011 cover of HOT ROD Magazine with THOR 24's twin-V-12 Detroit Diesel engines

Harrah is a trucking and construction businessman who has done very well for himself, and he decided to throw caution to the wind when it came to building his newest toy, a Peterbilt semi-truck meant for the show circuit. The motor is obviously the focal point, and never one to shy away from the spotlight, Harrah went for broke. He claims this thing makes more than 3,400 hp, and there's a fairly popular YouTube video out to prove it, but we're a bit skeptical. It really doesn't matter how much power it makes—the visual is the key. But the torque figure has to be astronomical. Yes, it does run, though the truck itself was nothing more than huge frame rails and a stretched cab when we saw it, so we haven't seen it motor down the road.

The key is the mammoth intake manifold, made from a lot of aluminum plate with trap doors inside to house both the blower drives and the pressure chambers. It's pretty complicated, and Harrah threatened to strangle us if we revealed how it was done—but you can figure it out if you think about it long enough. Credit the ingenuity of builders Tim Spinks and Paul Abram, the project management of Steve Huff, and some fabrication by Harrah himself for this outrageous statement.

Harrah wants to take it on the 2012 Power Tour, which raises the question: How do you see out of the windshield?