A 1,000-HP DIESEL IN A MILITARY WRAPPER

Steve Ortner, of Belleville, Michigan always wanted a Hummer. When he did finally get the chance to buy a ‘94

Civilian-spec Hummer H1 he was quite overjoyed. But, there was a problem. “The Hummer had a naturally-aspirated 6.2L engine in it, and it was so, so slow.” says Steve. “There were times on hills you didn’t think it would make it up to the speed limit!” laughs Steve. For sure he had the

vehicle he’d always wanted, but it was powered by the wrong engine.

12V TRANSPLANT

“I’d always liked stuff with power and reliability, so the 5.9L 12-valve Cummins was an obvious choice.” says Steve. After acquiring an engine from a Fed-ex truck, he was off to the races. Since Steve knew he wanted a lot of power, he started with the engine block and worked his way up. The Cummins block was fitted with 14mm ARP main studs and a girdle that is based on a Industrial Injection Gorilla Girdle, but was modified at Steve’s machine shop, Mountain Machine. He kept the factory crank, but added connecting rods from Wagler Competition Products, along with Diamond pistons. A 188/220 camshaft from Hamilton Cams was added, and the block was machined to accept 14mm head studs. After the bottom end was assembled, Steve opened up the Hamilton Cams catalog again for one of their Street heads, along with a valvespring package, and pushrods.

COMPOUNDS

While a single turbocharger would have been the easy way to go, Steve was more concerned with response and power so compounds it was. With a high rpmcapable engine, Steve went with a 66mm

Performing a Cummins swap is hard enough, but Steve went the extra mile and built his 5.9L 12-valve for monster power. The engine makes an estimated 1,000 hp and 1,700 lb-ft of torque through a GM 4L80E to the Hummer’s all wheel-drive system. Since the Hummer came from the factory with a diesel, there was a decent amount of room for the swap. Many parts like the engine mounts and transmission adapter were made in Steve’s own shop, Mountain Machine. Reliability was priority number one, so Steve reinforced his engine everywhere he could, with ARP studs in the mains, the rods, and of course the head. Steve went a little further with the head studs, and chose ARP’S Custom Age 625 material in order to prevent any issues at high boost.