I used to read more car magazines than I do now. the engineering and advancements of vehicles always interested me so when I read articles about the technology and durability testing of the GM Atlas 4200 in 2001 or 2002 i became a big nerd for these engines. An american all aluminum I6 with DOHC drive by wire nearly 300hp and as much torque was pretty cool even when compared to V8s of the time. I remember reading about millions of miles of testing brutal off road racing of the engines. I thought these motors were really cool and maybe I was the only one. Then much later an article in Car Craft made me think I wasnt the only one. A 470hp atlas in a 69 Firebird.
Years passed and I forgot about Inline 6 engines. I started becoming a bit obsessed with another The ford barra motor after seeing Australians making big power on stock motors. I began to learn about the advanced design of these things and began to lust after one. A turbo barra powered fairmont wagon would be such a fun daily driver and sleeper street car.
This led me to wonder if there might be an alternative to waiting until I was rich and could afford to ship over the oceans a container of junkyard barra engines. I thought about the Atlas again wondering if an Atlas could make 600hp and began comparing the barra and the atlas. Turns out I was missing some cool pieces of the high performance Atlas story.
Before the Trailblazer SS got an LS they were considering a twin turbo Atlas and went so far as to produce a concept using shorter rods piston squirters and low comp pistons as well as the mentioned twin turbos adding a water to air intercooler the motor produced 400hp and 400ft/lb and rushed the trailblazer to 60 in 5.35 seconds and a 1.4 mile in 13.9 seconds.
In 2000 GM had Falconer buld a 5 liter version that produced 600hp and the engine went in to a trailblazer looking truck and raced the baja 500 and 1000 and also won overall in 2000 at pikes peak.
So there isnt really an ending or conclusion to this story. I still dont have a barra or an atlas nor do I have any car one of these might go into. I am back where I started wanting a turbo I6 and dropping it into a sedan or wagon, but at least I know I am not so crazy thinking a high powered atlas is a good idea!
In the meantime I will be stalking ebay and LKQ and other greasy places looking and dreaming about Barras and Atlas engines.
Check out this article to learn more about the history and development of the GM atlas engine