One of the more amazing things to us is how many small companies pop up to fill niches in the automotive world. Thunder V12 is a small company that builds high performance versions of the old 702ci GMC V12 that was built for trucks and industrial applications in the early 1960s. Huge and thirsty, the engines made more than 600 lb/ft of torque in stock form. No telling what they make with headers, two carbs, electronic ignition, and a “hot” camshaft.
The massive mills have been appearing in stuff like Blastolene’s B702 roadster and various interesting hot rods in recent years. They are visually stunning motors. We don’t know what they weigh, but it has to be well north of 1,000lbs.
Thunder V12 has a pretty large inventory of the engines and various parts (they advertise more than 1,000 pistons in stock) which is good because virtually no one else does. Found in trucks and equipment that was often ridden hard and put away yet, they normally did not age well and since parts are in such short supply, bringing one back on your own is tough business. Hell, find a machine shop that can help you out with a four foot long crankshaft or a block long enough to serve as the base for a kitchen table.
Prices range from $10,900 for an assembled short block in “low performance” form, all the way up to $21,900 for an assembled high performance running engine with a Tremec TKO 600 transmission bolted to it. Yes, ThunderV12 makes adaptor plates to put your “normal” manual transmission behind one os these tug boat engines!
The company has done lots of work to overcome some inherent flaws in the engine like oiling and other issues. They have dyno videos of their 702ci monsters revving to 5,000 RPM and screaming the whole way!
Hit the link below to check out ThunderV12’s site!
I’ve have wondered for a while when a project car was going to show up with one of these for power. Another good site for the GM V-12 is
http://www.6066gmcguy.org/TwinSix.htm
I want to find something to put one into.