Now That's A Hot Rod - Article
February 24, 2011 12:00 AM
So I handed over shopping bags full of $20 bills and the car was mine. And, it stopped all of that no-hot-rod nonsense I was hearing--in a hurry.
Enter Bernard Juchli, foreman of the "Jay Leno More-Money-Than-Brains Garage." Bernard has built numerous race-winning cars and worked on many projects over the years. He took one look at this project and said, "Just shoot me now."
As if getting this car roadworthy weren't already enough of a challenge, we soon had to replace the engine because somebody had opted to use radiator hose as an oil line. There I am, going down the freeway for the first time. I put my foot into it and boom! That 90 psi of oil pressure was too much for the radiator hose and all 16 gal.--that's right, 64 quarts--of oil was gone in less than 10 seconds. That was the end of that.
Remember, this motor was used in a tank that weighed 92,883 pounds--empty. Fully armed, the tank weighed 101,775 pounds. With 233 gal. of 80-octane fuel in its tank, the Patton would travel about 80 miles. That's about one-third of a mile per gallon.
We added, among other things, rear brakes with vacuum boosters front and back, a new starter motor, an entire new electrical system, rear springs and an electric pre-oiler pump. We even added a Ki-Gas system--like many supercharged cars use--to inject raw fuel and prime the motor before starting. And we have mufflers, so we're socially responsible.
This isn't a car that when you take it apart and drop something you hear bink. You hear, Clunk! Bang! The engine alone weighs 2100 pounds. The car weighs 9500 pounds--nearly 5 tons, but only onetwentieth of what the tank weighed. This thing is faaasssttt. Best of all, it's hilarious to drive. The size is what's the funniest. The engine alone is 6 ft. long. The car looks like a roadster on steroids. When Arnold was on "The Tonight Show," I brought it in to show him. I said, "It's the Terminator car." He loved it.
The engine was originally built under license by Chrysler, and cost the government $110,000 in 1953. Today, a complete rebuild would cost $4500. How's that for re-using the nation's tax dollars?
With the engine handled, we turned our attention to getting all of that power down to the ground. So we replaced the transmission. The one in the car came out of a Greyhound bus. It had about 200,000 miles on it, and it was slipping continuously. So I called my friend Dave Killackey at Performance Allison Transmissions in Azuza, Calif., who pronounced, "There's only one transmission that could do that job: the Allison HD4060 6-speed." We got one from GM Powertrain. I wanted the transmission geared so that when the engine was running at 800 to 900 rpm, the car would be moving about 80 mph. This is an American car, powered by an American tank engine, and the power is being put to the ground by an American transmission, by Allison.
I called the folks at Allison and told them my needs. They, of course, asked, "What vehicle is this for?" When I said it was for a car with an engine from a Patton tank, I was put on hold. I really thought that would be the end of it. But, no, they came back and they were very excited. These people are engineers and they love projects--especially hot-rod projects. We took the car over to General Motors' Proving Ground in Arizona to get it specially calibrated. Steve Spurlin, from Allison, knew just what to do. "When we're through with it," he told me in serious truck-engineerspeak, "it will easily handle your duty cycle."
Since the engine is air-cooled with huge fins and cam-driven fans, it's like driving with your face in a hair dryer. On the coldest day of the year, I'm driving around with short sleeves. People think, "Wow, what a macho guy." But really, macho or not, I have a 100° breeze in my face even if it's 30 below.
This is the only car I've ever had with an engine that can actually overcome the brakes. You put your foot on the brakes as hard as you can and hit the gas, and it still pulls. It's ridiculous how much torque there is. We had to reinforce the frame because it was twisting like a coat hanger. We installed a Rockwell 3.78:1 air-locker rear end, like you'd use on a huge dumptruck. It costs $4200 and it's made of "unbreakabillium." With it, we can really light up the tires, which travel 11 ft. per rotation.
I have aircraft-engine cars, of course, like my Phantom II Rolls with a Merlin V12 from a Spitfire fighter plane, but this is my first tank-engine car. We're branching out. Truth is, this is not that different from an airplane engine. Except that they didn't make a whole lot of gasoline engines for military tanks. The first time someone hit one with a grenade, the Army brass went, "Oh." So tanks went diesel. The Army doesn't use Patton tanks anymore, but I'm using up those old engines. And now the Army has heard about my car. They want me to race it against their tank at Fort Irwin, Calif. My strategy is simple: Just stay out of the way of that gun turret and I'll be fine.
By Jay Leno
Published in the May 2004 issue of Popular Mechanics.
Photos by John Lamm