If you’ve kept an eye on the snarling trucks that race in the deserts of Baja California, Nevada and Arizona, a few key players always come back to the top when it comes to race-winning engine programs.
Names like McCachren and Gordon championing such powerplants have made themselves household names, but the quiet mechanics and machinists behind the scenes propelled them there. Patton Racing Engines has been a staple in unlimited V8 offerings for more than 20 years in the desert. We met with Leon Patton to have a look at the operation and pick the brain of an industry titan.
“I blame the thrill of racing and my adrenaline need. My mother won a 1/4-midget when I was four and half years old, so I started racing at five. Finally in 1984 I started doing engines on the side, by ’88 or ’89 I was doing it full-time,” Patton prefaced. With a young start in racing, Patton had oil in the veins from the beginning. After successfully positioning himself among bright minds in engine technology, he cultivated a very specialized set of skills, skills that would help him develop engines to survive the most brutal racing conditions and engine can see.
“We did the first Trophy Trucks, we turned the ‘Nadeen’ Class 8 into a Trophy Truck, we won a championship with Rob McCachren, then came back with Robby Gordon and won the championship in ’95, and we’ve been doing it ever since,” Patton continued.
What is the basic architecture of your Ford Trophy Truck Engines?
Patton sees the value of resources wielded by OEMs to develop quality parts, and isn’t so quick to dismiss them in favor of aftermarket replacements. While Ford powerplants are the most prominent in the Patton shop, small-block Chevy, LS, and other marques can be found on work benches and dyno.
“We buy raw blocks with no liners and then we make sure they’re up to our spec, sonic inspect them etc. Ford hooked me up with their special casting 20 years ago, we’ve got some of these Ford blocks that we’ve bored out 2-3 times and we’ll bring back years later, put new sleeves in them and start all over. Obviously they’re highly modified, they have huge roller cam bearings, oversized lifters, special liners,” Patton praised.
“Right now we’re still using a version of a 1970 Cleveland head, the ‘Cup guys keep working on them but now they’re starting to move away from them and go with what’s called an FR9 Ford Winston Cup cylinder head. The head is CNC milled to a custom program we have worked with someone to develop specifically for off-road racing.”
A highly recognizable feature to most Patton Trophy Truck engines is the Kinsler eight-stack fuel injection systems. Not only aesthetically cool to the gear head, but offering functionality and tuneability that becomes part of Patton’s secret recipe for success.
“We kind of pioneered that, our claim to fame with eight-stacks. You can throw the truck around, a blip of the throttle will break the rear end loose,” Patton distilled.
How do you keep engines alive racing in Baja?
Desert racing not only subjects engines to some of the worst heat, contaminants and vibrations, but also un-heard of cyclical loads and high-G loads. Desert racecars spend nearly as much time airborne as on the ground, the un-loading and repeated loading of engines and drivelines allowed to spool-up and then hook up in soft sand, rocks and loose surfaces makes for wear and tear no other motorsport can replicate. To improve the survivability of these engines Patton goes to great lengths in design and engineering.
“If you ever watch us assemble one of these, it’s blueprinted unbelievably. We will actually sand and massage bearings to a certain shape, we don’t just say ‘we need .003 clearance,’ it’s elliptical to accommodate the pounding.”
The experience gained to learn these tricks is a mixture of real world scenarios and data collection, even sophisticated machines can’t replicate the conditions. As a result, camshaft grinds, bearing profiles, rotating assembly torsional stress and other factors are unique to the application.
“No other form of racing is close to desert racing, the only thing that comes close is offshore boat racing becuase the get out of the water and rev a lot. Even a spintron can’t simulate that so we started doing a lot of data-logging and we could see the cyclic loads an off-road car goes through. That data introduced us to why we were destroying stuff, and now they’ve ground special lobes just for us. Roush Yates does the same thing for ‘Cup stuff. The way it ends up, there’s some goofy stuff that the cam manufacturer says ‘this is too weird, it won’t work’ but it works very well for our application,” Patton explained.
Typical prep in between races has to be kept in check, with races ranging from 300 to over 1,000 miles in length non-stop, these engines can’t be so high-maintenance that they require extensive rebuilds all the time.
“We do pretty good, even at 860 horsepower we’ll just do a ring and valve job and it’s out the door in a week, ready to run another 1,000-1,500 miles. Knock on wood, we’re the only ones doing that. We get about 2,000-3,000 miles on a set of pistons, then we do a major rebuild. Our competitors are rebuilding every 800-1,000 miles,”Chris and Leon “As long as you keep the water and dirt out of them…” Leon and Son Chris Patton summarized.
How has engine management evolved from carbureted to cutting edge EFI?
“We mostly exclusively use Motec. The M190 is current Trophy Truck computer, the M800 was pretty much state of the art, and back in my day there was the M48 which was pioneered in the early ’90s.” Patton explained.
“We’ve experimented with a lot of people’s knock control over the years, and it’s better than anything we’ve tried. We have the ability to have eight oscilloscopes, one on each cylinder, to watch if there’s any knock. When you see it coming into knock in one cylinder the power would flatten out or start going away.”
“Now with Motec’s knock control we’ve run an 890 horsepower engine on 91 octane and it will individually pick out cylinders to retard at 1/4 degree at a time. With the eight-stack we have control of ignition and fuel at each cylinder, so it’s like eight individual engines.”
Age old arguments: Ford/Chevy and Big-Block/Small-Block
“I’d still say the Fords are number one in popularity for Trophy Trucks, Ford used to put up $50,000 contingency, and still in Best In The Desert if you run a Ford you get a big contingency,” Chris and Leon Patton explained.
The debate whether a big-block or small block is better for an unlimited truck is still developing. Different engine packages have fallen in and out of favor over the years based on the technologies of the chassis and engine builder’s experience.
“Most of the Trophy Trucks are running small-blocks, they’re just toying with big-blocks again. With the advent of four-wheel-drive you need all the torque you can get. We’ve always avoided them since years ago when we were racing against Walker Evans because we could destroy him on acceleration,” Patton concluded.