Jim Hetrick, Lake Forest, CA
Nothing packs quite the visual punch as a big Roots supercharger poking up through the hood of a muscle car. Well, nothing except a set of chromed velocity stacks, that is. The taller, the better, right? Sarcasm aside, the octet of 13-inch stacks jutting up from the intake of Jim Hetrick's Hemi stopped us dead in our tracks at a recent cruise night at John Force Racing in Yorba Linda, California.
This impressive engine sits in a '65 Dodge Coronet that is as nice looking on the outside as it is in the engine compartment. When he bought this car about two years ago, it was in a semifinished state-the paint and bodywork had been done, as well as the installation of the 528-inch Mopar Performance crate Hemi. The previous owner had a cross-ram intake on it, but it wasn't tuned well and the engine ran poorly. No big deal-Jim was looking for something more eye catching.
Hilborn came to the rescue with its Hemi electronic fuel-injection kit. Though Hilborn ships the kit with ram tubes, they were too short for Jim's liking. He would settle for nothing less than 13-inch tubes, so he had a set made out of thin-walled 23/16-inch aluminum tubing. Taller tubes make more torque, Jim says, and his Hemi sends about 710 lb-ft of tire-smoking twist to the ground.
Though it is not included in the kit, the Hilborn EFI package needs either a Mallory or an MSD ignition box to operate. Jim went with MSD. The 6AL box is hidden out of sight. It triggers a Blaster II coil and a Pro Billet distributor. Jim bought black Moroso plug wires and put the MSD ends on them so they would fit the distributor cap.
The intake manifold is available from Hilborn in a variety of finishes, but Jim treated his to a mirror polish powdercoating. Those shiny Indy valve covers look like they're chrome plated, but they're actually polished aluminum. Jim even painted the coil semigloss black to look vintage.
C. Velocity Stacks
Ram tubes, trumpets, call them what you will, they just look cool. As mentioned before, Jim had extra-tall ones made for maximum impact. He tells us the hardest part of the whole build was finding the right rubber balls to fit correctly inside the bell-shaped openings. They had to be red to match the car and the right diameter to fit just inside the openings. "I looked all over," he says. "I went to toy stores and sporting good stores, I experimented with dying green tennis balls red, and I even looked at jai alai balls to see if they were the right size." In the end, he found a guy selling red exercise balls on eBay-the kind you squeeze to build strength in your hands. "He had 24, and I bought all of them. I would have bought 100 if he had that many." Fortunately, the guy was selling them at $1 apiece. He really could have cleaned up if he knew how badly Jim wanted them.
The Hilborn kit comes with GM fuel injectors. The system operates on 50 psi of fuel pressure provided by an inline Weldon pump mounted downhill from a trunk-mounted fuel cell.
OK, who are we kidding? In spite of the majorly cool Hemi beneath it, the real treat here is the eye-popping Hilborn individual-runner electronic-fuel-injected intake setup. Hilborn ships them fully assembled and ready to bolt on. Jim opted for the version with Hilborn's Carabine ECU, an easy-to-tune engine management system that relies on just a throttle position sensor, a coolant temperature sensor, and a crank trigger. Hilborn engineers set up each ECU prior to shipping based on their customer's particular application, and minor fuel delivery changes can be performed by adjusting a set of potentiometers on the face of the ECU's box once the kit is installed.
A 426 Hemi is a great engine, so the 528 crate engine from Mopar Performance must be better, right? It is a formidable package indeed: a heavy-duty block with siamesed bores, a 4.15-inch-stroke forged-steel crankshaft, 4.50-inch-bore forged pistons, a 10.0:1 compression ratio, aluminum heads, and a custom-ground cam. Right out of the box, this combination is good for 640 hp and 612 lb-ft. We suspect it's not even working that hard to make those numbers, either.