The engine was easier than the chassis. Castle already had most of the pieces, not to mention an intimate understanding of how they were supposed to work. He made minimal concessions to modernity -- notably a fan to cool the motor and a starter so he didn't have to crank it by hand. But that was pretty much it. He replaced the pistons and bearings. He made a new distributor. He traded some parts for three authentic Miller carburetors and found the fourth, unbelievably, on the wall of a local tavern. "Thank goodness for that," he says. "Otherwise, I would have had to make it myself."
Castle used a handful of off-the-shelf components in the engine, but only after he'd massaged them to the correct dimensions. For instance, he bought valves designed for a modern Mazda engine because the stems and guides were the correct size. "They were the same as the original within two or three thousandths of an inch," he says. "I had to cut the length down and cut the head down and put keepers in. But I wasn't happy with the retainers. I found that I could use the retainers out of an Olds Aurora and machine them down to the diameter I needed."
Nearly five years after beginning the project, Castle was ready to start the engine for the first time, probably, in nearly three quarters of a century. I ask him if he was worried when he punched the starter. "No, not really," he says with a shrug. "We're used to working with antiques that haven't run in forty years. You tear 'em down and you rebuild 'em, and you think nothing of firing them back up again. As long as you've got water and oil circulating..." Terry adds: "An engine's an engine."