Day 30: Engineering and Art

Forged aluminum high compression piston
by Ross Racing Pistons, El Segundo, CA

I admit it. I have no idea how a photocopy machine takes a single sheet of paper from a stack, pulls, pushes, and rolls it into position, imprints it, flips it over, imprints yet something else again, collates it, spits it out,  staples it, and presents it to an impatient onlooker who bristles that it took so long to get his copies. This is Rube Goldberg at his finest!
Hard to fathom that when the internal combustion engine was being thought up some 125 years ago, equally complex machines were already in service. They did not have the benefits of electronic miniaturization, of course, but they were able to apply the laws of physics to turn energy into product in ways that really astound me.

Turning stored antediluvian heat into productive motion is the essence of automotive science. When engineers take something that goes up and down and transform it into something that goes round and round, it is to them simple mechanics. For most of us though, it's as mysterious as those photocopies. So the opportunity to handle, measure, fit, and secure the sundry pieces of cast iron, billet steel, forged aluminum,  brass, and cork-- that's right, old British motors have corks-- is a chance to appreciate one of the mysteries of modern life: the popping, rumbling or humming sounds that emanate from under the hood of a car.

Early automobiles combined the talents of the carpenter, the engineer, and the blacksmith. The latter contribution is in evidence when the internal components of a motor are before you. Large, heavy, and purposeful pieces of metal go back and forth, up and down, or spin at high velocities, ideally without breaking, coming apart, or burning up. To do this effectively, parts are machined to extremely close tolerances and have to manage friction, the expansion effects of heat, and the mechanical displacement caused by centrifugal force. On paper, this is engineering. In one's hands, this is art.

Billet steel crankshaft from Targett Motorsports

One of the largest parts of an automobile engine is the crankshaft. It turns the reciprocal motion of the pistons into rotational motion that suits the requirements of round wheels. The original crankshaft from an MG car looks like something made by a burly Welshman with a big hammer and a bad attitude. It was meant to live a life of leisure tooling the lanes of early 20th century England with an occasional spirited romp in the country or bit of gentlemanly sport on the track. It was not designed for long days of high-speed touring or crossing western deserts in summer. Occasionally they break. Unexpectedly. Rotational motion and any planned progress toward a destination come to a halt. Pretty much, the trip is over. No AutoZone or Pep Boys store will have a crankshaft for a 1952 MG on the shelf. Nor will the typical repair shop in East Jippip be eager to tear into such a project. This is open heart surgery.

Because MG cars have a long racing history and continue to compete around the world, components utilizing modern metallurgy and manufacturing techniques are variously available, though very specialized and somewhat of a cottage industry. Since I only wanted to build this motor once, I decided it was a bit like buying insurance. You can pay now, or you can pay later. But later may be a long way from home.

Left: Original cast connecting rod
Right: New forged steel rod by Saenz

As the parts arrived in the big brown truck over the last few weeks, I marveled at their precision and symmetry. Compared to the stock components, they were truly works of art. Custom made from steel or aluminum forgings, computer-machined to precise profiles, polished and dynamically balanced, I felt a bit sad that once assembled, no one would likely see these objets d'art again. This was truly a Kodak moment! I grabbed the camera. The guys in the machine shop adjusted the lights