Building Mopar's historic Slant-6 engine for Vintage Modified racing

When it comes to making horsepower in stock car racing, the Chevy small block V8 is by far the most iconic racing engine. In terms of the overall number of victories in all racing classes, the competition isn't even close.

But that doesn't mean there aren't a lot of other cool engines that have been a part of our racing history—and a few that aren't even V8's. The Mopar Slant-6 is just such an engine.

First introduced by Chrylser in 1959, the inline six-cylinder engine was an all-new design and quickly became known as the "Slant-6" because the cylinder bores were canted 30 degrees off vertical. The idea was to lower the effective engine height so that it could fit in cars with a low hood line (specifically, the midsize Valiant), but the unique configuration also made the engine instantly recognizable.

While the main purpose of the design may have been packaging, slanting the cylinder bores off the vertical plane also had another, very real advantage. Slanting the engine effectively moved the cylinder head off to one side of the engine bay. This created additional room for intake manifolds with pretty long runners. And it was this difference that allowed for an engine that created more torque than other run-of-the-mill straight six engines made by the OEMs.

So, as you can guess, the Slant-6 was quickly picked up by racers of all stripes, and could even be found in NASCAR's Grand National Series back in the early '60s. The engine made decent power, was easy to find because Chrsyler put them in practically everything, and were about as hard to kill as your household roach.

Chrysler mostly made the engine in two displacements: 170 and 225 cubic inches. The bigger cube configuration obviously was more popular in racing, especially in the configuration with the forged steel crankshaft that Chrysler used up until 1976.

These days you can still find Slant-6 engines racing in all of their overweight cast-iron glory, but only in the Vintage classes. Still, we know plenty of folks that race their Vintage race cars just as hard as the feature-class guys. And we've always loved the throwback thrills of a good Vintage event.

So when we heard our friends at KT Engine Development were putting together a classic Leaning Tower of Power Slant-6 for a local Vintage racer, we stopped by the check things out. Like always, KT Engines weren't planning a run-of-the-mill engine build. They actually cooked up a few tricks to help the Slanty make a little more power while keeping the costs in check and maintaining legality all the while.

Check it out for yourself.

Sources

JE Pistons

714/898-9764

www.JEPistons.com

KT Engine Development

704/784-2610

Smith Brothers Pushrods

800/367-1533

www.Pushrods.net