Flat-plane Crankshaft

Tom Lieb sat down with LSX Magazine to share his many years of knowledge on flat-plane crankshafts.


There’s a lot of chatter on the internet lately about the new Chevrolet C8 Z06 that is most definitely on the way to the production line. This new Corvette has a lot of hype behind it as people are talking about the possibility of a turbocharged 5.5-liter engine with the addition of a hybrid powertrain. The new model C8 is also thought to possess a flat-plane crankshaft in addition to these new features. While all of these assets are exciting, there is a lot of interest in the flat-plane crank. But what is a flat-plane crankshaft, and why’s it so special?

In 1962 Tom Lieb, the owner of SCAT, ran an auto parts business out of his parent’s garage while he was in college. Over the years, the company has evolved and is now one of the most respected manufacturing companies in the automotive aftermarket.

You might think the flat-plane crank is some wild new technology that GM built in a secret lab, but that’s hardly the case. In fact, the flat-plane design has been around for decades. Cadillac was one of the first manufacturers to use it in a V8 back in the early 1900s. And the flat-plane crank is probably more common than you realize. Just about every four-cylinder in existence utilizes this technology, including that annoying Honda Civic that keeps doing laps in your neighborhood getting into the infamous “V-Tec” mode. But don’t let that guy sway you one way or another — the flat-plane has some uniqueness to it when installed in a V8 engine.

 

Flat-plane crankshafts are often found in both super and hyper-cars — McLarens, Ferraris, Porsches, and Lotus’ are no strangers to this type of crank, and if you want to know what else they have in common, it’s a great exhaust note. The flat-plane crank is responsible for this phenomenon. These lightweight cranks rev higher and faster than the cross-plane crank that most American V8 enthusiasts are familiar with while making a delightful sound that the now-standard cross-plane designs can’t duplicate.

 

Tom Lieb, the owner of SCAT Crankshafts, knows the ins and outs of just about every crankshaft made, including the flat-planes. And while GM does not offer any flat-plane cranks for the LS or LT platforms at this time, we knew Lieb would be an excellent asset to this article since he’s worked with big-name companies to develop flat-planes used in popular hyper-cars. We sat down with Lieb to ask to glean some of his many years of knowledge on these cranks.

Read the full article on the LSX Magazine site.