Why Chevy Still Uses Pushrod Engines (While Other Brands Moved On)

Even with all of its blunders over the years, one thing about General Motors that we can't really fault is its lineup of small block V8 engines. These engines have been especially central to Chevy's performance lineup. Stuff like the LS and the more recent LT family have proven themselves in production cars, older models that were discovered to be excellent tuning platforms, and crate engines for completely custom builds.

One common thing among General Motors powertrains of the small block V8 variety — and in some cases other layouts — is that they don't use single or dual overhead camshafts, like most modern engines do. While the pushrod, or overhead valve layout, sometimes called OHV, has long been shunned by most OEMs, General Motors is still pushing through with pushrod engines, even today.

A good reason for that is simplicity. Pushrod engines simply have fewer parts than SOHC or DOHC engines, and that simplicity often means a significant increase in reliability. This is why it continues to be such a popular powertrain for engine swaps, and one of the reasons why the LS can handle so much power. That being said, there's a little more to it.

Sure, simplicity is a notable benefit of OHV engines, but they do have some other upsides that make them more suitable for different applications. One such application is low-end torque, a necessity in pickup trucks and other vehicles that need a big burst of power low down in the rev range. This is one of the reasons why the optional EcoTec V8 engines in the modern-day Chevrolet Silverado are pushrod units.

More often than not, pushrod engines have only two valves per cylinder. This means that even at low revs, when there's not a lot of air going into the engine, the air can get to the combustion chamber faster than usual, meaning more power lower down in the rev range. Of course, this comes at the cost of being able to rev high, which is why pushrod engines don't — and can't — have particularly high redlines.

That's a big downside of the pushrod layout: you don't really have a lot of revs to work with. The design of a pushrod V8 also means that, in stock form, a lot of them don't produce much power relative to their size, and stuff like variable valve timing is a no-go. Despite having a few drawbacks compared to modern engine layouts, overhead valve powertrains definitely have a reason to still be around. Even the modern-day base Corvette Stingray still uses a pushrod V8 dubbed the LT2.