Even Planes Are Not Safe From An LS Engine Swap, Apparently

You can LS swap almost anything. Enthusiasts have stuffed one of the General's LS engines in just about every kind of car you can think of: Volkswagen Beetles, old Porsches, DeLoreans, and everything in between. If it has a place to put an engine, there's a good chance someone's put an LS in it. Apparently, some aviation enthusiasts are even LS-swapping planes and not only can it work, it sounds awesome when it does.

Now, of course, dropping an LS V8 into an airplane is a bit trickier than doing so in, say, a Miata, especially since you can even buy Miatas that have already been LS-swapped. Planes and cars have very different engine requirements, so very specific modifications are needed to make a piece of small block American muscle carry you through the sky. Despite that, many enthusiasts still feel that it's worth the work, like pilot Len Baxter, who, per Kitplane Enthusiast, LS3-swapped his homebuilt Velocity XL airplane. But why use an LS instead of a normal aircraft engine?

One of the main reasons LS engines are used in so many vehicle projects is their size. GM's family of small block LS V8 engines is famous for combining compact dimensions with power and efficiency.

One of the most common LS engines used in aircraft swaps is the LS3, since it comes in a variety of configurations to fit most buyers' needs and is pretty affordable. The standard LS3 is a 6.2-liter V8 that makes 430 horsepower at 5,900 rpm, but GM offers five other crate engine configurations, for higher revs, flatter torque curves, or higher power outputs. While none of those applications necessarily works for airplanes, builders can pick which one suits their needs best and then modify it from there.

Since GM has made about a zillion LS engines, parts are available everywhere. If you need to make an emergency landing due to engine trouble, there's probably an Autozone within walking distance of where you land that has the part you need. In the case of Baxter's LS-swapped Velocity, he even utilizes GM's cylinder deactivation system and actually runs his engine as two V4s, with two separate electronic control units. So if there's an issue with one or two cylinders or valves, he can actually shut half of the engine down and use the other half to safely get him to the ground.

However, the LS family of engines is proven, durable, and reliable. Which is why companies like Adventure Aviation West LLC are so confident in the LS3 that they created an engine swap kit. The kit isn't cheap, at $62,995, but it claims to be plug-and-play kit, ready to bolt to your airframe. 

You don't necessarily have to modify an LS much for it to work in an airplane, even if you should. In a video from Cleetus McFarland, an RV7 kit plane owner swapped its original Lycoming four-cylinder engine for an LS1 V8 and it's a pretty direct engine swap. The main modifications were the elimination of its stock air-conditioning system to shave 70 pounds, and the addition of a gear reduction box.

The latter is necessary for all LS airplane swaps, since propellers shouldn't spin at the 6,000-plus-rpms that the engine can spin. So propeller reduction units, which are essentially gear reduction boxes, are mounted between the engine's flywheel and the propeller, to drop the prop's speed to no more than around 2,500 to 2,700 rpm. Engine speed is also kept to just around 4,500 rpm maximum, with a cruising rpm of around 3,000. 

In Baxter's case, with his pusher plane-style (prop at the rear) Velocity XL, more modifications were needed to improve cooling, airflow, and efficiency. While it was quite a bit of work, it seems worth it now that he gets to fly something that sounds like a World War II fighter plane.  

Does that mean every personal aircraft owner should immediately jump to swap their engine for an LS V8? No, it doesn't. Aircraft engines are specifically designed for continuous flight at high altitude. While LS engines are reliable, they weren't originally designed for anything other than automotive use. 

So experienced mechanics and engineering, along with very high-quality modifications, are necessary to make an LS-swap safe and dependable. But when professionals engineer and install the engine correctly, LS-swapped planes can be awesome and sound like Corvettes ripping through the sky.