--- title: "Doubling a Gas Engine’s Compression Ratio Has Chaotic Results" date: "2025-03-26" modified: "2025-03-26" authors: - name: "Ronan Glon" job_title: "Contributing Writer" link: "https://www.thedrive.com/authors/ronan-glon" url: "https://www.thedrive.com/news/doubling-a-gas-engines-compression-ratio-has-chaotic-results" categories: - "News" - "Watch This" --- # Doubling a Gas Engine’s Compression Ratio Has Chaotic Results ![Lada Samara engine with higher compression ratio]() *\Garage 54/YouTube\* Increasing an engine's compression ratio is a proven way of unlocking extra horsepower, but there's a point of diminishing returns. The team at [Garage 54](), the Russian mechanics who [built a V16 using chainsaw engines](), tested this theory by doubling the compression ratio of an old Lada Samara four-cylinder to see what it can take and what happens when you push it too far. Spoiler alert: The results aren't pretty. The first part of the project was pretty straightforward. One of the mechanics removed the cylinder head, which is relatively easy to do on a decades-old Lada hatchback, put clay in the combustion chambers, and reassembled the engine. He then turned the engine by hand a few times to open and close the valves, which left marks in the clay as they moved, and cleverly used the Play-Doh-sculpture-like end product as a reference point. It's not the most advanced or accurate way to measure an engine's compression ratio, but, hey, it worked. Removing 1.25 millimeters of material from the cylinder head and painstakingly welding an aluminum plate to the top of each piston increased the compression ratio from 9:1 to 22:1. The team at Garage 54 felt that was too high, however, so it added a second head gasket to lower it back down to 16:1. And, somewhat surprisingly, the engine started! It's loud, but it's pretty smooth, and it idles stunningly well. https://www.youtube.com/watch?v=hmbRlgeWlhY Next, the moment of truth: Does it drive? Yes and no. It moves under its own power, but the engine self-destructs during an acceleration test, which admittedly didn't require a crystal ball to predict. Parts of the aluminum welded to the piston came loose, and one piston broke in half—even with 100-octane fuel. So, Garage 54 did the sensible thing: It removed the broken piston, increased the compression ratio to 22:1, and stitched the engine back up. This poor Lada is now running a three-cylinder engine with over twice the stock compression ratio. The engine doesn't last long. It starts, runs (if you can call it that), and self-destructs. Interestingly, what kills it isn't the higher compression ratio; it's the knock caused by using the wrong type of fuel. Garage 54 stops there, but it notes that increasing the compression ratio isn't impossible. It simply requires more in-depth modifications, such as upgraded rods. Did it just subtly announce the next part of the project? *Got tips? Send ’em to tips@thedrive.com* ## Author Ronan is a contributing writer for The Drive. He draws on over 15 years of experience to cover breaking industry news, cool one-off builds, and anything in between. He began writing for The Drive in 2021 and stepped into his current role in 2024. His obsession with cars started when a relative gave him a Majorette die-cast shortly after his first birthday. It hasn't flickered since. Ronan lives in France; He swapped Utah's Rocky Mountains, where he grew up, for the Alps. He's an avid hiker, mountain biker, and musician. He also restores classic European cars and mopeds, including a 1978 Citroen 2CV that he's rebuilding from the ground up. ### Author social links [Twitter]()