When you walk up to a small airplane at your local airport, you might hear the propeller spinning and smell the fuel in the air. But hidden under that metal cowling sits the heart of the aircraft, the engine that makes everything possible. For decades, two companies have built most of the engines that power small planes across America: Continental and Lycoming. 

Lycoming powers more than half the world's general aviation fleet, with Continental serving as the other major piston engine manufacturer dominating the remainder of the market. These two brands have been competing and improving their designs since the 1920s. 

Pilots, mechanics, and aircraft owners have strong opinions about which one works better. Some swear by one brand, while others defend the other with equal passion. 

The truth is that both companies make excellent engines, but they do things differently. Understanding these differences helps you make smarter choices about maintenance, buying a plane, or simply knowing what's under your cowling.

Key Takeaways

Continental and Lycoming both make reliable aircraft engines for small planes, but they have different designs. The main difference is where the camshaft sits inside the engine, Continental puts it below the crankshaft, while Lycoming puts it above. This affects how oil drains and how the engine handles sitting unused. Continental engines often feel smoother and start easier when hot, but Lycoming engines typically last longer between overhauls (about 2,000-2,400 hours compared to 1,500-2,000 hours). Overhaul costs run $20,000-$35,000 for most models. Both brands power popular planes like Cessna 172s and Piper Cherokees. Your best choice depends on which plane you fly, how often you fly it, and what kind of maintenance support you have nearby.

FeatureContinentalLycoming
Camshaft LocationBelow crankshaftAbove crankshaft
TBO (Typical)1,500-2,000 hours2,000-2,400 hours
Overhaul Cost$20,000-$35,000$25,000-$35,000
Common IssueCylinder cracksCam corrosion when inactive
Hot StartingEasier (fuel return system)More challenging
Popular inHigh-performance singlesTrainers and mid-power aircraft
Market ShareStrong in 300+ hp rangeDominates 150-200 hp range

 

Why Aircraft Engines Are Important

Your car engine might fail on the highway, and you can pull over to the shoulder. An aviation engine doesn't have that luxury. When you're flying at 8,000 feet, the engine must keep running smoothly and reliably. This is why aircraft engines receive so much attention and care.

Small planes use piston engines, similar to car engines in some ways. They burn fuel, move pistons up and down inside cylinders, and turn that motion into power that spins the propeller. But aircraft engines face tougher conditions than car engines. They run at high power settings for hours at a time. They operate in thin air at altitude where there's less oxygen. They experience extreme temperature changes as planes climb and descend. They sit unused for days or weeks between flights, which can cause internal parts to rust.

The reliability of these engines matters for obvious safety reasons. But it also affects your wallet. A new aircraft engine can cost $60,000 to $100,000 or more. An engine overhaul typically runs $25,000 to $35,000 for common four-cylinder models. These are significant expenses for any pilot or aircraft owner.

Engine design influences how a plane performs too. The cylinder arrangement affects how smooth the engine runs. The fuel system determines how easy the engine starts in different conditions. The cooling design impacts how well the engine handles hot summer days or high-altitude airports. Even small differences in weight matter because every pound affects how much fuel and passengers you can carry.

General aviation depends entirely on these engines. Flight schools need reliable trainers that start easily and run economically. Charter operators need engines that can handle daily flights without constant maintenance. Weekend pilots need engines that don't corrode when the plane sits in a hangar for two weeks. Understanding what makes a good aircraft engine helps you maintain it properly and get the most value from your investment.

Both Continental and Lycoming have spent nearly a century perfecting their designs. They've learned from millions of flight hours and thousands of engines. They've addressed problems, improved reliability, and responded to pilot feedback. The result is two different approaches to the same goal: building engines that keep planes flying safely.

 

Meet the Two Big Engine Brands

Continental Motors started making engines in 1905, long before airplanes were common. The company built car engines in Detroit and became the world's largest automotive engine manufacturer during the 1920s. When aviation started growing, Continental saw an opportunity. In 1929, they formed the Continental Aircraft Engine Company and built their first aviation engine, the A-70 radial. This seven-cylinder engine produced 170 horsepower and powered some of America's earliest mail planes.

Continental found real success with smaller horizontally-opposed engines. The A-65 engine became famous when paired with the Piper J-3 Cub in the 1930s and 1940s. This combination made flying affordable for regular people and helped launch the sport aviation movement. During World War II, Continental ranked 38th among U.S. corporations for wartime production. After the war, they focused on improving their designs for civilian aviation.

The company changed ownership several times over the decades. Teledyne bought Continental in 1969. Then in 2010, AVIC (a Chinese government-owned aerospace company) purchased Continental for $186 million. Today, the company operates as Continental Aerospace Technologies, or TCM for short, and builds engines in Mobile, Alabama. They make everything from the small 100-horsepower O-200 to the powerful 350-horsepower IO-550 models.

Lycoming also started outside of aviation. The company traces its roots back to 1845, though the early history is unclear. Originally called Demorest Manufacturing Company, they made sewing machines and bicycles in Williamsport, Pennsylvania. After becoming Lycoming Foundry and Machine Company in 1907, they expanded into automobile engines. When Charles Lindbergh flew across the Atlantic in 1927, it inspired many companies to enter aviation. Lycoming built their first aircraft engine in 1929—the R-680 radial that produced 200 horsepower.

By the 1950s and 1960s, Lycoming had developed their famous horizontally-opposed engines. The O-320 became one of the most successful aircraft engines ever built. First certified in 1953, it still powers new planes today. The O-360 followed and proved just as popular. By 1961, Lycoming was producing 600 to 700 engines every month. The company became part of AVCO in 1939, and Textron later bought AVCO in 1985. Lycoming remains a Textron division today.

Lycoming has built more than 325,000 piston engines over the decades. They power more than half of the world's general aviation fleet. From the small O-235 in training planes to the massive eight-cylinder IO-720 producing 400 horsepower, Lycoming offers engines for almost every light aircraft application. Their factory in Williamsport still manufactures engines using designs that have proven themselves over millions of flight hours.

Both companies serve the same market but with different corporate philosophies and design choices. Continental tends to offer more variety in fuel systems and configurations. Lycoming focuses on proven designs with longer times between overhauls. Understanding each company's history helps explain why their engines work the way they do.

What Makes One Engine Better for Some Planes?

The biggest technical difference between Continental and Lycoming engines sits hidden inside the crankcase. The camshaft controls when the valves open and close to let air in and exhaust out. Continental puts this camshaft below the crankshaft. Lycoming puts it above. This might seem like a small detail, but it affects how the engine behaves in important ways.

When a Lycoming engine shuts down, oil drains off the camshaft first because it sits at the top of the engine. The camshaft and lifters (the parts that push on the valves) sit exposed to air inside the crankcase. Over days or weeks, moisture from the atmosphere can enter through the crankcase breather. This moisture can cause rust on these steel parts. When you start the engine again, the rusty spots flake off and damage the camshaft. Mechanics call this "spalling." The O-540 and other Lycoming models are famous for this problem when planes sit unused.

Continental's lower camshaft position means oil drains more slowly, though it still drains eventually. Continental engines can develop corrosion too, but it happens less often. This design difference explains why Lycoming owners must fly regularly to prevent cam problems. If you only fly once a month, a Continental might give you fewer headaches.

The fuel injection systems also differ. Continental developed their own fuel injection design. It includes a fuel return line that sends unused fuel back to the tanks. During hot starts (when the engine is heat-soaked after sitting), you can run the boost pump with the mixture at idle cutoff. This circulates cool fuel through the system and purges vapor locks without flooding the cylinders. Continental engines start more easily when hot because of this feature.

Lycoming engines typically use the Bendix RSA fuel injection system, which doesn't have a fuel return line. Hot starts can be trickier because you can't circulate fuel without sending it into the cylinders. Some newer Lycoming installations added fuel returns, but most don't have them. This matters on hot summer days when you land for fuel and need to restart 15 minutes later.

Carburetor placement makes another difference. Continental mounts the carburetor on a "spider" manifold at the bottom of the engine, away from heat. This makes carburetor ice more likely in certain conditions. Lycoming bolts the carburetor to the oil sump where hot oil warms it. This natural heat helps prevent ice formation, though pilots still need to stay alert.

Both companies offer different cylinder designs. Continental makes both parallel-valve and angle-valve cylinders. Parallel valves are easier to service—you can change a cylinder without removing as many parts. Lycoming mostly uses one cylinder design across their models. Continental cylinders have historically suffered more cracks and head-to-barrel separations. Lycoming cylinders tend to last longer between top overhauls.

The TBO (time between overhaul) differs between brands and models. The Lycoming O-235 offers an impressive 2,400-hour TBO, the longest in the industry. Most Lycoming engines run 2,000 hours between overhauls. Continental engines typically range from 1,500 to 2,000 hours, depending on the model. The Continental O-470 in older Cessna 182s was rated at 1,500 hours, though many operators extended this with careful maintenance.

Some pilots report that Continental engines run smoother and quieter. Others say Lycoming engines feel more solid and reliable. These perceptions are subjective and often based on limited personal experience. Both brands make excellent engines when you maintain them properly and fly them regularly. The "best" engine depends on your specific airplane model, flying habits, and maintenance preferences.

Continental vs Lycoming Aircraft Engines: Key Differences Explained

When you park two small planes side by side, one with a Continental under the cowling and one with a Lycoming, they might look almost identical from the outside. Both have cylinders arranged horizontally opposite each other. Both spin propellers at similar speeds. Both burn the same 100LL aviation fuel. But open those cowlings and look inside, and you'll find important differences that affect how these engines run, how long they last, and how much they cost to maintain.

The Camshaft Location Makes All the Difference

The single biggest design difference sits deep inside the crankcase. The camshaft is a metal shaft with bumps (called lobes) that push open the intake and exhaust valves at exactly the right moment. This timing allows air and fuel into the cylinder and lets exhaust gases out. Every piston engine needs a camshaft to run.

Continental places the camshaft below the crankshaft. The crankshaft is the main rotating shaft that the pistons push on. Lycoming places the camshaft above the crankshaft, right up near the top of the crankcase. This might sound like a minor detail, but it creates a cascade of effects that every pilot and mechanic needs to understand.

When you shut down a Lycoming engine after a flight, the hot oil coating the camshaft and lifters drains down into the oil sump within minutes. The camshaft sits exposed to air inside the crankcase. Aircraft engines have breather tubes that vent the crankcase to prevent pressure buildup. These breathers also allow outside air (and moisture) to enter.

Here's what happens when a Lycoming engine sits unused:

This problem hits Lycoming owners hardest when they fly infrequently. A plane that sits three weeks between flights gives plenty of time for moisture to cause damage. Flight schools that operate daily rarely see camshaft problems. Weekend pilots who fly twice a month face higher risk. The O-320 and O-360 models particularly need regular operation to stay healthy.

Continental engines put the camshaft below the crankshaft. Oil still drains off eventually, but gravity works more slowly. The camshaft sits in a position where residual oil provides more protection. Continental engines can develop corrosion too, especially in humid climates. But mechanics report seeing fewer catastrophic cam failures in Continental engines compared to Lycomings. The O-200 and O-470 handle irregular flying schedules better than their Lycoming counterparts.

This doesn't mean Lycoming engines are bad. It means aircraft owners with Lycoming engines need to fly more frequently. Many mechanics recommend flying at least once per week, with each flight lasting long enough to get the oil temperature up to 180 to 200 degrees Fahrenheit for at least 20 minutes. This heat boils off any moisture that accumulated inside the crankcase.

Some owners add CamGuard to their oil. This additive provides extra corrosion protection for engine internals. It costs about $25 per oil change but can save thousands in premature cam replacement. Other owners avoid using sump heaters in winter because these heaters can actually make the problem worse. The heater warms the bottom of the engine, causing moisture to rise and condense on the cold camshaft at the top.

Fuel Injection Systems Work Differently

Both brands offer fuel-injected engines, but the systems work in different ways. TCM (Teledyne Continental Motors) developed its own fuel injection design that includes a return line. This line sends unused fuel back to the fuel tanks. During hot starts, when the engine has been sitting in the sun and the fuel lines are heat-soaked, a pilot can run the boost pump with the mixture at idle cutoff.

This technique circulates cool fuel from the tanks through the entire system, pushing out hot fuel and vapor. The returned fuel goes back to the tanks instead of flooding the cylinders. After 30 to 60 seconds of circulation, the pilot can then start normally. Continental owners report much easier hot starts because of this feature.

Most Lycoming fuel-injected engines use the Bendix RSA system. This design has no fuel return line to the tanks. When fuel gets hot and vaporizes in the lines, you have limited options. Some pilots try various priming techniques. Others simply wait 30 minutes for the engine to cool naturally. The O-540 and IO-550 models can be particularly challenging to start when heat-soaked.

Some newer Cessna installations added fuel return systems to Lycoming engines, but most don't have them. This difference matters most on hot summer days. You land for fuel, shut down for 15 minutes, and then need to restart. The Continental typically fires up on the first try. The Lycoming might require several attempts and specific techniques.

The fuel injection systems also affect how the engines run at different power settings. Continental's design tends to run smoother at lower fuel flows. Pilots report that Continental engines idle more smoothly and run more quietly at cruise rpm. Lycoming engines feel slightly rougher but deliver excellent performance throughout the power range.

Carburetor Designs Create Different Ice Risks

Many engines still use carburetors instead of fuel injection. The carburetor mixes fuel and air in the right proportions before sending the mixture to the cylinders. Continental mounts the carburetor on a "spider" manifold at the bottom of the engine, away from the main heat source.

This cold location makes Continental carbureted engines more susceptible to carburetor ice. Carb ice forms when moisture in the air freezes inside the carburetor throat. This ice restricts airflow and can cause the engine to lose power or quit entirely. Continental owners must monitor conditions carefully and use carburetor heat more aggressively.

Lycoming bolts the carburetor directly to the oil sump. Hot oil (typically 180 to 200 degrees) flows through the sump constantly. This heat transfers to the carburetor body and helps prevent ice formation. Lycoming engines still can get carb ice under the right conditions, but it happens less frequently. The natural heating provides some protection without pilot action.

This design choice reflects different engineering philosophies. Continental prioritizes keeping the carburetor in a location that's easy to service and provides good fuel distribution. Lycoming prioritizes reducing carb ice risk through passive heating. Neither approach is wrong, but they require different operating techniques from pilots.

Time Between Overhaul Varies by Model

TBO (time between overhaul) represents the manufacturer's recommended interval for complete engine teardown and rebuild. Think of it like the recommended service interval for a car, except much more expensive and thorough. An engine overhaul costs $25,000 to $45,000 depending on the model and includes replacing or rebuilding nearly every internal part.

Lycoming engines generally offer longer TBOs than Continental models:

Lycoming TBOs:

Continental TBOs:

These numbers represent guidelines, not legal requirements for most private operators. Many well-maintained engines exceed their published TBO by 500 hours or more. Other engines need overhaul early due to problems or abuse. The actual lifespan depends heavily on how the airplane is operated and maintained.

The longer TBOs give Lycoming a real advantage in operating costs. If you fly 100 hours per year, an O-360 Lycoming theoretically lasts 20 years before overhaul. An O-470 Continental lasts 15 years. Over a typical ownership period, this difference can save you thousands of dollars. However, this advantage disappears if you don't fly regularly and face premature camshaft wear.

Common Problems Differ Between Brands

Every engine design has weak points. Understanding these helps aircraft owners budget for maintenance and catch problems early.

Continental Common Issues:

Lycoming Common Issues:

The Continental crankcase cracking problem led to the development of "Phase" crankcases with reinforced areas. Older Continental engines without these improvements face higher risk. Aviation mechanics watch Continental cylinders closely for cracks between the valve seats. These cracks can develop gradually and may not show up on compression tests until they're severe.

Lycoming's camshaft problem overshadows other issues. A spalled cam can destroy an engine in just a few flight hours once the damage starts. The metal particles circulate through the oil system and damage bearings, cylinder walls, and other precision surfaces. Mechanics recommend oil filter inspection at every oil change, looking for any gray metallic material that indicates cam or lifter wear.

Both brands sometimes experience cylinder problems. A cylinder might develop low compression due to worn rings or valves. Individual cylinders cost $1,500 to $3,000 each to replace. Four-cylinder engines need four, and six-cylinder engines need six. Replacing all cylinders during an overhaul represents a major portion of the total cost.

Understanding these common issues helps you work with your mechanic to monitor your specific aircraft engine. Regular oil analysis, borescope inspections, and compression checks catch problems before they become catastrophic. For detailed guidance on maintaining proper documentation and ensuring parts meet aviation standards, resources like How to Verify Traceability and Certification of Used Aircraft Parts provide valuable information for owners and mechanics.

If you fly a popular model like a Cessna 172 with a Lycoming engine, specialized guides such as Cessna 172 Engine Overhaul Time and Cost Explained for Plane Owners break down exactly what to expect when your engine reaches TBO. These resources help you plan financially and understand the process before you face a surprise engine overhaul bill.

The key takeaway is simple: both Continental and Lycoming make excellent engines with different characteristics. Continental offers smoother operation, easier hot starts, and better tolerance for irregular flying. Lycoming provides longer TBOs, proven reliability, and dominance in the training market. Your best choice depends on which airplane you fly, how often you fly it, and what kind of maintenance support you have available.

How to Choose the Right Engine

Most pilots don't actually choose their engine—the airplane manufacturer makes that decision. When Cessna builds a 172, it comes with a Lycoming engine. When Cirrus builds an SR22, it installs a Continental. You buy the plane and get whatever engine is attached to the firewall. But understanding these engines helps you make better decisions about maintenance, overhauls, and even which airplane to buy.

If you're shopping for a plane, the engine type might influence your choice. For example, older Cessna 182s came with the Continental O-470, while newer restart models use the Lycoming IO-540. Both airplanes fly similarly, but they have different operating costs and maintenance needs. The O-470 parts are more available and many mechanics know them well. The IO-540 offers more power and a longer TBO. Your decision might depend on which engine your local mechanic prefers to work on.

Aircraft owners who face an overhaul have more choices. You could overhaul your existing engine at a local shop, send it to the factory, or buy an exchange engine. Some owners even consider switching brands if an STC (supplemental type certificate) allows it. Switching is expensive and complicated, so most stick with the original brand. But if you fly a plane eligible for both engines, you might research which one fits your flying style better.

The frequency of your flying matters enormously for engine longevity. Lycoming engines need regular operation to prevent camshaft corrosion. If you fly every week, a Lycoming will likely reach or exceed its TBO without problems. If you only fly twice a month, you might face premature cam wear. Continental engines handle irregular use slightly better, though they still need regular flights. Neither engine likes sitting unused for weeks.

Your operating environment also matters. Planes based in hot, humid climates face more corrosion issues. Coastal areas with salt air can be particularly tough on engines. Cold climates create different challenges with pre-heating and cold starts. The Lycoming O-320-H2AD (used in some 1970s Cessna 172s) developed a terrible reputation for cam problems in cold northern states. Meanwhile, the same engine performed fine in warmer regions.

Maintenance costs differ between models but not dramatically between brands. A typical engine overhaul for a four-cylinder Lycoming or Continental runs $25,000 to $35,000 at a reputable shop. Six-cylinder engines cost more—$30,000 to $45,000 depending on the model. Factory overhauls or rebuilds can exceed $60,000. These prices assume your crankshaft and crankcase are reusable. A cracked case or bad crankshaft adds thousands more.

When choosing an overhaul shop, look for experience with your specific engine model. Some shops specialize in Lycomings, others in Continentals. Ask about their process, warranty, and turnaround time. Check references from other pilots who used the shop. The cheapest price often isn't the best value. A quality overhaul from a reputable shop might cost $5,000 more but last hundreds of hours longer.

Consider parts availability for your engine model. Both brands have good parts support, but some older or unusual models face longer wait times. New cylinders have been particularly hard to get in recent years. If you fly a common engine like the O-360 or IO-520, parts won't be a problem. If you fly something rare like a GTSIO-520, expect longer lead times and higher costs.

The rpm rating affects the engine's character. Most four-cylinder engines redline around 2,700 rpm. Some Continental engines, like the O-470, redline at 2,400-2,600 rpm and run quieter and smoother. Higher rpm engines typically produce more power from less displacement but may feel busier. This is a design choice by the manufacturer, not something you can change.

Your local mechanic's expertise should influence your thinking. If your trusted A&P has overhauled 50 Lycoming engines but rarely touches Continentals, stick with what they know. An experienced mechanic who understands your engine type will catch problems early and fix them efficiently. Switching to an unfamiliar brand just because you read an article online makes little sense.

Finally, focus on proper operation rather than brand loyalty. Both Continental and Lycoming engines last longest when you fly them regularly, lean the mixture properly, monitor temperatures carefully, and change the oil frequently. An abused Lycoming will fail before its TBO. A well-maintained Continental will exceed its published TBO. The pilot and mechanic matter more than the name on the data plate.

Conclusion

Choosing between a Continental engine and a Lycoming engine rarely comes down to one being clearly superior. Both companies have built hundreds of thousands of reliable engines over nearly a century. They approach the same engineering challenges with different solutions, but both solutions work. Continental engines offer smoother operation, easier hot starts, and excellent high-power performance. Lycoming engines provide longer TBOs, simpler maintenance, and proven reliability in training environments. The "best" engine depends entirely on your airplane, your flying habits, and your maintenance support.

The most important lesson is that regular operation keeps both brands healthy. Engines that fly weekly typically reach or exceed their published TBO. Engines that sit for weeks develop corrosion problems regardless of brand. Proper leaning, temperature management, and oil changes matter far more than the name stamped on the crankcase. If you're buying a plane, focus on finding one with a well-maintained engine and complete logbooks. If you're maintaining a plane, fly it often and address small problems before they become expensive ones.

For more information about aircraft ownership, maintenance, and making smart decisions about your plane, visit Flying 411, your trusted resource for general aviation knowledge.

Frequently Asked Questions

Can I switch from Continental to Lycoming in my plane?

Switching requires an STC (supplemental type certificate) and involves major changes to engine mounts, fuel systems, cowlings, and exhaust. It typically costs $15,000-$40,000 plus the new engine price, making it rarely worthwhile unless required.

Which brand has cheaper parts?

Parts costs are comparable between brands for equivalent models. Common engines like the O-360 and IO-520 have competitive parts pricing. Rare or discontinued models face higher costs and longer lead times regardless of manufacturer.

Do turbocharged engines last as long?

Turbocharged engines typically have shorter TBOs (1,600-1,800 hours vs. 2,000+ for naturally aspirated) due to higher operating temperatures and stresses. They require more careful operation and cost significantly more to overhaul.

How often should I fly to prevent engine corrosion?

Weekly flights of at least 30 minutes with oil temperatures reaching 180-200°F help prevent corrosion. Less frequent flying increases risk, especially for Lycoming engines with top-mounted camshafts.

Are factory overhauls better than field overhauls?

Factory overhauls offer zero-time engines with full warranties but cost 2-3 times more ($60,000-$100,000). Quality field overhauls from reputable shops provide excellent value ($25,000-$35,000) with comparable reliability for most operators.