If you’ve ever shopped for a used Harley, you’ve probably heard people say, “Just make sure it’s the right year Twin Cam.” And they’re not wrong.
The Harley-Davidson Twin Cam engine has been around for a while—introduced in 1999 and running strong until 2017. But here’s the thing: not every year is created equal. Some are known for rock-solid reliability, while others? Well… they’ve had their fair share of quirks.
I’ve spent a lot of time wrenching on Harleys, riding them, and talking to long-time owners. Whether you’re looking at a Street Glide, Road King, Softail, or Dyna, understanding the good, the bad, and the in-between years of the Twin Cam can save you a lot of trouble—and cash.
Let’s break it all down so you can find the best year Harley Twin Cam engine for your needs.
What Is the Harley Twin Cam Engine?
Before we jump into the best years, let’s cover the basics.
The Twin Cam engine came out in 1999 (2000 for Softails), replacing the Evolution (Evo) motor. Harley needed more power and better cooling, and the Twin Cam delivered. It’s called “Twin Cam” because it uses—you guessed it—two camshafts instead of one.
There were several versions over the years:
- 88 cubic inch (1450cc) from 1999–2006
- 96 cubic inch (1584cc) from 2007–2009
- 103 cubic inch (1690cc) from 2010–2016 (earlier in some Touring models)
- 110 cubic inch (1801cc) for CVO models and some later bikes
Each version brought some improvements, but also some new issues. Some years had cam chain tensioner problems, while others had better oiling systems or stronger bottom ends.
So let’s go through the key changes and pinpoint which year gave us the most dependable, long-lasting version of this iconic V-twin.
Avoid These Early Twin Cam Years (Unless You Like Wrenching)
Let me be straight with you: the early Twin Cams had some rough spots.
The 1999–2006 models came with spring-loaded cam chain tensioners. These little guys are famous for wearing out and causing major engine damage if not caught in time. Harley fixed the issue later, but if you’re looking at a bike from these years, always ask if the tensioners were upgraded.
Especially keep an eye out for:
- 1999–2001 models: These had some of the weakest cam tensioners and oil pumps.
- 2003–2006: Slightly improved but still used spring tensioners unless someone swapped in the hydraulic system.
That said, many riders still love their early Twin Cams —if the cam chain system has been replaced or upgraded. So if you find a clean older bike with documented upgrades (like the S&S gear drive or the Harley hydraulic conversion), it can still be a solid buy.
But if the tensioners are stock? Walk away or budget for a full upgrade.
The Turning Point: 2007–2009 Twin Cam Engines
Around 2007, Harley started making some important changes. That year marked the switch from the 88ci to the 96ci Twin Cam. But the real game-changer? Harley introduced hydraulic cam chain tensioners in their Touring models.
This fix addressed one of the biggest weak points in earlier engines. Unlike the older spring-loaded system, hydraulic tensioners rely on engine oil pressure to keep things in check. That means less wear, more reliability, and fewer worries about your engine eating itself alive.
Still, not everything was perfect.
Here’s what you should know about the 2007–2009 Twin Cam years:
- 2007 was the first year for the hydraulic tensioner system on Touring bikes (Softails and Dynas still had spring-loaded types for a while).
- 2008–2009: More consistent upgrades across different models, but these still had the pressed-together crankshafts—which some riders claim are prone to shifting out of alignment, especially under heavy loads or high RPMs.
- Some engines in this range were prone to excessive heat, thanks to tighter emissions regulations. This could lead to uncomfortable rides in hot weather, especially in stop-and-go traffic.
Despite these quirks, the 2007–2009 bikes are considered more dependable than the early 2000s models—especially if you’re looking at a Touring model. Just keep an eye on that crank runout if you’re planning to install gear-driven cams or build a performance engine.
The 2010 and Later Years: A Big Step Forward
If you’re after the best mix of reliability, performance, and fewer headaches, the 2010 and later Twin Cams start to shine. This is where Harley really refined the platform.
By now, most bikes were coming standard with:
- Hydraulic cam chain tensioners (across all models)
- Improved oiling systems
- Upgraded crankshafts that held up better over time
The 103ci engines became more common in 2012 and were standard in most Touring bikes from then on. These motors offered better torque and smoother power delivery without sacrificing durability.
And let’s not forget the 110ci Twin Cams used in Harley’s CVO (Custom Vehicle Operations) models. While they had more power, they ran hot—and in some cases, even hotter than the 103. Still, many riders love them for the extra grunt, as long as they’re properly tuned and cooled.
A Quick Note on the 2014–2016 Twin Cams
These late-model Twin Cams are some of the most refined in the bunch. If I had to recommend a great year range off the top of my head, this would be it.
Here’s why:
- Factory-installed hydraulic cam tensioners
- The 103ci engine as standard in most models
- Better heat management
- Fewer reported issues with crankshafts
- Vast aftermarket support for tuning, cooling, and longevity
They’re modern enough to include tech like ABS and updated electronics, but still keep that old-school Harley rumble that many riders crave.
The Best Year for the Harley Twin Cam Engine (And Why)
If I had to pick just one year for the Twin Cam engine—based on everything I’ve seen, read, and experienced—it would be 2014.
Let me explain why.
By 2014, Harley had worked out most of the major kinks:
- You’ve got the Twin Cam 103ci engine, which strikes a solid balance between power and longevity.
- Hydraulic cam chain tensioners were standard.
- The Project Rushmore updates kicked in for Touring models—improving cooling, braking, lighting, and overall ride quality.
- Crankshaft stability issues were much less common.
- Electronics were more modern, but still not overly complex.
- And the bikes didn’t run quite as hot as the CVO 110ci monsters.
Many riders call this the “sweet spot” of Twin Cam development. The engine was mature. The bugs were mostly ironed out. And the riding experience was still raw enough to feel like an old-school Harley, but refined enough not to shake your fillings loose.
Of course, it’s not the only good year. If you’re looking for value, some other solid years include:
- 2009 Touring models – first year of the new frame and a big improvement in handling
- 2012–2013 – solid 103ci motors with fewer heat complaints than earlier years
- 2016 – final years before the Milwaukee-Eight launch, making them a bit more affordable now on the used market
But in terms of reliability, performance, and comfort, 2014 hits that perfect middle ground.
Why Not the 2017 Twin Cam 103 or 110?
You might be wondering about 2017. That was the last year Harley used the Twin Cam engine… and yes, it featured some upgrades.
But here’s the thing: 2017 was a transition year.
That year, Harley launched the new Milwaukee-Eight (M8) engine on its Touring models, while Softails still used the Twin Cam 103 and 110. Some folks love the 2017 Twin Cams for their end-of-the-line refinements, but others see them as a little overlooked compared to either the earlier classics or the newer M8s.
In short: If you’re after a Twin Cam, it’s better to go with a model where that engine was the heart and soul of the bike, not the leftover motor in a year when Harley had already moved on for other platforms.
Why Some Riders Still Love 2006
Now, let’s flip the script for a second.
Some experienced wrenchers and longtime Harley owners still swear by 2006 Dynas and Softails—and for good reason.
These were the last year of the Twin Cam 88 with a gear-driven cam option. In stock form, they still used the spring-loaded tensioners, but many owners upgraded to gear drives, eliminating one of the biggest long-term wear concerns. The engines were simple, strong, and easy to maintain if you kept up with the basics.
They also had timeless styling and fewer electronic distractions.
If you’re the kind of rider who enjoys tuning and maintaining your bike yourself—or if you just love that old-school feel—then a 2006 might still be your best bet.
Upgrades That Make a Good Twin Cam Even Better
No matter which year Twin Cam you choose, there are a few upgrades that can make a huge difference in reliability and performance:
- Upgrade the cam chain tensioners if they haven’t already been replaced (especially pre-2007 models)
- Consider gear-driven cams for peace of mind (but only if your crankshaft runout is within spec—usually under .003″)
- Add a high-flow oil pump and cam plate (like the S&S or Fueling kits) for better oiling and cooling
- Use a tuner to reduce heat buildup and improve rideability
- Upgrade your cooling system with oil coolers or fans if you’re riding in hot weather
- Swap in performance lifters and pushrods for smoother power delivery and better longevity
These tweaks can turn even a middle-of-the-road Twin Cam into a rock-solid touring machine or hot rod cruiser—depending on your style.
What to Watch Out for When Buying a Used Twin Cam Harley
So you’re eyeing a Twin Cam bike—awesome choice. But before you hand over the cash, here are a few things to check.
These engines are tough, but like anything mechanical, they have their weak spots—especially if the previous owner cut corners on maintenance.
1. Cam Chain Tensioners (Pre-2007)
We’ve talked about this a lot, and that’s because it matters.
If you’re looking at a 1999–2006 Twin Cam, you must ask whether the spring-loaded tensioners have been replaced. If they haven’t, budget for it. Those shoes can disintegrate over time, sending plastic debris into your oil passages. That’s not the kind of surprise you want 300 miles from home.
The upgrade options:
- Hydraulic tensioners (like on 2007+ models)
- Or better yet, gear-driven cams—if your crankshaft runout allows it
Always check for receipts or documentation.
2. Crankshaft Runout (Especially 2003–2006)
Some years—particularly 2003 to 2006—had issues with crankshafts going out of true.
That’s a problem if you’re thinking of switching to gear-driven cams. Most gear drive kits require crank runout to be 0.003” or less. If it’s more than that, your gears may chew each other up over time.
If you’re serious about building out the motor, get a dial indicator and check it (or have a shop do it).
3. Oil Sumping Issues
Some of the 110ci CVO engines, especially around 2012–2016, have a reputation for oil sumping at higher RPMs. That’s when oil pools in the crankcase instead of returning properly to the tank, leading to power loss and extra wear.
This can be fixed with upgraded oil pumps and cam plates (S&S, Fueling, etc.), but it’s something to ask about if you’re buying one of those bikes.
4. Heat Management
All Twin Cams run hot. But the EPA lean fuel maps make it worse, especially on later 103 and 110 models.
Common fixes include:
- Aftermarket tuners (like Power Vision or ThunderMax)
- Stage 1 intake and exhaust upgrades
- Cylinder head fans or oil coolers
If you’re in a hot climate, this becomes even more important.
Twin Cam Years to Avoid (Or Approach with Caution)
Let’s be clear: almost every Twin Cam year can be great if it’s been taken care of and properly upgraded. But if you’re buying used and want to minimize headaches, here are a few years to think twice about:
❌ 1999–2002
- First-gen tensioner shoes wear out fast
- No hydraulic tensioners
- Lower oil pressure system
- Generally weaker internals
❌ 2003–2006 (If Untouched)
- Crank runout issues
- Still spring-loaded tensioners
- Some bikes were ridden hard and are now showing their age
- But—if upgraded properly, these can be very reliable
❌ 110ci CVO Motors (2012–2016)
- Known for oil sumping, excessive heat, and shorter engine life
- Fun to ride, but they require a lot of cooling and tuning mods
- If you’re a heavy throttle rider, expect more wear and tear
Proceed With Caution:
- 2017 Twin Cam Softails – They’re fine, but it was the final year before the Milwaukee-Eight rolled out. That makes them a bit of an oddball—good engine, but overlooked in the used market.
Quick Year-by-Year Twin Cam Highlights
| Year | Engine(s) | Highlights | Watch Out For |
| 1999–2002 | 88ci | Simpler design, lighter bikes | Cam tensioner failure |
| 2003–2006 | 88ci | Strong aftermarket support | Crank runout, tensioners |
| 2006 (Dyna) | 96ci | First to get 6-speed transmission | Early bugs in new motor |
| 2007 | 96ci | Hydraulic tensioners, better oil system | Still ran hot |
| 2009 | 96ci | Touring frame update | Early heat management issues |
| 2010–2013 | 96ci / 103ci | 103 optional, solid reliability | Watch for mods that weren’t tuned right |
| 2014 | 103ci | Project Rushmore upgrades, ideal sweet spot | Minimal major issues |
| 2016 | 103ci / 110ci | Last full year before M8, good deals now | 110ci heat and sumping |
| 2017 | 103ci / 110ci | Last Twin Cams in Softails | Mixed parts across line, resale quirks |
What’s the Best Year for the Harley Twin Cam Engine?
So, after all that—what’s the best year for the Harley Twin Cam?
If I had to pick just one, 2014 stands out. It’s right in that sweet spot:
- You get the hydraulic cam tensioners
- The 103ci motor has plenty of torque without excessive heat
- The Project Rushmore upgrades (better brakes, improved electrical, and more comfort features)
- Most of the bugs from earlier years were sorted out by then
If you prefer a Dyna, a 2006–2008 model is also a solid bet. The 2006 Dyna was the first to get the 6-speed transmission, and by 2007 it had the upgraded oiling system too.
Want more low-end torque and don’t mind a bit of extra heat? Go for a 2012–2016 Touring model with the 103ci. Just make sure it’s been tuned and maintained.
But honestly? Any Twin Cam from 2007 onward, with proper upgrades and maintenance, can be a great bike that lasts well over 100,000 miles.
Why the Twin Cam Still Matters Today
Even with the Milwaukee-Eight taking over, the Twin Cam still holds a special place in the Harley world.
- It’s easy to work on
- The aftermarket support is massive
- And it just feels like a Harley should—raw, torquey, mechanical
Sure, it runs hotter and vibrates more than an M8. But if you’re the kind of rider who likes doing your own wrenching, tuning your setup, and riding something that feels alive—Twin Cam hits the mark.
There’s also the price factor. Used Twin Cams are now in that golden zone—affordable, well-supported, and still plenty capable for long-haul touring or bar-hopping fun.
What to Ask Before You Buy a Twin Cam
If you’re shopping around, here are a few questions to ask:
- Has the cam tensioner system been upgraded?
- What’s the crankshaft runout (if applicable)?
- Any signs of oil sumping or overheating?
- Has it been tuned for aftermarket intake/exhaust?
- Is there proof of regular oil changes and service?
If the seller can answer those confidently, you’re probably looking at a solid bike.
The Bottom Line
There’s no single “perfect” year, but there is a best fit for every rider.
If you want reliability, go 2007+.
If you love raw feel and DIY tuning, maybe you’ll love a 2001-2003.
If you’re after comfort and touring power, look hard at 2014.
Just remember—maintenance is king. A well-maintained 2005 can be a better bike than a thrashed 2016. The engine’s year matters, but how it was cared for matters even more.
So take your time, ask the right questions, and ride home with something that makes you smile every time you fire it up.
