The 6.4 HEMI engine delivers up to 485hp and 470 lb-ft from the factory. It might be plenty of power for most, but some of us are always looking for more. The good news is that the large 6.4L V8 leaves a lot of potential for more power. Without question, a 392 HEMI cam upgrade is one of the best mods to push the engine to the next level. In this article, we discuss 6.4 HEMI camshaft upgrades including power gains, benefits, cost, lifters, and more.
About 6.4 HEMI Camshaft Upgrades
6.4 HEMI cam mods aren’t as simple as standard bolt-on mods like a tune, headers, intake, etc. Duration, valve lift, and lobe separation angle are important factors in aftermarket camshafts. Most cam upgrades aren’t designed for MDS so that’s another major topic. 392 HEMI cams are also expensive and challenging to install.
The point is – this isn’t the kind of modification you want to dive into overnight without proper knowledge and info. In the next few sections, we’ll lay out all the basics you should know before buying a 6.4 HEMI camshaft kit. Then, we will move onto the benefits of cams and discuss a few of the best Mopar cam upgrades.
MDS Delete for 6.4L Cams
All cars equipped with the 6.4 HEMI and an automatic transmission use Chrysler’s Multi-Displacement System – or MDS for short. The exceptions are manual cars and Ram 2500 and 3500 trucks. These models do not use MDS. If you do have MDS then you’ll need to delete the system for most cam upgrades. This is done with the following:
- Tuning to disable MDS
- Non-MDS lifters
- Solenoid delete plugs
It’s nothing major since you’ll need a tune with the camshafts anyway. Some cam kits include non-MDS lifters and most will at least give an add-on option. MDS solenoid delete plugs aren’t absolutely required, but it’s a good idea to do things right and throw in some plugs.
6.4 HEMI Cam Specs
When looking at 6.4 HEMI camshaft upgrades you’ll likely be met with a barrage of numbers. For example, specs on the Comp Stage 2 package are 222/230 .599/.604 115. Those less familiar with cams probably feel overwhelmed. I know I did when I was first learning about camshafts. Here’s what each number represents:
- 222/230 = valve duration @ 0.050″ lift
- .599/.604 = valve lift
- 115 = lobe separation angle (LSA)
Specs for the non-MDS 6.4 HEMI camshaft are 215/221 .574/.541 121. It’s already quite a bit more aggressive than the 186/208 .499/.493 115 cam in the 5.7L HEMI. Anyway, let’s jump in and take a further look at the meaning of these cam specs.
392 HEMI Cam Valve Duration
The first set of numbers (222/230) indicate valve duration for the intake and exhaust valves, respectively. Duration at 0.050″ is the important number, and the industry standard for aftermarket cam specs. You might also see advertised duration which is usually ~50 higher.
Valve duration is the amount of time – measured in degrees of crankshaft rotation – that the intake and exhaust valves are open. Keeping the valves open longer means you can move air in and out more effectively. It’s especially important on the top-end where valves are moving quickly. In general, a longer (higher) duration helps top-end power while shorter (lower) duration is best for low-end torque.
6.4L V8 Camshaft Valve Lift
Valve lift – .599/.604 in our Comp Cams example – is the distance in inches that the valves open from their seats. Again, the numbers represent the intake and exhaust valves, respectively. The further the 392 HEMI valves open the more air can flow in and out of the cylinders.
Higher lift actually delivers better horsepower and torque throughout the whole RPM range. Therefore, it’s not a tradeoff for top-end or low-end as is the case with valve duration from above. Though, valve lift is limited by a few different factors.
6.4 HEMI high lift camshafts require valve spring upgrades, so that adds to the cost of increasing lift. However, we highly recommend upgrading the valve springs regardless of lift. Head work may also be required for high lift cams, and there are a few other concerns/issues with running too much lift. Valve lift over 0.650″ on the HEMI engines is usually on seen in the racing world.
Valve lift in the .580″ to .600″ ballpark is common for most modest 6.4 HEMI camshaft mods. Aggressive options like the stage 3 Comp Cams deliver .632/.619 lift. Those specs require the use of a cam phaser limiter or lock kit. More on that in a few sections.
6.4 HEMI Cam Lobe Separation Angle (LSA)
The final 115 number in our example is the Lobe Separation Angle (LSA). LSA in the number of degrees between the peak lift of intake and exhaust lobes. 6.4 HEMI LSA plays an important role in more than just the powerband. It can also affect idle quality, vacuum, and cam rpm range.
Some camshafts, like the Texas Speed options, show LSA as 113+3. The +3 means cam timing is advanced 3 degrees, and this is where things get a lot more complex. Bringing cam timing advance into things means you also have to consider the intake centerline (ICL). This is more technical than intended for this article, so we’ll avoid going down that road.
Ultimately, the benefits of higher LSA are a wider powerband and better top-end horsepower. The 121 LSA on the stock cam is higher and more aggressive than most aftermarket options. Most cam upgrades use an LSA around 112-118 and that’s a good ballpark to stick with. Don’t stray too far away from that range unless you’re working with a professional or really know what you’re doing.
Considerations Before Camming the 392 HEMI
Alright – it’s almost time to jump into the more exciting information in this article. However, there are still a few considerations to discuss before moving onto 6.4 HEMI camshaft benefits and the best cam upgrade kits.
All the details highlight the fact this isn’t a mod you want to suddenly jump onto overnight. Ensure you do plenty of research before buying cams, or work with a reputable shop that can help you pick the right 392 HEMI cams. Anyway, let’s knock out these last couple topics then move onto benefits and 6.4 cam upgrade kits.
Chrysler 6.4 HEMI Valve Spring Upgrades
Valve spring upgrades came up quickly when discussing 6.4L V8 HEMI valve lift above. Most aftermarket cams should take advantage of higher lift. Remember, more lift delivers benefits throughout the entire rev range and there isn’t a major trade-off. As such, valve lift is where cam upgrades are going to deliver good power gains.
However, higher lift puts more stress on the OEM valve springs. If you’re looking at cams over .580″ lift then you should definitely opt for valve spring upgrades. Spring kits should advertise the maximum recommended lift. Additionally, most cam kits will include proper valve spring upgrades for the cam profile.
6.4L HEMI Cam Phaser Limiter or Lock Kits
Chrysler HEMI engines are interference engines. This means there is overlap in the area the pistons and valves travel. As such, increasing valve lift and duration poses some risks. Pistons and valves could contact each other and cause serious damage with too much lift and duration.
Since the 6.4 HEMI uses Variable Valve Timing (VVT) there are cam phasers that adjust cam position on the fly. These phasers allow for a large range of movement so bigger, aggressive cams can cause pistons and valves to collide.
This is where 392 HEMI cam phaser limiters and lock kits come into play. Comp Cams phaser limiter kit will limit the cam phasing to 7 cam degrees. This ensures the pistons and valves have the necessary clearance. Another option is a lock kit which totally locks the cam phasers from moving at all. Some cam phaser movement does help maximize power and torque, so we recommend using a limiter kit over a locking kit.
Most modest stage 1 and 2 cams will not require a limiter or lock kit. However, they’re required when moving to something like a Comp Cams stage 3 kit with .632″ of intake lift. Keep this in mind if you’re looking for aggressive 6.4 HEMI camshaft kits.
Complete Cam Upgrade Kits
Finally, the last topic before moving onto 392 HEMI cam benefits and upgrade recommendations. You might want to consider replacing other parts while you’re in there doing the cams. Many stores offer multiple cam options and/or kits. One option is simply purchasing the camshaft by itself. You’ll then need an MDS delete kit and non-MDS lifters for mild cams. More aggressive cams you’d also want to source a limiter/lock kit and valve springs.
We don’t recommend that route, though. A 6.4 HEMI camshaft upgrade is a serious mod that’s expensive and complex to install. It’s best to do things right the first time around and opt for a complete kit. This is especially true on older HEMI’s. The Comp Cams Master Cam Kit includes the camshaft, lifters, limiter, pushrods, valve springs, seats, seals, and plenty more. They’re all great things to replace/upgrade while you’re in the area.
It’s also smart to replace things like the head gaskets, valve cover gaskets, and other inexpensive parts while in the area. This shouldn’t add much – if any – additional labor and helps ensure a reliable setup for the future.
All this work and replacement parts isn’t totally necessary for a cam upgrade. However, again, this is an expensive and time consuming upgrade. If you’re having the work done at a shop it can easily total $2,500-4,000+. It’s not a small job where you want to cut corners. Do it right the first time and save yourself from potential expenses and headaches down the road.
6.4 HEMI Camshaft Upgrade Benefits
Benefits of upgrading the 6.4L HEMI camshaft include:
- 30-60+ horsepower
- 10-30+ torque
- Better powerband
- Amazing sounds
As you likely understand or guessed, all the benefits of Mopar cam upgrades are performance-oriented. Big, aggressive cams designed for high-rpm can show gains of 60+ horsepower. Too big of a cam can hurt low-end performance, though.
On the other hand, the right 6.4 HEMI cam can deliver great peak gains while also improving performance through the entire power curve. It’s possible to see peak gains around 30-50whp and even gain power in the low-end and mid-range too. These moderate cams are generally the best pick for street use and daily driving.
We also believe 392 HEMI camshaft upgrades sound incredible. Your neighbors might not love the sound of a cammed HEMI at 6am. However, you’ll surely get plenty of thumbs up and signs of appreciation from HEMI owners and car enthusiasts alike.
Best 6.4 HEMI Camshaft Kits
If you made it this far hopefully you have a solid understanding of 392 HEMI cam upgrades. That was a good chunk of info to cover and the article could be much longer if we dove deeper into technical details. Anyway, a lot goes into camshaft mods and it might not be the right upgrade for everyone.
However, if you’re set on a 6.4 HEMI camshaft upgrade then you’re in luck. We’ve done all the research to compile a quick list including a few of the best cam kits and upgrades. Please note – this isn’t an exhaustive list and plenty of good cams are out there. Instead, we’re focusing on a few common 6.4L V8 cams that are highly proven, deliver great performance, and come from reputable, quality brands.
*The specific cams we reference are designed for naturally aspirated (NA) HEMI’s. Supercharged or turbo applications are best suited to cam profiles designed with boost in mind. Most of the brands we mention also have cams for SC and turbo engines, so keep that in mind if you’re planning to add boost in the future.
1) 6.4 HEMI Comp Cams Stage 2 Master Kit
Power Gains: 30-50+whp
We referenced Comp Cams in this article several times for a reason. They’re the real deal when it comes to cam upgrades for many different cars and engines. Comp Cams puts a lot of R&D and testing into their cam kits and the results and success speak for themselves.
Their 6.4 HEMI stage 2 master camshaft kit includes all you can possibly need from a cam kit. The kit includes the cam upgrade, lifters, limiter kit, pushrods, valve springs, spring seats, seals, and everything in between. If you’re looking to do things right then this cam kit is a great pick.
The stage 2 camshaft specs are 222/230 .599/.604 115LSA. Peak power gains will likely come in around 40-50whp with the stage 2 cam. This camshaft delivers great power throughout the entire rev range, so you’ll likely see small gains down low too.
Comp Cams has some more aggressive stage 3 options for the 6.4L HEMI. These options will deliver great mid-range and top-end, but low-end torque will likely drop off a small amount. Ultimately, the more aggressive cams are great for race builds or weekend drivers. They’re probably a little overkill for frequent street use or daily driving, though.
2) Texas Speed 6.4 HEMI Camshaft Package
Power Gains: 20-60+whp
Next up is the Texas Speed & Performance (TSP) camshaft package. TSP is another highly reputable and well respected brand that builds some great 6.4 HEMI cam kits. This Texas Speed kit isn’t as complete as the Comp Cams kit above, but it’s still a great option with some good upgrades included such as pushrods and valve springs.
The TSP package does not include non-MDS lifters or any MDS delete parts. As such, if you have an MDS 6.4L V8 then you should also pick up their MDS delete kit. This includes the option for non-MDS lifters along with all the gaskets and bolts that should be replaced along the way.
Anyway, the cam package includes your choice of a stage 1 to stage 4 camshaft. All the TSP cams use the same .582/.582 lift with each higher stage delivering more LSA and duration. The stage 3 specs are 223/232 .582/.582 113+3, so this is very similar to the stage 2 Comp Cams offering. It’s likely the best option for most street HEMI’s while the stage 4 is best for racing use.
3) 6.4L V8 MMX Max Effort Performance Cam Kit
Power Gains: 30-50+whp
Buy Here: MMX 6.4 HEMI Performance Camshaft Kit
The Modern Muscle Xtreme 6.4 Max Effort Performance Cam is another great option. If you’ve owned a HEMI for more than 3 days you’re probably familiar with MMX. These guys have been around for a while and build some great Mopar parts.
It might be the most expensive kit on this list, but it includes some awesome parts. With the MMX cam package you’ll receive the camshaft, Hellcat lifters, pushrods, PSI valve springs, retainers, locators, and the phaser limiter. Duration is 22x/23x and LSA is 112.5. Unfortunately, we couldn’t find valve lift specs anywhere.
Nonetheless, the MMX 6.4 HEMI camshaft should deliver performance similar to the TSP stage 3 and Comp Cams stage 2. It’s a quality kit that also delivers some great sound (this is the cam in the above video).
6.4 HEMI Cam Upgrade Summary
The 6.4 HEMI delivers good power and performance from the factory. However, it has plenty of aftermarket potential and a cam upgrade is one of the best mods to unlock crazy power. A 392 HEMI cam is a complex and major upgrade so it’s important to understand what you’re getting into. A few considerations before choosing a HEMI cam include:
- MDS & delete kits
- Cam profile/specs
- Phaser limiter kits
- Other upgrades/replacement parts
Cams can be a little overwhelming at first, but a little research and reading goes a long way. Those who made it this far in the article hopefully have a solid foundation to get started on a camshaft upgrade.
TSP and Comp Cams are the two most popular 6.4 HEMI camshaft upgrades. They both build awesome, quality kits with multiple cam options for different goals and needs. We think the TSP stage 3 and Comp stage 2 are the best options for most street-driven HEMI’s. These cams deliver great peak gains of 40-50+whp and possibly even improve low-end torque.