Can a 5.7 Hemi handle a cam?
Yes. A 5.7 Hemi can be cammed, but you must choose a compatible cam profile and plan for supporting upgrades and a tune to maintain reliability and drivability.
Understanding what a cam does
A camshaft controls when valves open and close, how long they stay open (duration), and how far they lift the valves (lift). Swapping to a different cam changes airflow through the intake and exhaust, which alters power, torque, idle quality, and fuel economy. Modern engines like the 5.7 Hemi rely on electronic control, variable valve timing, and hydraulic lifters, so a cam change typically goes hand in hand with a reprogram or reflash and may require additional parts to keep the engine running smoothly at all RPM ranges.
Can a 5.7 Hemi physically accommodate a cam change?
Yes, in most cases a 5.7 Hemi can accept a cam upgrade, but there are practical constraints. The engine’s DOHC design with variable valve timing and cylinder deactivation (on some models) means the cam profile must be compatible with the existing piston-to-valve clearance, valve springs, lifters, and the engine’s electronic control strategy. Aggressive cams can push these limits, so many builders recommend matching the cam to the headwork, ensuring proper spring follow, and planning a tune to recalibrate fuel, timing, and MDS behavior if equipped.
Cam option categories
Cam profiles are commonly grouped by how they affect daily drivability and peak power. The following categories are typical for the 5.7 Hemi:
- Mild street cam — improves throttle response and midrange without sacrificing idle quality or daily usability.
- Mid-range performance cam — noticeable gains across a broad RPM range, often requiring a tune and some supporting mods.
- Aggressive/track cam — maximum power at higher RPMs with potential idle roughness and reduced low-end torque; usually demands significant supporting work (tuning, exhaust, intake, springs, and possibly fuel-system upgrades).
Choosing the right cam depends on your goals, whether you want a more responsive daily driver or a stronger high RPM machine, and your budget for supporting parts and labor.
Supporting upgrades and tuning
To realize a cam swap on a 5.7 Hemi, most builds require more than just swapping the cam. The following areas are commonly addressed to ensure reliable operation and to maximize power gains:
- ECU calibration or reflash — to accommodate the new cam profile, timing behavior, and any MDS considerations.
- Valve train compatibility — higher lift or different duration often necessitates stronger valve springs and possibly upgraded retainers; lifters and followers should be checked for compatibility with the new cam.
- Break-in procedures — proper lubrication and a controlled break-in sequence to seat lobes safely.
- Intake and exhaust work — a cam swap is frequently paired with improved intake flow and a more free-flowing exhaust to realize the gains.
- Fuel system considerations — aggressive cams can demand more fuel; injector sizing and fuel pump capability may be evaluated, especially for high-RPM or large-lift cams.
- Drivetrain and cooling considerations — depending on the cam and power level, ensuring adequate cooling and drivetrain support (transmission, torque converter, etc.) helps reliability.
In short, most cam swaps for the 5.7 Hemi require a tune and at least some level of supporting hardware or adjustments to realize a reliable and durable result.
Practical outcomes and considerations
Expect noticeable differences in throttle response and mid-range power with a mild cam, plus smoother power delivery with day-to-day driving. More aggressive cams can broaden the power band toward higher RPMs but may compromise idle quality and low-end torque. Fuel economy can vary and warranty implications should be considered, especially on newer, still-supported vehicles. Always verify compatibility with your exact model year, MDS configuration, and any emission-related controls.
Bottom line
The 5.7 Hemi is capable of handling a cam, but success hinges on selecting a cam that suits your goals and on performing the necessary supporting work—tuning, valve-train upgrades, and possible fuel/system adjustments. A measured, vendor-approved approach typically yields the best balance of power, drivability, and reliability.
Summary
Can a 5.7 Hemi handle a cam? Yes, with careful planning. The key is matching the cam profile to your goals and ensuring the engine’s timing, valve train, fueling, and ECU are properly addressed. Mild cams offer easy, street-friendly gains with minimal headaches; more aggressive cams deliver bigger power gains but require more extensive upgrades and tuning. Always consult with reputable cam suppliers and tuners to tailor a plan for your specific build and goals.
How much horsepower can a Cammed 5.7 Hemi make?
A 5.7L Hemi camshaft upgrade can add 40-70+ horsepower, depending on the specific cam and other supporting modifications like headers, a tune, and exhaust system. A conservative street cam might add around 40-50 hp, while more aggressive or "stage 4" cams can provide 70 hp or even up to 85+ hp and more in the engine's power band.
Factors that influence power gains
- Cam profile: Aggressive cams with higher lift and longer duration will produce more peak horsepower but may sacrifice low-end torque and idle quality.
- Supporting modifications: For best results, a cam upgrade is often paired with other parts:
- Headers: Long-tube headers can add significant power, especially with a cam.
- Tune: A custom tune is crucial to optimize the new cam's performance and is necessary for a noticeable gain.
- Exhaust: Upgrading the cat-back exhaust system can help increase power.
- Fuel system: At higher power levels, you may need to upgrade fuel injectors and a fuel pump.
- Engine requirements: The Hemi's high compression and free-flowing heads make it very responsive to cam changes, and it may require disabling the Multi-Displacement System (MDS).
Examples of performance gains
- Moderate street cam: An aggressive but streetable cam may add approximately 65-67 horsepower.
- High-performance cam: A "Stage 4" cam, with supporting mods like a torque converter, can add 85+ horsepower, significantly expanding the engine's usable RPM range.
- Combined modifications: One test saw a 5.7L Hemi gain about 80 horsepower from just the cam, with an additional 40 horsepower from long-tube headers and a 93-octane tune.
How much HP can a stock 5.7 Hemi crank handle?
The OE cast crankshaft can handle about 650 hp and 7,000 rpm (for a limited time).
What do I need to cam my 5.7 Hemi?
To cam a 5.7 Hemi, you will need a new camshaft, lifters, lifter guides, pushrods, and a new timing set (chain, gears, and tensioner), along with gaskets and seals for the heads, intake, water pump, and timing cover. You will also need specialized tools like a harmonic balancer puller, a dial indicator, a pushrod length checker, and a torque wrench to perform the installation correctly.
Parts needed
- Camshaft: Choose a cam that suits your performance goals.
- Lifters: New lifters are necessary when installing a new camshaft.
- Lifter guides: These keep the lifters aligned.
- Pushrods: These connect the lifters to the rocker arms.
- Timing set: This includes a new timing chain, gears, and tensioner.
- Gaskets and seals: You will need new gaskets and seals for the cylinder heads, intake manifold, water pump, timing cover, and oil pan.
- Head bolts: It is best to replace the head bolts when removing the heads.
- Thermostat and gaskets: It's a good idea to replace these while you have the cooling system apart.
- Harmonic balancer bolt: A new bolt is needed for reinstallation.
Tools needed
- Harmonic balancer puller: To remove the crankshaft harmonic balancer.
- Torque wrench: To ensure all fasteners are tightened to the manufacturer's specifications.
- Pushrod length checker: To verify you have the correct pushrod length.
- Dial indicator: For accurately measuring valve lift and cam timing.
- Cam degree kit: To precisely time the new camshaft.
- Crankshaft socket: Some kits attach to a degree wheel, making adjustments easier.
- Standard engine assembly tools: Including sockets, wrenches, screwdrivers, etc.
How hard is it to put a cam in a 5.7 hemi?
Replacing the cam in a Gen 3 Hemi is a little more involved than some other engines. While it is possible to swap a cam with the engine in the vehicle, replacement of the timing chain and guides requires removal of the oil pan. This can be difficult or nearly impossible in a car.
