How Many Spark Plugs Does a Hemi Have?

The spark plug is a device that delivers electric current from the ignition system to the combustion chamber.

The main function of this is to ignite the compressed fuel or air inside the chamber.

The heat from the combustion chamber to the cooling system can be alleviated by the use of spark plugs.

It’s a necessity for your 5.7 engine to have this device. The extra power provided by spark plugs enhances the performance of an engine.

If you have faulty plugs, you’ll compromise the potential of your engine.

You might be wondering how many sparks plugs you need for a single engine and what spark plugs fit it.

It’s over, worry no more. You can get the list of the spark plugs model you need from this article.

Spark Plugs

What Is A 5.7 Hemi Engine?

The pushrod for the 5.7 Hemi engine is similar to those used in the earlier Magnum series engines.

It’s made by Chrysler, one of the biggest automobile companies in the US. According to a Mechanic Insider article, it is a third-generation Chrysler V8 engine.

There is an aluminum cylinder head material and a cast-iron cylinder block in the 5.7 Hemi engine. A smooth and improved experience can be achieved with 16 spark plugs.

Compared to older models, this version has a flatter design and larger shelves on both sides to reduce emissions.

Increasing engine efficiency is one of the things that this feature helps in. 16 spark plugs contribute to these two benefits.

A cylinder deactivation system is incorporated with the 5.7 Hemi engine. For a more eco-friendly approach, it works to save fuel and emissions.

The 5.7 Hemi engine has undergone several changes since it was released. Variable Valve Timing or VVT is a change in the 5.7 Hemi engine.

The purpose of this customization is to improve volumetric efficiency and breathing under a wide variety of conditions.

Buying Guide for Spark Plugs

It’s important to make a list of considerations before purchasing spark plugs for your engine.

It’s important to make sure that what you choose is compatible with the 5.7 Hemi version that you have.

You can use the factors provided below to choose the perfect spark plugs for your engine.

Engine Compatibility

The manufacturer’s recommendation is the best option to follow when choosing spark plugs for your 5.7 engine. Specific spark plugs are required for this specific engine.

It is more important to follow your car’s preference than it is to follow yours.

The spark plugs and the engine must be compatible. If you don’t pay attention, it might affect the performance of your engine.

Ease Of Replacement

It is a good idea to get the original parts if you are not an expert and you are replacing spark plugs for the first time.

You will no longer have to go through complex installation and mechanisms with this move.

If you are already used to changing spark plugs for your 5.7 Hemi, make sure that the parts fit. Don’t forget to match the model of your engine with the plug replacements.

Gap Style 

A wide range of engine types can be fit by most spark plugs. Some things work on their own. With the proper gap excess, it would be best to be cautious.

The engine’s stability is determined by the gap between the electrodes.

It helps in the engine’s running by ensuring that proper voltage occurs for fuel generation. The optimum gap for the engine is 0.43 inches.


A thread size that suits the engine’s needs is one of the key factors in choosing a thread.

Carbon deposits can build up and cause holes in the spark plug if the thread reach is too short.

If the size doesn’t match, the spark won’t properly ignite. You can choose from 10mm, 12mm, 14mm, 16mm, and 18mm thread sizes.

Spark Plug Types

To make a good decision about what spark plugs to use, you must know their types and characteristics. The three famous spark plugs are copper, Platinum, and iridium.

Copper Spark Plug

This is the type of plug that is most famous. Plugs need to possess high-temperature stability because of copper’s high conductivity.

For a long time, copper doesn’t have the strength or resilience to last. For earlier engine versions, it is used.

Iridium Spark Plug

There are three materials for a spark plug, and Iridium is the most durable of them all. Features and qualities make it great for long-term use and benefits.

The iridium spark plug requires less amplification than other spark plug types.

Platinum Spark Plug 

The core material for a spark plug is the metal Platinum, and it is proven to be strong. It’s possible to hold high temperature and heat stress resistance with Platinum spark plugs.

Platinum spark plug helps to prevent unwanted deposits or build-up occurrences, and there is double Platinum in the market which gives a longer life span.


The latest or newer versions of the 5.7-Hemi engine need 16 spark plugs for maximum potential.


What Does HEMI Stand For?

There is a shortened version of the word “hemispherical” that relates to the engines that have hemispherically shaped combustion chambers.

Motor Trend said that the engine’s performance is influenced by the Hemi chamber’s characteristics and shape.

A typical overhead valve design can produce a rapid rise in pressure in the combustion chamber.

Why Does The 5.7 Hemi Have 16 Spark Plugs?

Two valves per cylinder are required for the 5.7 Hemi engine. Chrysler’s older engines have emission problems, and the first two spark plugs can be used to solve them.

The other two plugs start a fire to make sure there is complete combustion.

In simpler terms, each cylinder of the 5.7 Hemi engine has two spark plugs in it to make sure that the car gets complete combustion.

Fuel-saving and emission reduction can be accomplished with the help of spark plugs. The main goal of having more spark plugs in a 5.7 Hemi is to aid the planet’s problem.

The spark plugs make sure that the engine will produce cleaner emissions.

How Often Do I Need To Change Spark Plugs In A 5.7 HEMI?

Changing spark plugs should be done every 10 years or when your car has traveled more than 160,000 km.

It is always a good idea to check the spark plugs from time to time to make sure they are in good shape.

There are different lifespans for spark plugs depending on the material and the manufacturer. The state of your spare spark plugs should be of interest to you.

Spark Plugs


The quality of the spark plugs is the most important factor in the function of your 5.7 Hemi engine.

When faulty plugs start to show, it is important to choose the best and most fitting plugs. It’s not a good idea to reconsider getting the most compatible engine you can get.

The performance of your engine can be improved by using spark plugs. It will be worth the penny and some research.

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