How To Identify Unknown Camshaft

Without the camshaft, your engine would be worthless. Hence your camshaft is crucial. Every engine needs a timing mechanism that can regulate the opening and closing of the intake and exhaust valves.

A camshaft is a spinning item with protruding cams inside a car that produces reciprocal motion as it rotates and pushes the pistons to generate the engine’s power.

If you are new to engines, you may be unaware of the importance of your camshaft. While you may not need to know much of the time, there is a time when you may be after a new one.

You may identify an unknown camshaft by using your eyes or finding the stamp or engraved numbers on the camshaft. To further identify unknown camshafts, you can alternatively use an analog system.

In our guide, you can get more camshaft identification help to identify unknown camshafts. By the end, you’ll see all the ways you can identify an unknown camshaft and better understand whether it will be used in your car. (Learn How Many Junk Cars Can You Have On Your Property)

unknown camshafts

Are Camshafts Stamped?

As a measure of identification, manufacturers use casting numbers on camshafts. A camshaft’s stamp is not a working component and is only used to identify. The camshaft number identification numbers a manufacturer uses to identify and occasionally track their items.

You can often find the camshaft identifier between the lobes in the middle of the cam. The last four numbers randomly generated 8 or 9-figure values, specifying the Cam Shaft’s precise role.

How to Identify Unknown Camshaft

The best camshaft for your vehicle is what you need, and many vehicle owners find getting a new camshaft to be a bother.

If you don’t have the right one, it won’t fit the engine, and if it would fit, the wrong camshaft could cause severe damage.

Here are three strategies you can use to identify your camshaft selection.

  • Identifying camshafts with your eyes
  • Using stamped numbers
  • Analog system

The essence of knowing how to identify the specs of your camshaft is to avoid errors, unnecessary bills, and frustrations that come along with having the wrong camshaft.

using your eyes

1. Using Your Eyes

There are two types of cams without using a lens, and from the outer look, you can distinguish them. They are the roller camshaft and flat tapped.

Depending on how many lobes each engine block has, you can find other differences, such as DOHC (dual overhead inline) or SOHC (single overhead cam).

Flat Tapped Camshafts

The only thing flat tappet has is the name since the lobes are not flat, so there is no literal meaning, and the slight crown on their faces makes them easy to identify.

They are cheap alternatives compared to roller shafts and are very popular. Inside the lobe is a taper that ensures the hydraulic lifter can spin.

Roller Camshaft

The wheel of a roller camshaft is fastened to the lifter’s body at the bottom. Although roller camshafts don’t use flat in the name, their lobes are flat. For lifter engines, a particular cam is called a roller and has its degree wheel attached to the underside of the lifter’s body.

Compared to other varieties, it lessens friction, increases power efficiency, and increases re-usable features. With a roller camshaft, the valve opens quicker and stays open longer, allowing more airflow and power while decreasing wear. Other camshafts that fall under the umbrella are:

SOHC (Single Overhead Cam)

A SOHC configuration uses two or three valves per cylinder, with one valve allowing air in and the other allowing gases to escape. However, a manufacturer’s engineering skill may also permit a SOHC configuration with 4 valves per cylinder.

There is more optimal open space for air to enter the cylinder and gases to escape when the valves are open, hence airflow is increased compared to a setup with only two valves per cylinder.

Four or six-cylinder can be attached through this configuration to provide average torque to the cams, where higher speeds are not required.

DOHC (Dual Overhead Cam)

The dual overhead cam was introduced to improve the efficiency of an internal combustion engine and deliver more power.

This design separates camshafts and allows the intake valves to be at a larger angle from the exhaust valves to improve airflow. Variable Valve Timing is easy to implement in a DOHC engine.

A DOHC setup allows a 4-valve per cylinder configuration. Usually, it allows higher engine revs for maximum performance and more torque by increasing the valve’s spinning speed.


A pushrod is a metal tube used to communicate directly the value of the valve action of a lifter positioned on the camshaft.

Long-standing in the automotive industry is the overhead camshaft engine type. Because hydraulic lifters use oil to minimize friction, it needs no maintenance and may operate at high speeds making no noise.

The combustion chamber is always above the pushrods’ cam, which remains above the cylinder. (Learn How Much Do Carports Cost)


2. Identify Unknown Camshaft with Stamp Numbers

Manufacturers engrave stamp numbers to keep track of production and distribution. Checking the numbers between the lobes or boxes is the simplest way to get the best results. It has either eight or nine digits.

These figures outline the features or provide information about each product’s specifics. They don’t improve the camshaft’s inherent functionality.

There are ways you can tell the difference:

Model Prefix

As their name suggests, these sets of numbers identify the camshaft model. Again, knowing whether the camshaft works with the alleged vehicle you want to use it for is helpful.

When you see a camshaft number, the first section is the model prefix and shows the model you have.

Grind Number

Another unique way of distinguishing various camshafts is by measuring the lobe separation angle. The ground number is much more famous and well-known than the model number.

For instance, the last two digits of a value like 266H04 are used to show how many lobes are present.

Each number has its interpretation and meaning. For example, the first three-digit value displays the lobes’ average duration time. It shows that at 255 degrees, the valve is open.

In the center is the letter “H.” The definition of “H” is “hydraulic lifters.” The cam is a solid lifter if the letter is an “S,” for example.

Once more, the average length of the lobes is described by the first three values. In that case, 266 denotes the time the valve will remain open at 266 degrees.

Exhaust Number

Sometimes the exhaust number also appears; for example, if you see 266/288, the second reveals the exhausting number. These numbers can be calculated through a dial indicator, a digital measure machine capable of doing such tasks.

3. Using an Analog System

To use this method, you must perform a few activities, such as measuring a few diameters and comparing them to the database. This process is known as an analog system. When a degree wheel or dial indicator is not available, you can use it.

You need to measure a diameter measurement. You must then compare them to the database or catalogs. Consider being given a camshaft to identify. How about you? The bearing’s diameter must first be determined. It is known directly beneath the spider journal, which is another name for the cam.

Measure the toe to heel distance and the diameter of the blushing support journal. Using this data, determine the lift range. You must compare the range value to the catalogs, databases, or online store IDs. The camshaft’s model or kind will then be established.


What makes a cam sound lumpy?

The overlap of the exhaust valve closing and intake valve opening makes the engine inefficient at low speeds. The closer the Lobe Separation Angle, the more overlap; the longer the time, the more overlap.

What makes a camshaft loud?

Cammed vehicles are louder because more fuel goes into the engine, meaning a louder idle and increased noise at any speed according to the cam timing. The added loudness isn’t just from more significant gasoline input; it can come from high-performance cams.

What camshaft is best?

Camshafts The top 3 most dependable camshaft brands for performance cars, according to owners of cars who bought a cam, are COMP Cams, Crower, and Edelbrock.

What does +2 mean in cam LSA?

The LSA and the intake centerline of the cam are machined about one another, which is the quick answer.

The intake centerline is at 110 degrees BTDC because the cam has been machined with a two-degree advance built into it.

How does LSA affect power?

The lobe separation angle on a naturally aspirated engine affects whether the engine reaches peak torque somewhat earlier or later in the rpm range. Peak torque usually occurs at lower rpm with a smaller lobe separation and develops higher in the rpm range with a wider separation.

Where should cam lobes be at TDC?

The intake lobe will pull the lifter up and open the intake valve when the piston is in the TDC intake stroke position. Before the piston reaches TDC, or 0 degrees, the center of the intake lobe will be at a 106-degree angle. (Read Can You Pour Coke On A Car Battery)

What does a camshaft look like?

The camshaft is a shaft with cams attached to it. The cams are accurate oval-shaped protrusions along the shaft. The number of valves and cylinders that make up the engine is closely correlated with the length of the shaft and the number of lobes or cams.

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