Nothing beats the sound, power, and sheer driving pleasure of a muscle car with a V8 engine. The V8 engine is uniquely designed to boost power, speed, and performance. In simple terms, two four-cylinder engines mashed together with a single crankshaft.
But if it has one crankshaft and eight cylinders, how many camshafts does it have, you may ask?
A V8 engine has one, two, or four camshafts, depending on its specific design. The V8 pushrod engine has one camshaft centered between the two banks. The V8 single overhead cam has two camshafts, one for each bank, and the double overhead cam V8 engine has four camshafts, two for each bank.
The V8 engine has revolutionized the motor industry since its first appearance in 1904. With every motoring company trying to get the edge over its competitor, the V8 engine design is constantly being upgraded with new features to enhance its performance.
The first pushrod V8 engine has since been redesigned with a single and a double overhead cam engine, and here are the differences.
Do All V8 Engines Have The Same Amount Of Camshafts?
| Type of V8 Engine | Number of Camshafts |
|---|---|
| V8 Pushrod Single Cam Engine | 1 |
| V8 SOHC (Single Overhead Cam) Engine | 2 |
| V8 DOHC (Double Overhead Cam) Engine | 4 |
The first designed V8 pushrod engine is popular and still competes with its modern SOHC (Single Overhead Cam) and DOHC (Double Overhead Cam) cousins.
Super car and muscle car manufacturers started to change the camshaft design to maximize their cars’ performance and fuel efficiency, adding to the legacy of the V8 engine.
Some V8 engines are powerful low-revving engines, while other V8 engines provide speed. But there are some V8 engines that give the best of both worlds with low torque, power, and speed.
Here are the three different camshaft designs and their functions:
V8 Pushrod Single Cam Engine
- Camshafts: 1
The V8 pushrod camshaft design is the earliest V8 engine. The engine runs with an eight-cylinder like all V8s’ but has one camshaft situated in the middle between the two banks.
The V8 pushrod engine is a V block engine with valves in the cylinder head above the combustion chamber. The camshaft uses pushrods and rocker arms to control the valves on top of the engine.
V8 pushrod engines are known for low-end torque because they only have two valves per cylinder; one for the fuel intake and one for the exhaust gas.
Because this V8 engine only has one camshaft in the center, it needs pushrods to open these valves on both banks. More than two valves per cylinder do not work on a pushrod V8 engine.
The advantage of a single-center camshaft V8 engine is that it only has two valves per cylinder. Because it only has two valves, it provides better airflow giving the engine a lot of power on low revs.
V8 SOHC (Single Overhead Cam) Engine
- Camshafts: 2
The V8 engine has four cylinders per bank running on a single crankshaft, producing eight cylinders. Each bank needs a camshaft to open the valves.
A SOHC (Single Overhead Cam) has a single camshaft controlling four cylinders meaning a V8 has two camshafts, one on each bank. An overhead cam means the camshaft sits right on top of the valves to open and close them.
A SOHC can control two or three valves per cylinder, although modern technology has brought new designs that run four valves on one camshaft. A SOHC V8 has a single camshaft on every bank to improve fuel efficiency without taking too much of the low torque power.
Because an overhead cam can control more than two valves, more fuel can go into the cylinder simultaneously to boost performance.
More valves also mean exhaust gasses are pushed out quickly to get a faster new air and fuel cycle. In conclusion, a SOHC V8 engine has two camshafts.
V8 DOHC (Double Overhead Cam) Engine
- Camshafts: 4
The V8 DOHC (Double Overhead Cam) engine has four camshafts and gives better volume metric efficiency for better performance.
Like the SOHC (Single Overhead Cam), the camshafts are on top of the valves, but with the DOHC V8, there are two independent camshafts on each bank.
The SOHC V8 uses cam-lifters to control the valves, and the DOHC V8 has two camshafts: one for the intake of fuel and a separate one for the exhaust gas. This design gives the V8 engine better top-end power and better fuel efficiency.
Because the DOHC does not have cam-lifters, each camshaft has a cam follower on each valve to directly control each valve.
The DOHC V8 is a big improvement on the Pushrod V8, and it is better than the SOHC, but with more weight and moving parts, it is also a lot more expensive. The four camshafts on the DOHC V8 make the motor bigger, but in this instance, bigger is better.
Which Is Best, The OHV, SOHC, Or DOHC V8 Engine?
The biggest downside of an OHV (Overhead Valve) V8 pushrod engine is that it is challenging to precisely manage the valve timing at high rpm due to the number of valve train components. An OHV design is, therefore, better suited for big engines that provide greater torque at lower RPMs.
A SOHC (Single Overhead Cam) engine permits two or three valves per cylinder, with one valve allowing air in and the other allowing exhaust gas to exit.
Due to the larger space for air to enter when the valves are open, it would provide more torque at mid and low revs. With a SOHC configuration, the camshaft is typically positioned in the center of the head and blocks the spark.
The DOHC V8 has individual camshafts, and the intake valves are farther away from the exhaust valves, allowing for more direct airflow into the engine. Additionally, a DOHC V8 engine makes adopting variable valve timing technology simpler.
Two independent camshafts with 4 valves per cylinder enable the DOHC V8 to get better airflow at high engine speeds. Additionally, DOHC V8 engines enable the spark plug to be positioned directly in the middle of the compression chamber, which encourages effective combustion.
If you are a V8 engine fan, it does not matter which one is under the hood of your car but comparing a V8 OHV, SOHC, and a DOHC, the DOHC (Double Overhead Cam) champions the other two.
Conclusion
A V8 engine can have one, two, or four camshafts. An OHV (Overhead Valve) is a single camshaft for both banks, also known as a pushrod V8. Then the V8 has a SOHC (Single Overhead Cam) with two camshafts, one on each bank.
The DOHC (Double Overhead Cam) has four camshafts, two for each bank. Single-camshaft V8s are low-torque engines, and two and for camshaft V8s are for power and speed.
