Since the beginning, camshafts have played essential roles in internal combustion engines. To this day, it is still a crucial component in a car engine. Camshafts consist of a length of rod or shaft, with some cam lobes attached to it. This means a camshaft comprises two components – a shaft and cam lobes.
As the crankshaft engine rotates in sync with the camshaft, the cam lobes depress the valves. The camshaft movement is responsible for the opening and closing of the compression and exhaust strokes in the engine. And it is the camshaft rotating speed that determines how fast the compression and exhaust strokes open and close.
But how many camshafts does a V8 have, and how many camshafts does a v6 have? In today’s article, we’ll explain how many camshafts we have in a car engine. But first, let’s explain how a camshaft works.
Engine Camshafts Explained
A camshaft is a cylindrical rod that runs on the top of the head cylinders with cam lobes attached to the shaft. Each lobe of the shaft is for one valve. These lobes tell the valves when to open by depressing them. In the same vein, it tells the valves when to close.
The valves close as the shaft rotates, and the lobes reach their highest points. This is far from magic. It is technology. The valves have springs that allow them to open and close as the lobes rotate.
Camshaft’s working principles differ between old and modern engines. On old engines, the camshafts help to determine when the air-fuel mixture enters the engine. But on modern engines, their calibration controls the amount of air-fuel mixture that enters the combustion chamber.
However, the camshaft determines when to let the combusted fuel out of the chamber to allow fresh mixture for another combustion cycle.
Technically, several individual components play critical roles in the combustion process. As the fresh air-fuel mixture gets into the combustion chamber, the pistons compress it by pushing it up, making it more combustible. The pistons’ up-and-down movement is synchronized to open and close the valves.
The engine crankshaft and the camshafts are connected via a timing chain or belt. This is not just a connection; they are designed to move in sync.
The synchronization of the camshafts and the crankshaft is called engine timing. The timing allows the cam and crankshaft to control the opening and closing of the valves. And the crankshaft tells the pistons when to move up and down in sync with the cam.
But the questions remains, how many camshafts in an engine? Engines have different numbers of camshafts, depending on their designs. The following paragraphs will discuss how many camshafts in a V8 engine.
How many camshafts does a v8 have?
First, we have SOHC and DOHC engines. SOHC means single overhead cam engine, and DOHC means dual overhead cam engine. All camshafts are mounted on the cylinder heads.
The engine has one camshaft per bank in a SOHC, usually placed between the valve stems. Here, the engine uses a rocker arm to transmit the cam lobes’ up-and-down movement to the valves.
The engine has two camshafts per bank in DOHC, usually placed over the valve stems. One of the camshafts is for the intake valves, while the other is for the exhaust valves. The cam lobes press the valves directly.
From the explanation above, an i4 (4-cylinder) in a SOHC engine have one camshaft, while a V6 and V8 have two camshafts. On the other hand, an i4(4-cylinder) in a DOHC engine has two camshafts, while a V6 and V8 have four camshafts.
So, if you’re asking – how many camshafts does a DOHC V8 have, or how many camshafts does a SOHC V8 have? You now know the answer. A DOHC V8 engine has four camshafts, while a SOHC V8 has two camshafts.
Car manufacturers usually equip a few newer “pushrod” engines and older ones with one camshaft on each bank. In such engines, Pushrods transmit the camshaft up-and-down movement to the rocker arms, which act upon the valves. These engines usually have two to three valves per cylinder, one on the intake and the other on the exhaust.
We repeatedly mentioned banks in this article. You may be wondering what is ‘bank’ in engines. A bank is a cylinder block, also known as a head cylinder. V-type engines usually have two banks. I-type engines such as i4 (four-cylinder) engines have a single bank. Check out this well-detailed article on bank 1 and bank 2 locations to learn more about banks on car engines.
How many camshafts does an engine have?
Several factors, like engine type and cylinder type, determine the number of camshafts in an engine. For this reason, you can’t rightly say the number of camshafts in an engine without knowing the engine and cylinder block type.
However, an engine can have between one to four camshafts. For example, a four-cylinder on the SOHC engine has one camshaft and two camshafts on a DOHC engine. V6 and V8 engines have two camshafts in a SOHC and four camshafts in a DOHC setting.
Do V engines have two camshafts?
Yes, some V engines have two camshafts. As reiterated above, SOHC engines use a single camshaft on four-cylinder engines and two camshafts on V-type engines. However, it is essential to note that DOHC V engines have four camshafts.
Do cars have two camshafts?
Generally, cars have one to four camshafts. However, some four-cylinder engines have two camshafts, and some V-type engines have two camshafts. So, you will see two camshafts on your four-cylinder DOHC engine and two on your V6 or V8 SOHC engine.
What is a four-cam engine?
Four-cam engines are engines with four camshafts. Therefore, you can call any engine with camshafts a four-cam engine. Typically, all DOHC engines on dual cylinders are four-cam engines since they all have four camshafts.
What cars have twin cams?
Twin-cam cars refer to cars with two camshafts per cylinder block. Simply put, twin-cam cars are cars with DOHC engines.
In today’s automotive era, most cars have twin cams. Examples are the Toyota Corolla, Toyota Camry, Toyota Highlander, Toyota Venza, Nissan Sunny, Nissan Pathfinder, Nissan Xterra, Honda Accord, Honda City, Honda Civic, Honda Pilot, and many more.
If you were asking – how many camshafts does a V8 have? You now know the answer. Generally, a V8 engine has two or four camshafts. In SOHC engines, the V8 has two camshafts, and four camshafts in DOHC engines.
This article has explained how camshafts work in car engines and how to determine how many camshafts your engine has. So, it doesn’t matter whether you have a four-cylinder, V6, V8, or V10; you can correctly say how many camshafts it has by determining whether it is a SOHC or DOHC engine.