Adds Horsepower

Upgrading valve train components is an important factor when it comes to increasing horsepower. When looking at the individual parts, roller lifters and roller rocker arms play a key role in boosting performance. By using these products, the rollers reduce friction between the lifters and the camshaft, and the rocker arms and valves. These products promote efficiency and durability. Camshaft upgrades also provide more horsepower because the lobes have higher cylinder head valve intake and exhaust lifts and longer durations. This allows more fuel and air to be drawn into the engine combustion chamber. After the air and fuel is compressed and ignited, the exhaust valves have to stay open longer so that the gas can leave. This process allows the intake and exhaust valves to work together to produce power.

Stronger Design For Higher RPM Performance

With the improvement in design strength and material, performance valve train components are able to handle the stress and heavy-duty use that is experienced in high-RPM and racing applications.

What Makes Up The Valve Train?

There are a lot of moving pieces when it comes to the valve train:

Camshaft

Rocker Arm

Valve Springs

Pushrods (for Overhead Valve engines)

Lifters

Valves

Retainers And Keepers

Each of the valve train components play an essential role in regulating the air and fuel mixture entering the engine and the exhaust gasses exit. If the airflow is restricted, the efficiency and power of the motor will decrease. Every part performs a key function within the valvetrain to help regulate the intake fuel mixture and exhaust gasses to produce power correctly.

What Are The Three Basic Types Of Valve Trains?

There are three valve train types: the OverHead Valve (OHV), the Single Over Head Cam (SOHC), and the Dual Over Head Cam (DOHC). Each design uniquely controls the opening and closing of the valves and the air/fuel mixture that enters the combustion chamber.

OHV

The OHV uses lifters, pushrods, and rocker arms to open the valves. With the camshaft being located in the block, the timing set generates the cam’s movement through the crankshaft. We see OHV valve trains in mostly V6 to V8 engines because of their weight, complexity, durability, affordability, and compact size.

SOHC

The SOHC valve train features one camshaft located above the cylinder heads. This feature uses a timing chain or belt to drive the camshaft, and eliminates the use of pushrods. Since the valves are operated by less moving parts, the valvetrain style allows you to maintain precise timing at higher RPMs. Although this style does offer easy accessibility, the complexity of the SOHC does add weight and height to the engine for a higher price.

DOHC

The DOHC valve train design uses two camshafts above the cylinder heads. The function of the camshafts is similar to SOHC designs, using a timing chain or belt. Since there is a direct line of operation to the valves, fuel efficiency and power can be optimized. Engine complexity and weight are also increased in the DOHC valve train design. Similar to the SOHC, the height and weight do increase which can affect the overall reliability of the valvetrain.

How Do You Fix A Noisy Valve Train?

Since valve trains are made up of different moving parts, it is key to listen closely to the type of noise the valvetrain is making because it helps narrow down the source. One common source of noise can be linked to excessive clearance. An example would be the clearance between the valve stem tip and the camshaft lobe on an OHV valve train design. When parts start to show wear, they can create clearance between them and result in a clicking noise. To resolve a clearance issue, adjusting the rocker arms or installing replacement shims can correct the ticking noise. The second most common issue comes from the lifters. This part can generate noise from being worn out, dirty, or having a lack of lubrication. By cleaning and lubricating the lifters, the noise should decrease.