forged steel crankshaft

Types of forged steel crankshaft

There are four main types of forged steel crankshaft :

• 1. Cross plane crankshaft

  The cross-plane crankshaft is the most popular crankshaft in V8 engines. It makes a smooth power stroke, which makes it popular in heavy-duty and luxury vehicles. The smooth stroke comes from the power pulses being evenly spaced.

• 2. Flat-plane crankshaft

  Flat-plane crankshafts are mainly used in high-performance vehicles. Unlike the cross-plane crankshaft where the journals are at 90 degrees, the flat-plane crankshaft has its journals at 180 degrees. This design makes the vehicle have a high-revving engine.

• 3. Radial crankshaft

  Radial crankshafts are used in aircraft engines and radial engines. The design of radial crankshafts is similar to radial engines. The crankshaft converts the pistons' linear motion into rotational motion so that the engine can generate power.

• 4. Inline four crankshaft

  In an inline-four engine, there are six cylinders. Each of the cylinders houses a piston that moves up and down in sync with the others. The crankshaft converts the pistons' up-and-down motion into rotational motion so the engine can produce power.

Specification & Maintenance of Forged Steel Crankshaft

There are several specifications to consider when buying a forged steel crankshaft:

• Size and Weight

  Consider the dimensions and weight of the crankshaft. The size and weight affect the engine's balance, layout, and performance.

• Stroke Length

  The length of the crankshaft's strokes determines the engine's power delivery and torque characteristics. Longer strokes generate more torque.

• Throw and Journal Diameter

  The throw is the distance from the center of the crank pin to the center of the main bearing journal. It affects the stroke length.

• Material Composition

  A forged steel crankshaft is made from steel alloys. The alloying elements affect the strength and hardness of the crankshaft.

• Firing Order

  The crankshaft's design determines the order in which the engine's cylinders fire. This affects the engine's smoothness and power delivery.

• Balance and Performance

  Consider the balance and performance characteristics of the crankshaft. A well-balanced crankshaft reduces vibration and noise.

• Compatibility

  Ensure that the crankshaft is compatible with other engine components, such as connecting rods, pistons, and the engine block.

Maintaining a forged steel crankshaft is important for its longevity and optimal engine performance. Here are some maintenance tips:

• Engine Oil

  Use the recommended engine oil to lubricate the crankshaft. Maintain the oil level and change the oil at regular intervals to keep it clean.

• Regular Maintenance

  Carry out regular engine maintenance activities. Monitor the engine's condition and address any issues promptly to prevent crankshaft damage.

• Proper Torque Specifications

  When installing components like flywheels and drive pulleys, use the correct torque specifications to avoid uneven loads on the crankshaft.

• Avoid Overloading

  Do not overload the engine, as this can cause excessive stress and strain on the crankshaft, leading to premature wear or failure.

• Crankshaft Inspection

  Inspect and check the crankshaft for damage or wear regularly, especially during major engine repairs. Address any issues immediately.

• Vibration Dampers

  Use vibration dampers or torsional vibration absorbers to reduce the engine's vibrations. This protects the crankshaft from excessive vibrations.

How to choose forged steel crankshafts

There are several factors to consider when choosing the right forged steel crankshaft for an engine, such as understanding the engine's specifications, the crankshaft's stroke, and material considerations.

Read on to explore the various aspects of choosing forged steel crankshafts.

Ultimately, the key to selecting the right crankshaft is understanding the engine's specifications, such as engine size, intended use, and performance goals. This information will guide the selection process and ensure compatibility and performance gains are achieved.

• Consider the Intended Use:

  The purpose for which the vehicle or equipment is designed is important. If the use is for everyday cars, a forged steel crankshaft may not be necessary. However, for high-performance racing vehicles or heavy-duty trucks, a forged steel crankshaft is required to withstand high-stress levels.

• Engine Specifications:

  Buyers should ensure that the forged steel crankshaft matches the engine's specifications, such as engine size, configuration (V6, V8, Inline 4, etc.), and any modifications (e.g., increased displacement, turbocharging) that may affect the crankshaft requirements.

• Consider the Stroke:

  Forged steel crankshafts have different strokes. The stroke measurement affects engine performance. A longer stroke results in a higher torque output and vice versa. Depending on the desired torque and power, buyers should choose a forged steel crankshaft with the appropriate stroke length.

• Consider Material Composition:

  While all forged steel crankshafts are made of steel, there are different grades and compositions. Buyers should consider the specific grades and treatments that offer the best durability and wear resistance for their applications. High-alloy steel with superior mechanical properties is required.

• Balance and Smoothness:

  A balanced forged steel crankshaft is essential for engine smoothness and longevity. An unbalanced crankshaft can cause vibrations, damaging bearings, pistons, and other engine components. Buyers should ensure the crankshaft is precisely balanced to match the engine's specifications and operating conditions.

• Compatibility with Other Components:

  The forged steel crankshaft must be compatible with other engine components, such as connecting rods, pistons, and the flywheel or flexplate. Ensure that sizes, fittings, and balancing requirements work together smoothly. Failure to achieve compatibility can lead to mechanical problems and reduce overall engine performance.

• Brand and Supplier Reputation:

  Buyers should select forged steel crankshafts from reputable brands and reliable suppliers. Researching customer reviews, warranty offers, and after-sales support can help ensure they get quality products and good service.

How to DIY and Replace Forged Steel Crankshaft

Changing a crankshaft can be a troublesome task that requires a lot of patience. Before attempting to DIY, make sure to read through the service manual for the specific vehicle being worked on. Here are the basic steps to replacing a forged steel crankshaft:

• Gather all necessary tools: One will need a complete set of sockets and wrenches, torque wrench, ratchet extensions, a hammer, pry bar, crankshaft pulley removal tool, and possibly some specialty tools depending on the vehicle. Have a quality floor jack and jack stands or wheel ramps for lifting the car. Also, have a good engine support/hoist and stand for working on the engine outside of the vehicle. An organized workspace with proper lighting and good ventilation is helpful.
• Dissassemble other parts of the engine: To access the crankshaft, one must disassemble the engine. Start by draining all fluids from the engine, including oil, coolant, and gasoline. Next, remove the engine from the vehicle. Depending on the car, this may require removing the transmission and/or front-end accessories, exhaust components, and electrical connections. After disconnecting the engine, support it with an engine stand and hoist. Disassemble the engine by removing the cylinder head(s), intake manifold, exhaust manifold, timing components, oil pan, and other accessories. Once the oil pan is removed, the crankshaft will be visible. Before removing it, remove the camshaft and any other components that may obstruct accessing the crankshaft. Then, remove all crankshaft bearings carefully without damaging the housing.
• Remove the old crankshaft: Use a crankshaft pulley removal tool to take out the crankshaft pulley. Then, use a socket and ratchet to remove all bolts securing the front cover or timing cover. This will give access to the crankshaft at the front end. Depending on the vehicle, the next step may involve removing the rear main seal and rear main bearing cap. Consult the service manual for detailed instructions. The rear end of the crankshaft is now accessible. Now, use a crankshaft puller or pry bar to carefully extract the crankshaft from the engine block. This step requires attention to avoid damaging the engine block or other components.
• Install the new crankshaft: Before installing a new crankshaft, lubricate its journals and the new bearings with engine assembly lube to ensure smooth operation from the start. Gently insert the new forged steel crankshaft into the engine block, taking care not to damage the bearings or seals. Reinstall the rear main bearing cap and rear main seal, following the torque specifications in the service manual. Then, reassemble the engine parts in the order they were disassembled. Start with the oil pan, then reinstall the oil, coolant, and fuel. Remember to follow the instructions for disassembly in the service manual. Reinstall the engine into the vehicle, reconnecting all necessary components. Fill the engine with new oil, coolant, and fuel. Carefully start the engine and let it idle for a few minutes. Check for leaks and unusual noises, and address any issues before driving the vehicle.

Q and A

Q1: What is a forged steel crankshaft used for?

A1: The forged steel crankshaft is an important part of the engine. It turns the power from the pistons into usable power for the car.

Q2: Is a forged steel crankshaft worth it?

A2: Yes, it is a good investment, especially for high-performance engines. They might have a higher initial cost, but their durability and reliability can save money in the long run.

Q3: How long does a forged steel crankshaft last?

A3: With proper maintenance, a forged steel crankshaft can last anywhere from 100,000 to 200,000 miles or more. Its lifespan can vary based on factors like load, speed, and maintenance.