From the factory, a motor is designed to withstand average driving conditions. The internal components are matched in terms of strength and weight and balance is achieved. But when horsepower is added through modification, by insatiable tuners like ourselves, that balance is disturbed.
Making internal parts lighter and stronger is a critical part of building a performance engine. This is commonly done for pistons and connecting rods, but the crankshaft is often overlooked. The result? Engine builds that do not perform to their true potential and will not last over time.
Why Your Crankshaft is Holding You Back
The crankshaft is the part of your rotating assembly responsible for turning the vertical motion of the pistons into rotational force so that it can be delivered to your transmission and eventually to your wheels on the pavement. Your stock crankshaft has counterweights which nullify the force created by the pistons, creating a smooth ride without vibration.
While the factory crankshaft is acceptable for stock-level performance, they are not designed to handle the increased power and abuse from tuning. In fact, the crankshaft is flawed from the factory in four major ways.
The Unwanted Hydrodynamic Brake
As oil is leaving the main bearing caps and being squeezed passed the counterweight, a hydrodynamic brake is formed. This happens whenever a rotating object (such as the crankshaft) is being asked to pass through a fluid (engine oil), and it’s happening in your engine. This unintentional hydrodynamic brake is reducing rotational speed of the crank and consuming horsepower.
Increased Rotational Weight
While the counterweights make for a smoother ride from the factory, they increase the rotational weight of the crank which increases the time it takes for your engine to reach higher RPMs. In addition, factory cranks reduce the spool of turbochargers which decreases overall power.
The third flaw is due to the fact that the crankcase is a pressurized system. The pressure makes it more difficult for the large factory counterweights to pass through the air, further increasing resistance on the crankshaft and decreasing rotational speed. Again, this design is acceptable for a stock engine with an average user, but the effects of the hydrodynamic brake, increased rotational weight and crankcase resistance combined can wreak havoc when you increase the engine’s horsepower.
Risk of Oil Starvation
Last but not least, as the crankshaft rotates in the crankcase oil sticks to the counterweights and is thrown off violently, increasing the time it takes for the oil to reach the oil pan and get distributed elsewhere in the engine. This increases the risk of Oil Starvation, which is exactly how it sounds —oil is not able to flow freely throughout the engine so high-friction parts are not receiving lubrication, which can result in catastrophic failure.
Ultimately, oil starvation is what we consider the biggest risk when using a factory crankshaft. When hundreds, or perhaps thousands of dollars are spent on building a performance engine, the last thing you want is for your factory crankshaft to cause permanent damage.
Why an ISW Competition Crankshaft is Necessary for Your Build
We’ve eliminated the factory flaws that rob your engine of horsepower and increase your risk of catastrophic failure by removing an astounding 4 to 7 lbs from the crankshaft counterweights using our state of the art knife-cut design process.
With the ISW Competition Crankshaft, you can expect:
- Faster rev-times and decreased spool-time (turbo lag), particularly with large frame turbos.
- Increased engine stability at higher RPMs
- Better oil circulation. By removing material from the counterweight, we’ve created an open cavity for the oil to pass through and retreat back to the oil pan and out of the main bearing without coming in contact with the counterweights.
How The ISW Competition Crankshaft is Different
We’ve spent countless hours working with our product development team to offer our customers a superior product. While there may be other lightened crankshafts available, none offer our knife-cut design which guarantees precision on every application. We use the most modern machining technology available which allows us to shave as much material off the crankshaft counterweights as possible while maintaining the structural integrity, ensuring your crankshaft will go above and beyond your expectations for your performance building.
What engines are you making Competition Crankshafts for?
To maintain our high standards for each crankshaft, we are currently only offering the IS Works Competition Crankshaft for 4 Cylinder applications. However, we anticipate expanding this service for 6 and 8 cylinder applications very soon. Stay tuned, as we will be posting updates on our blog and IS Works social media channels as soon as they happen!
Where can I buy one?
At IS Works, customer service is a top priority, so we provide three easy purchasing options in our online store with extremely minimum lead-time for each. See them here.
- Ship us your crankshaft, which we will have completed and ready to ship back out to you in only 10 days.
- Buy a pre-built IS Works Competition Crankshaft and send us your core later. This is an excellent choice for your daily driver.
- Buy a IS Works Competition Crankshaft without sending in a core.
As always, we encourage you to call our experienced sales representatives to learn more. We put our heart and soul into every IS Works original product and we’re always happy to talk about them. Call today at 732-341-3400!
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