Film vs. Boundary Lubrication
Inside a running engine, certain moving parts have the luxury of relying on film lubrication, while other components must make do operating under boundary lubrication conditions. "Imagine skiing behind a boat running 30 mph across the lake, and that is what full film lubrication is like. Now imagine the boat stops moving, which is what a boundary lubrication condition is like," Lake explains. "At low speeds you don't have a full oil film. This is why you see more cylinder bore wear near top dead center on the cylinder bore, as the piston must slow to a stop to change directions. As the piston slows down, the full oil film is lost, and now boundary lubrication takes over. Additives like zinc and moly are the boundary lubrication additives that prevent metal-on-metal contact when the oil film is lost. Since the valvetrain rotates at half the speed of the crankshaft and sees extra load from the valvesprings, the valvetrain of an engine primarily operates in the boundary condition, which means having the correct additives is critical. Higher-rpm engines need different boundary lubrication additives than an engine that rarely sees more than 3,000 rpm. This is why passenger car and diesel motor oils are different from racing oils. Real racing oils are formulated differently to handle the unique boundary lubrication requirements of high-rpm engines."
Formulating an oil requires balancing the properties of the base oil with the properties of various additives. Getting it right is critical to engine longevity. According to Lake, while boundary lubricants like zinc and moly are part of the additive package, the overall additive package is far more complex than just boundary lubricants. In fact, the additive package is typically the most complex part of the motor oil. "A base oil without any additives can provide full film lubrication in an engine bearing if the viscosity is right for the speed and load of the bearing. However, using just the base oil without additives will quickly wear out the rest of your engine," Lake explains. Having the proper balance of additives for the needs of the application is the key to obtaining higher levels of performance and increased engine life. "For example, the additive package for a diesel engine is different from a passenger car engine since diesels create more soot than gasoline engines. Consequently, diesel engine oils contain more dispersant additives to keep the soot from forming sludge. Diesel engine oils are also designed to withstand the higher torque that diesel engines produce. Gasoline engines typically produce less torque and turn higher rpm than diesel engines, so gasoline motor oils are designed differently to accommodate the need for better fuel economy at higher engine speeds. An in-depth discussion of the various detergent, dispersant, viscosity modifier, friction modifier, anti-wear, extreme pressure, anti-oxidant, pour point, metal deactivator, and anti-foam additives and their related chemistry is a whole article by itself! Again, the key is tailoring the blend and balance of these additives to the needs of the application. Unfortunately, just adding more is rarely better."
Whenever a sanctioning body sets a maximum cubic inch limit, the race is on to turn as many rpm as possible without blowing up. The sustained high-rpm of race motors place extraordinary demands on a motor oil. "Higher engine speeds require more valvespring pressure to control the valvetrain. This puts greater loads on the valvetrain contact points, cam, lifters, pushrod tips, and rocker arms," says Lake. "This increased load places more anti-wear demand on the motor oil, so the additive package must be designed to provide fast-acting anti-wear protection. The second demand of high rpm is increased friction in the cylinder bores and bearings. The higher speeds create more friction and heat, so the motor oil must be designed to reduce friction and withstand high temperature. Many oils will breakdown under the higher temperature and friction of high-rpm engines, but real racing formulations actually thrive in these environments since their chemistry works better in these conditions."
Being involved in NASCAR not only serves as a perfect proving ground for Driven motor oil, but it has also instilled a driving spirit that continues to push innovation.
Many hot rodders think that running a low-quality conventional oil on a fresh engine helps seat the rings, but that's not necessarily the right approach to break-in a motor. To assist in the process, Driven has formulated an oil designed specifically for breaking in an engine. "Think about the difference between break-in oil and regular oil as the difference between primer and paint. Break-in oil is like primer for your engine," says Lake. "It establishes the foundation that the motor oil builds off of to protect your engine. Again, the chemistry of a break-in oil is very different than that of a regular oil. Break-in oils are designed to assist the break-in process while still protecting the engine. The worst thing you can do for break-in is to use a poor oil that helps the engine ‘wear-in.' There is a big difference between wearing-in an engine and breaking-in an engine. A properly broken-in motor does not create high levels of wear to get the rings to seat. Using break-in oil like a primer for your engine reduces the amount of wear required to seal up the rings and break-in the valvetrain."