The internal combustion engine has been around for well over a hundred years. Providing power for countless vehicles and other applications, the engine as we know it is a part of our daily lives. One of the more popular internal combustion engines is a 4 stroke engine. Pretty much every automobile has one in it, save for pure electric cars at least.
If you are a car nut, you likely know what a camshaft does. You probably even have at least a general idea what it does. Lunati of Olive Branch, Mississippi builds hot rod camshafts and has set out to educate their customers on nearly every aspect of camshafts, including the basics of how they work, terminology associated with them and into heftier technical information such as how to degree a camshaft and verifying your valvetrain geometry.
An engine camshaft is a length of steel with a given number of lobes designed into it that are specifically clocked and positioned to either directly or indirectly operate valves used for intake and exhaust purposes. Each lobe is ground to exacting specifications so as to allow the engine to operate at optimum performance. The lobe can either be symmetrical, where the profile is exact from left to right or they can be asymmetrical, meaning the sides differ from each other. The lobes have several different parts to them including the Base Circle, the Flank and the Nose. Lobe Lift is the distance from the very tip of the lobe to the edge of the adjoining side of the base circle. The lobe lift determines the operations of the valve opening and closing. Lunati notes on their website that “generally, opening the valves quicker and further will increase engine output.”
Every bit of the lobe shape and location on the camshaft is important. Duration is handled by the shape and determines how long the valve is open. Adjustments made to the duration can potentially increase power output at higher RPM. Lobe separation on the other hand is the angle at which each the maximum lift points between intake and exhaust valves. A tight lobe separation is 106° to 109° whereas a wide lobe separation is 110° to 118°. “Lobe separation affects valve overlap, which affects the nature of the power curve, idle quality, idle vacuum, etc.” explains the Lunati website.
The camshaft lobe handles the air and fuel getting in and the exhaust fumes going out. That is a pretty intergral part of how the system works and how our hot rods scoot us down the roads. Lunati has dedicated themselves to producing the best products possible. Ties into multiple racing sanctions helps keep the company on its toes for pushing the limits of known camshaft technology. The company also knows how camshafts need to be built for different desired results. Lunati offers camshafts designed for Street/Strip hot rods, High Efficiency units for improved fuel comsumption, EFI Compatible units that maximize the RPM powerband of computer controlled performance engines and many more.