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    Producing Quality Computer Tools for Racers and Engine Builders since 1986






Cam Profile

Camshaft Basics

The camshaft is your engine's "mechanical computer".  It controls the opening and closing of the valves which is critical to how your engine will operate.  Change the camshaft and your engine can become a high MPG highway cruiser, and high torque high climber, a high revving circle track engine with a broad power band, or a "peaky" drag racing motor. The most important part of your camshaft are the lobes. As the camshaft rotates, the lobes open and close the valves via the follower which "rides" on these lobes.

Univ Flat on Lobe showing Index.jpg (89356 bytes) (click image for picture of cam lobes being measured on our Cam Test Stand)

While the intake valve is open, the piston starts its intake stroke by sucking the air fuel mixture into the cylinder by the piston moving down. The mixture is moving at a very fast rate while this is happening. The faster the engine is spinning the longer the intake valve should stay open. This is controlled by valve lift which is directly related to the cam lobe profile.

Then at some point the intake valve closes and the piston starts moving back up the cylinder. This compresses the air fuel mixture where it is ignited and the explosion forces the piston back down. When the piston gets close to the bottom of the cylinder the exhaust valve opens to let the waste gases out while the piston is moving back up the cylinder. Then it starts all over again.

Variable Valve Timing

Now, any camshaft will perform perfectly at a certain engine speed. But at other speeds the engine will perform at a lower level. Therefore, a fixed camshaft will always be a compromise. This is why engine makers have worked on ways to vary the cam profile as the engine RPMs change using Variable Valve Timing.

Programs and Tools that work with Cam Profile:

Performance Trends has programs that can record Cam Profiles (Cam Analyzer v3.8) or Simulate how a particular Cam Profile will affect your engines performance (Engine Analyzer Pro v3.9).

And we manufacture our Cam Test Stand that holds and measures your Camshaft so the information can be automatially imported into Cam Analyzer.