What Does the Expression: "On the Cam" Mean?

[SeldomSeen]

I've heard this referring to when a car is going quickly but what is going on in the engine

[RoyBatty]

Simply put, it means the engine has been spun up to a point that it has come into the sweet spot of its power band where it starts to pull in a strong fashion.
This point is affected by gear ratios and engine setup.

[maytag]

Simply put, it means the engine has bees spun up to a point that it has come into the sweet spot of its power band where it starts to pull in a strong fashion.
This point is affected by gear ratios and engine setup.

This explanation is exactly right. To further explain the etymology of the expression; the cams duration, overlap and (to a lesser extent) lift are the most important factors in determining at what RPM range the motor gets into the fat part of the power band. This "fat part" is therefore "on the cam".

[SergeantSavage]

Those guys are exactly right and I will add to it like this: The camshaft (or camshafts) are generally designed for street driveability in street cars. If you have ever heard an old American V8 with a 'lumpy' idle, a tradeoff has been made. Maybe a little harder to start when cold and harder to drive at low rpm's.. BUT when it all comes together at a higher speed and the engine is running where it is happiest with that cam, it makes more power that it would at that rpm with a more street friendly cam.

VVT (variable vale timing) such as the Honda VTEC and many others nowadays, utilizes an electric and/or hydraulic mechanism to shift cam timing/lift/duration (think of a cam with two sets of lobes) at preset rpm's in order to keep the engine always 'on the cam'.

Just rambling..haha. Does that make any sense?

[SeldomSeen]

'Got it. Thanks all. I had some fine times back in my old Judo days when everything was "on the cam." Ah the good old days.

[RoyBatty]

Also, you may hear some folks use the expression "on the pipe".
Same kind of thing, but more often used in reference to two stroke engines.

[bobplyler]

And there is an expression for 2-stroke motorcycles. It's called "on the pipe". That means that the bike is in the region where the most power is. If you've ever ridden a two stroke motorcycle when it gets on the pipe, hang on. The Kawasaki Mach III was a notable example of this.

[124JOE]

on my RC nitro cars and boats you shorten the exhaust pipe for lower power"take off"just 1/4 inch
and make it longer for top speed runs up to 1/2 inch thats from stock