What Gives A Cam A Lopey Idle?

What makes a cam sound lumpy?

Also know, what makes a cam sound lumpy.

The overlap of the exhaust valve closing and intake valve opening causes the engine to be inefficient at low speed which results in the lumpy idle.

The closer the Lobe Seperation Angle the more the overlap, the more duration the more (typically) the overlap..

What Cam can I put in a stock 350?

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How do I check my cam timing?

Begin as you did before with a dial indicator on the lobe of the cam. This time, however, position the cam so the dial indicator is sitting on the base circle (zero lift) and zero out the dial. Rotate the engine in the normal direction of rotation until you have 0.050 lift and look at your degree wheel.

What does a new cam do?

The camshaft uses lobes (called cams) that push against the valves to open them as the camshaft rotates; springs on the valves return them to their closed position. This is a critical job, and can have a great impact on an engine’s performance at different speeds.

Is it bad to Cam your car?

A car’s camshaft is located beneath the engine and provides the important function of opening and closing the valves of an engine. When something goes wrong with a camshaft, your car can stall more, accelerate more slowly, or even fail to run altogether.

Does a cam increase compression?

Overlap causes a “scavenging effect” as the engine RPM increases. This is why performance cams “come alive” at higher RPMs. It’s not “just” the cam making the power, it’s the cam’s scavenging effect working as the RPM increases which increases cylinder pressure (dynamic or effective compression).

Does a cam increase horsepower?

Performance cams increase the duration and timing of the valve openings during the engine stroke, increasing horsepower and making your car accelerate more quickly. You’ll idle slightly rougher with a performance cam, but get a throaty rumble that’s desirable for some gearheads, depending on your vehicle.

How do I get a cam lope?

Overlap causes misfires at idle and that makes the lope or choppy idle. It causes a lot of intake reversion which causes the engine to basically choke on it’s own exhaust during idle. The more the overlap the more the lope will be.

How do you check camshaft timing?

To confirm accuracy, you need a dial indicator with a measuring range of at least 1 inch on each lifter. With both valves closed, set the dial indicator at zero. Begin with the intake valve; slowly turn the crank clockwise until the lifter rises 0.050 inch. Stop turning the crank and read the degree wheel.

What happens if cam timing is off?

If the engine timing of the cam is off, your car will either be running rough or not at all. If the ignition timing is the problem, it isn’t as easy to notice because it has four cycles: Intake valve sucks in air while fuel is delivered by the injectors. The fuel mixture is reduced.

What does lobe separation do for a cam?

The lobe separation angle is the angle in camshaft degrees between the maximum lift points, or centerlines, of the intake and exhaust lobes. It affects the amount of valve overlap; that is the brief period of time when both the intake and exhaust valves are open.

What does a 4/7 swap Cam do?

If the engine gets a 4-7 swap cam, then #3 and #7 fire consecutively and go into the same collector and #2 and #4 fire consecutively and flow into the same collector. Therefore, a 4-7 swap changes the exhaust dynamics on both sides of the engine.

Does a cam change the sound?

Cams will change the sound of any exhaust because of the new valve timing.

Does a cam make a car louder?

A cam can make an engine louder. I’ve done extensive testing in an anechoic chamber with a motoring dyno driving a non firing engine with working cylinder heads but no pistons. When you change cams you have probably changed the angle of the grind on the cam. Sometimes this will affect closing velocities of the valves.