Quick Answer: How Do You Get A Lopey Idle?

How do you fix a surging idle?

The cure for this condition is to clean the valve with some aerosol throttle cleaner or engine top cleaner.

Here’s how to clean the IAC valve: Disconnect the air intake ductwork from the throttle body.

Start the engine, then increase and hold the idle speed to 1,000 to 1,500 rpm..

What is lopey idle?

What does lopey idle mean? The idle lope comes from changing the duration of intake and exhaust valve overlap, usually so that the intake valve stays open a little longer and or the exhaust valve opens earlier. That’s easy to do on a the 5.0 (with the computer) because the intake and exhaust cams are separate.

What is a good camshaft duration?

Cams with durations in the 195 to 210 degree range (measured at . 050˝ cam lift) are usually considered best for stock unmodified engines and those with computerized engine controls. … A cam with a duration of 240 degrees of higher will typically produce the most power from 3,500 to 7,000 rpm.

What causes RPM to fluctuate while idling?

Why does my engine’s RPM seem to fluctuate (runs rough)? Engine hunting and surging at idle is usually caused by a fuel delivery, air leak, or governor system problem. Cleaning/overhauling the carburettor, adjustment of the governor, and/or changing the air filer may be required.

How much horsepower does a cam add to a 350?

Replacing the 2G with a Q-Jet and intake alone can be worth 25-30 hp. Toss in a mild cam and cylinder head upgrade and the power gains really start to add up.

Is a ghost cam tune bad for engine?

There’s nothing wrong with a ghost cam tune, plenty of people running it with no problems. Unless you’re auto, then it’s probably not a good idea due to the effect it has on drivability.

Why do cars idle rough?

Two reasons. First they have a camshaft setting that gives plenty of power and efficiency at high rpm, at the expense of power and efficiency at low rpm. And of course idling is the lowest rpm, so the car idles roughly with a bit of a misfire. Second, muscle cars tend to have more open exhaust systems.

What is considered a mild cam?

A mild cam is usually a little bigger than the stock cam. Most of the “Mild” cams have just a bit of lope to them and will give you a bit more power than the stocker. My car, unfortunately, has a mild cam in it with it’s TR224. Still makes more power than stock but idles and rides real close to stock.

What is a good cam for a stock 350?

COMP Cams CL12-600-4 Camshaft For 350 Chevy – Best Top Pick Review. COMP Cams CL12-600-4 camshaft option is our top pick, and for good cause. With its many great features that will increase the performance of your 350 Chevy significantly, this choice will give you the most horsepower for the most cost-effective price.

How do you get a lumpy idle?

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 causes an engine to lope?

A compression leak may come from a cylinder head gasket and cause the engine to lope sometimes. This usually happens because the engine has high mileage, or a particular failure, like overheating, caused the gasket to blow.

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.

What cam specs mean?

The definition is simply the distance in degrees, as measured on the cam, between the point of peak lift on the intake lobe and the peak lift on the exhaust lobe. … Some given measurements, such as lift and duration, are easy enough for even the neophyte camshaft connoisseur to understand.

What is the best camshaft brand?

According to our BrandZoom Camshafts report, based on surveys of automotive enthusiasts who have shopped for or purchased a cam, the top 3 brands that are most trusted are COMP Cams, Crower and Edelbrock (in alphabetical order). Each of these three had a 90% or higher positive perception.

What is the biggest cam for stock 350?

What is the biggest cam for stock 350? The biggest cam will be the COMP Cams CL12-600-4 Thumpr 227/241 Hydraulic Flat Cam. This can also be regarded as the best cam for stock 350 chevy.

Does 20 horsepower make difference?

15-20 HP extra in a car that normally has approx 100HP at the wheels will make 15-20% difference!

How does lobe separation affect idle?

In conclusion, lobe separation angles change the amount of valve overlap, which affects many performance factors particularly idle quality, peak torque that can be moved from a lower rev range to a higher range and power bands that can be narrowed or broadened. Narrow Angle (104 degrees) means: Lower rpm torque range.

What does a lumpy cam mean?

The lumpiness of the cam is usually described by the manufacturer’s as the lope at idle. A rough lope at idle is usually a very lumpy cam as they are operating way outside their optimum operating range at idle, i.e. 5,000 – 9,000 RPM operating range (way to big for normal road use).

What gives a cam a lopey idle?

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.

Why does my car rev up and down while idling?

The idle is controlled by the idle air control valve and if it cannot keep the engine idling it will keep trying to rev the engine up to compensate. A vacuum leak, sensor that has failed, or an EGR system malfunction could potentially be the cause of the erratic engine you’re experiencing.