Question: What Makes A Cam Lumpy?

Can Cam timing affect compression?

Yes, the timing of the closing of the intake valve effects compression pressure.

There are two different compression ratios, static and dynamic.

The static is based on a full cylinder and ignores valve timing, the dynamic is based on the stroke after the intake valve is closed..

Does retarding the cam timing increase compression?

Since the timing is not ideal for say 800 RPM, retarding the timing might improve the actual compression. Again cam timing is a compromise. If you set the cam up to open so it runs best at 800 RPM, the engine won’t run as well at 2500 RPM.

Does a cam change the sound?

cam controls the valve action and timing. better cylinder filling = more compression, bigger BOOM sound. engine is louder. simply put.

What is the advantage of a roller cam?

Roller cams also allow for steeper lobes. In other words, they allow for more “area under the curve.” This means the valve opens faster and remains at a higher lift for a longer period of time. This allows for more airflow and more power. When changing cams, roller lifters can be re-used.

How do you find an engine cam?

How to Identify a Camshaft by NumberFind the model prefix. The model prefix is the first part of the camshaft number, and it describes the vehicle that the camshaft is meant for. … Find the profile or grind number. This number should be on your camshaft, followed by a number of degrees. … Find the exhaust number and add it to the end of the list of numbers.

How does LSA affect idle?

A wide LSA reduces valve overlap, softens the idle and improves overall drivability–especially on the street where performance engines benefit from 112 to 114 LSA. … Nitrous engines, which make plenty of power and torque, often run wide lobe separation angles to moderate cylinder pressures and temperatures.

What does a lumpy cam mean?

A;you know what a stock car sounds like at idle, well a lumpy cam sounds like a miss or a race car idling. B; a race cam (one thats usually too big for a stock motor) or a big cam for a worked motor is usually refered to as lumpy. Edit; what it does, sounds tuff and goes hard.

What are the bumps on the camshaft called?

A camshaft lobe is an eccentric that converts rotating motion into linear (up and down) movement. To do this, a lobe, or bump, is created from a true circle known as the base circle of the cam—also known as the heel.

What do the 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.

Does a cam increase horsepower?

Consider installing a performance camshaft. Performance cams increase the duration and timing of the valve openings during the engine stroke, increasing horsepower and making your car accelerate more quickly. … Adjust the timing and tweak the new cams as necessary.

What does LSA stand for engine?

opening (and closing)The exhaust opens before the intake during the “standard” engine cycle (firing to firing). So increasing the LSA means opening (and closing) the exhaust EARLIER with respect to when the intake is opened.

Can you cam a diesel?

Camshaft Lubrication Issues Most diesel engines, with some exceptions such as Duramax and some late model Caterpillar and International engines, still use flat tappet camshafts with flat bottom valve lifters rather than roller lifters.

What’s considered a mild cam?

A mild cam is primarily strip but might see some street action. A “weenie” cam is suitable for the street but some would consider it on the edge.

What is cam angle?

A. During which the follower returns to its initial position. Of rotation of the cam for a definite displacement of the follower. Through which, the cam rotates during the period in which the follower remains in the highest position.

How much horsepower does a cam add to a 350?

Say you put that Edlebrock Performer intake on your engine with the stock cam and you will pick up about 15 hp, over stock, however, if you put that same intake and carb on your new cam, you could pick up 20 hp from it.

How much horsepower does a cam and heads add?

A normal bolt on car with a cam can usually go 390-440 depending on the choice of cam and bolt ons. A head/cam car can usually make 425-475 depending on the set up, though there has been set ups getting close to the 500 mark. To me the most fun is a cam car with N20.

Should I advance my cam?

One way to improve the low-speed torque on a camshaft with too much duration is to advance the intake lobe in relation to the exhaust. Advancing just the intake lobe opens and closes the intake valve sooner which is one way to help improve the low-speed torque.

Can you cam a stock engine?

Guest. there is no reason to swap cams into stock motor…. just a waste of money …..the performance if any would not justify the effort and expense…. the stock heads & intake need to be replace prior to a cam upgrade due to their restrictive nature to gain any performance advantage…

How is cam centerline calculated?

To find the intake lobe centerline, divide the intake duration by two and subtract the indicated intake opening point as shown in our example with the Comp XE274 example. Sometimes you find a very mild or stock cam where the IO occurs after TDC (ATDC). In this case just add the IO figure to one half of the duration.

Can you cam a v6?

You can re-cam you V-6, but it will turn into a lot of money to do it correctly, actually a total engine rebuild since you are nearly tearing down the upper half of your engine. New or totally reworked heads, new exhaust and computer re-programming, and smog testing finger crossing.

What does LSA on a cam mean?

LSA is the distance from the centerline of the intake lobe to the centerline of exhaust lobe. It is the average centerline between both lobes and expressed in degrees ranging from 95 on the extremely narrow/tight side to upward of 120 on the wide end.

What is high lift camshaft?

Designing a cam profile with more lift results in increased duration in the high-lift regions where cylinder heads flow the most air. Short duration cams with relatively high valve lift can provide excellent responsiveness, great torque, and good power. But high lift cams are less dependable.

How much HP does a cam and headers add?

It depends on the cam specs and downstrean exhaust from the headers. Low back pressure catalytic converters and flow master Mufflers. Depending on the grind, overlap, duration and degree of installation with the above exhaust your looking at from 15 to 50 HP without changing injectors.

What makes a cam sound choppy?

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. Lope is a result of the intake and exhaust valves both being open at the same time. …

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 Big Cam mean?

When someone refers to a “big cam,” they mean it has longer duration, not higher Lift. Manufacturers often list 2 different duration values: Advertised Duration is the degrees of crankshaft rotation that the lifter is raised more than a predetermined amount. … You should use this value to compare camshafts.

Is a crankshaft the same as a camshaft?

A camshaft uses egg-shaped “cams” to open and close engine valves (one cam per valve), while a crankshaft converts “cranks” (the up/down motion of the pistons) to rotational motion.