How does the camshaft work?
A camshaft is a rod which rotates and slides against a piece of machinery in order to turn rotational motion into linear motion. This change of motion is accomplished by the camshaft moving further and closer from the axis of rotation as the camshaft is pushed by the machinery.
What are the 4 main functions of a camshaft?
A camshaft is a shaft that contains a row of pointed cams, in order to convert rotational motion to reciprocating motion. Camshafts are used in piston engines (to operate the intake and exhaust valves), mechanically controlled ignition systems and early electric motor speed controllers.
What does camming a motorcycle do?
The basic function of cams is to open and close your intake and exhaust valves. This may seem like a fairly straight forward process, but when dealing with the dynamics of a high speed engine even a minor change can make big differences in performance.
What does a cam do to a dirt bike?
Cams control the opening and closing of the intake and exhaust valves and are as essential to four-stroke performance as cylinder porting is to a two-stroke. Basically, the cam is the brain of the motor controlling what are called the "events" in the valve train.
What are the 2 types of camshaft?
See all 10 photos There are basically two types of camshafts, flat-tappet cams (bottom), and roller cams (top). Within each of these categories, you can opt for either solid or hydraulic lifters.
What are the advantages of camshaft?
It is shown that the principal advantage of overhead camshafts is the increased natural frequency of the valve train. The resulting improved dynamic characteristics of the valve-actuating mechanism make it possible to design camshaft profiles which expand the useful operating range of high-speed engines.
What is a dual OverHead cam motorcycle?
Dual overhead cam engines are found in most modern vehicles today. They allow better airflow with less obstruction and are generally much more efficient engines than OHV or SOHC engines. Two camshafts operate 4 valves per cylinder, one separate camshaft for intake and exhaust valves.
How do I choose a cam for my Harley?
0:104:28How to Choose the Right Cam for Your Harley Davidson - YouTubeYouTubeStart of suggested clipEnd of suggested clipYour riding style is probably the number one factor you need to consider when choosing your cam.MoreYour riding style is probably the number one factor you need to consider when choosing your cam. From there you can go into the plans of what you're going to do to your motor.
What is SOHC in bike?
SOHC is an abbreviation for the term Single OverHead Camshaft setup. Primarily, when a single camshaft controls the opening and closing of both the intake and exhaust valves, then the configuration is referred to as a SOHC setup.
Should cams spin freely?
Take the cam out, take the springs out, the valves out, etc. then put the cam back in. With it like that, it should spin freely. If it doesn't, then you know the problem is with the camshaft and its mounting.
How do you degree a camshaft on a motorbike?
Turn the engine by hand, rotating it until the piston comes up and stops against the piston stop bolt. Look at the degree wheel and write down the number of degrees shown by the pointer. Turn the engine by hand in the opposite direction until the piston comes up and stops on the piston stop again.
How do you check motorcycle cam timings?
Motorcycle Camshaft Timing & AlignmentSet the engine to TDC.Remove the cam chain tensioner.Slide the camshaft through the cam chain.Align the timing marks on the cam with the sprocket and cylinder head.Tighten the camshaft holders.Reset the cam chain tensioner.Confirm the cam marks are properly aligned.
What is a 4 cam engine?
Each camshaft operates two of the valves, one camshaft handles the intake valves, and one handles the exhaust valves. Having four valves per cylinder gives an engine several advantages. By having four valves in a cylinder instead of two, a larger portion of the area can be used to let air in and exhaust out.
What are the key parts of the camshaft?
Following are the main parts of camshaft assembly:Cam bearing journals.Bearing Shells.Lobes.Thrust plate.Chain sprocket.Woodruff key.
What are functions of camshaft and crankshaft?
The camshaft controls the opening and closing of valves through the combustion process, and the crankshaft takes the energy from that process and connects it to the rest of the vehicle.
What are the parts of camshaft?
A camshaft assembly typically comprises of six main parts as given below:Cam Bearing Journals.Bearing Shells.Lobes.Thrust Plate.Chain Sprocket.Woodruff Key.Gear Drive.Chain Drive.More items...
What is the function of a camshaft?
The main function of the camshaft is to open the inlet and exhaust valve of an engine by converting the rotary motion of the crankshaft into recipr...
A camshaft works on which driving mechanism?
A camshaft uses the following three main mechanisms to receive power by the crankshaft: Belt drive mechanismGear drive mechanismChain drive mechanism
Why is a camshaft needed in an engine?
The piston engines can't work without a camshaft. A machine is needed a camshaft for the proper opening and closing of the inlet and exhaust valves.
What is the function of a camshaft?
The main function of the camshaft is to open the inlet and exhaust valve of an engine by converting the rotary motion of the crankshaft into recipr...
What are the applications of a camshaft?
In the reciprocating engines, the camshafts use to close and open the suction and exhaust valves.
What are the signs of a bad camshaft?
The symptoms of a bad camshaft are given below: Vehicle stallingThe vehicle won't startThe vehicle moves slowly.
What is the lift of a camshaft?
The lift of a camshaft is the maximum lift of the valve. You would determine the lobe lift as the amount the lobe increases in radius over its base circle. On the other hand, the amount that the valve raises from its original position is called the valve lift.
Can you neglect a camshaft?
You can never neglect how a camshaft could let the mixture of air and fuel at the right timing. It is basic but essential; without it, you couldn’t keep your wheels moving.
What is the airflow of a camshaft?
There is a little clue here for you sharpies and that is the word AIRFLOW. Airflow is everything and the camshaft is the controller of the airflow. It determines how much, when and how long. The result of all the camshaft specifications is where in the RPM band the motor will make the best power.
Why do stock cams open the exhaust valve?
Stock cams typically open the exhaust valve late (36 BBDC) to maximize the burn time and pass emission tests easier...but suffer from pumping losses because the piston has to work harder to mechanically push out the burnt gases. If the cam opens the exhaust valve a little sooner (40-43 BBDC), we can use blow-down (the expansion of burning A/F) to help scavenge the cylinder. This gets the burnt gases moving, reduces the piston effort, and decreases pumping losses...up too about 4000 RPM. However if the cam opens the exhaust valve too soon ( 45+ BBDC) the blow-down will bleed off much of the expansion pressure of the power stroke from idle thru about 2500 RPMs. The RPMs must be higher to overcome the time available for blow-down.
How does LSA affect idle quality?
Generally, smaller lobe separation angles cause an engine to produce more mid-range torque and high RPM power, and be more responsive, while larger lobe separation angles result in broader torque, improved idle characteristics, and more peak horsepower.
Why do you need an exhaust valve opening?
Later exhaust valve opening helps low RPM performance by keeping pressure on the piston longer, and it reduces emissions.
How does opening an exhaust valve affect engine performance?
Opening the exhaust valve to early decreases torque by bleeding off cylinder pressure from the combustion that is used to push the piston down. Yet the exhaust has to open early enough to provide enough time to properly scavenge the cylinder. An early opening exhaust valve may benefit scavenging on high-RPM engines because most useful cylinder pressure is used up anyway by the time the piston hits 90-degrees before BDC on the power stroke.
How does the intake closing point affect the engine?
The intake closing point has more effect on engine-operating characteristics than any of the other three opening and closing points. The earlier it occurs, the greater the cranking pressure. Early intake closing is critical for low end torque and responsiveness and provides a broad power curve. It also reduces exhaust emissions while enhancing fuel economy. As RPM increases, intake charge momentum increases. This results in the intake charge continuing to flow into the combustion chamber against the rising far past BDC. The higher the engine's operating RPM, the later the intake closing should be to ensure all the charge possible makes it into the combustion chamber. Of course, closing the valve too late will create significant reversion. It's a fine balancing act. In a perfect world, the optimum intake closing point would occur just as the air stops flowing into the chamber. It would get the valve seated quickly and not waste time in the low lift regions where airflow is minimal and there is no compression building in the cylinder. It wouldn't be so fast the valve bounces as it closes, allowing the charge to escape back into the intake port and disturb the next charge; and in hydraulic street cam applications, it would insure that the closing ramps are not so fast that they result in noisy operation.
What do you need to know about cams?
Cams Explained... What you need to know about Cams. #1 - the most common camshaft error made by people is to OVER cam the engine. #2 - is selecting a cam that is not compatible for the RPM range that we plan to operate the engine in. There are a number of things, which affect the cam’s performance. Cylinder head flow rates: The cylinder heads must ...
How does Camshaft work?
The main objective of the camshaft is to open the suction valve and exhaust valve at the appropriate time. The crankshaft drives to this shaft. It is linked with the crankshaft through a belt or meshing gears.
What is a camshaft?
A camshaft is a rod that mechanically turns to convert rotary motion into reciprocating motion.
What is a cam follower?
It is a special type of needle bearing or roller that follows the cam lobe profile. It is also called track follower. There are different configurations of the cam follower, but the most important feature is the attachment of the cam follower to the mating part. The yoke cam follower has a hole in the center, and the stud cam follower uses stud.
How many rollers does a camshaft have?
It has 2 rollers. The follower or driver of this camshaft is linked with these rollers. The rollers tend to limit the movements of others so that they cam remove noise and produce quiet operations.
Why do crankshafts and camshafts move in the same direction?
It uses a chain tensioner to prevent the chain system from coming loose because loose chains cannot transfer sufficient power from the crankshafts to the camshafts.
What is the purpose of camshaft lobes?
The speed of this component varies according to the speed of the engine. The main objective of the lobes is to open and shut the inlet and outlet valves.
What is a gear drive?
The gear drive mechanism is used where is a required minimum distance between the crankshaft and camshaft. In this mechanism, a gear drive method uses to deliver the crankshaft’s power to the cam.
How do cams work on motorcycles?
Inboard cams regulate the work of its valves by moving pushrods and activating rockers so that the valves can open at the right time and stay open for the right period. Overhead cams are installed over the valves and push them directly in the cylinder head. This eliminates the need for additional moving parts in the forms of pushrods and rocker arms thus making it easier to achieve higher revolutions and produce more power. The operation of the motor largely depends on how far the valves are lifted, so the installation of an improved camshaft is a great way to start modifying your engine.
How does a DOHC camshaft work?
The DOHC version of the camshaft utilizes the direct actuation of the valves which allows for higher engine revolutions. That is why this layout is most often used in sportbikes. To choose the right aftermarket camshaft that fits your engine and riding style, you have to know three main specifications: lift, duration, and intake closing time. Lift defines how far the valve moves from its seat when it is opened. The farther the valve goes, the quicker the air-and-fuel mixture can enter and exhaust gases can escape the cylinder. It means that more fuel can be burned in the combustion chamber thus increasing the output of the engine.
What camshafts are used in Indian 111 engines?
Camshaft by Andrews Products®. Indian 111 engines are already a performance favorite. Installing a set of three new Andrews cams is the best way to more power. All Andrews cams use Landis CNC cam grinders and computer-designed lobes.
How do inboard cams work?
Inboard cams regulate the work of its valves by moving pushrods and activating rockers so that the valves can open at the right time and stay open for the right period. Overhead cams are installed over the valves and push them directly in the cylinder head.
How to increase horsepower on higher RPMs?
If you want to increase the horsepower of your engine on higher RPMs, consider installing a cam with later intake closing time. It is most suitable for larger, high-compression motors. Lower-compression engines work better with cams offering short intake duration and early intake closing time.
What is the job of a camshaft?
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.
What is a camshaft sensor?
A camshaft sensor feeds information to the engine about the components and conditions of the air, fuel and spark ignition.
How does a valve timing mechanism work?
A mechanism can slide the whole camshaft laterally so that the valve engages different parts of the cam. The shaft still spins just like a regular camshaft -- but by gradually sliding the camshaft laterally as the engine speed and load increase, the valve timing can be optimized.
How does a Ferrari cam work?
The camshafts on some Ferrari engines are cut with a three-dimensional profile that varies along the length of the cam lobe. At one end of the cam lobe is the least aggressive cam profile, and at the other end is the most aggressive. The shape of the cam smoothly blends these two profiles together. A mechanism can slide the whole camshaft laterally so that the valve engages different parts of the cam. The shaft still spins just like a regular camshaft -- but by gradually sliding the camshaft laterally as the engine speed and load increase, the valve timing can be optimized.
What are the different types of camshafts?
There are several different arrangements of camshafts on engines. We'll talk about some of the most common ones. You've probably heard the terminology: 1 Single overhead cam (SOHC) 2 Double overhead cam (DOHC) 3 Pushrod
Why do engines have double overhead cams?
The main reason to use double overhead cams is to allow for more intake and exhaust valves.
What is a pushrod engine?
A pushrod engine. The camshaft in a pushrod engine is often driven by gears or a short chain. Gear-drives are generally less prone to breakage than belt drives, which are often found in overhead cam engines. A big thing in designing camshaft systems is varying the timing of each valve.
What is the airflow of a camshaft?
There is a little clue here for you sharpies and that is the word AIRFLOW. Airflow is everything and the camshaft is the controller of the airflow. It determines how much, when and how long. The result of all the camshaft specifications is where in the rpm band the motor will make the best power.
How to tell the difference between a woods cam and a S&S cam?
which translates into more area under curve to flow and thats the key which would transfer into more power longer but also requires heavier spring than the S&S in this case it may be minimal but something to be aware of.
What does tight LSA cam mean?
The tighter LSA’s are, the more likely problematical exhaust reversion into the intake will occur. Put simply, we can say that a tight LSA cam produces a power curve that is, for want of a better description, more "punchy.". At low rpm when off the cam, it runs rougher, and it comes on the cam with more of a "bang.".
What degree does a street cam lobe split?
The same principle applies with separation on cam lobes. Typically, lobe separation for street cams runs between 97 and 108 (camshaft) degrees. The relationship between intake and exhaust is ground into the cam and can’t be altered by advancing or retarding the overall cam timing.
How does LSA affect idle quality?
Generally, smaller lobe separation angles cause an engine to produce more midrange torque and high rpm power, and be more responsive, while larger lobe separation angles result in broader torque, improved idle characteristics, and more peak horsepower.
How does the intake closing point affect the engine?
The intake closing point has more effect on engine-operating characteristics than any of the other three opening and closing points. The earlier it occurs, the greater the cranking pressure. Early intake closing is critical for low end torque and responsiveness and provides a broad power curve. It also reduces exhaust emissions while enhancing fuel economy. As RPM increases, intake charge momentum increases. This results in the intake charge continuing to flow into the combustion chamber against the rising far past BDC. The higher the engine's operating RPM, the later the intake closing should be to ensure all the charge possible makes it into the combustion chamber. Of course, closing the valve too late will create significant reversion. It's a fine balancing act. In a perfect world, the optimum intake closing point would occur just as the air stops flowing into the chamber. It would get the valve seated quickly and not waste time in the low lift regions where airflow is minimal and there is no compression building in the cylinder. It wouldn't be so fast the valve bounces as it closes, allowing the charge to escape back into the intake port and disturb the next charge; and in hydraulic street cam applications, it would insure that the closing ramps are not so fast that they result in noisy operation.
Why open intake valve?
Intake Opening: Looking at the intake valve, its opening point is critical to vacuum, throttle response, emissions, and gas mileage. At low speeds, and high vacuum conditions, premature intake opening during the exhaust stroke can allow exhaust gas reversion back into the intake manifold, hurting the intake pulse velocity, and contaminating the fresh intake charge. A late opening intake gives smooth engine operation at idle and low RPM, and it ensures adequate manifold vacuum for proper accessory operation (assuming the other three valve opening and closing points remain reasonable). As RPM increase, air demand is greater. To supply additional air and fuel, designers open the intake valve sooner, which allows more time for the intake charge to fill the cylinder. With an early opening intake valve, at high rpm, the exiting exhaust gas also helps draw the intake charge thru the combustion chamber and out the exhaust - that's good for purging the cylinder of residual gas, but it also increases fuel consumption by allowing part of the intake charge to escape before combustion and can make for a rough idle.
How does a decompressor work in a motorcycle?
What Is A Decompressor and How It Works In Motorcycles. In any internal combustion engine, the fuel and air mixture gets ignited and power is generated. But in the entire process there is one more thing that helps in the process and that is pressure. This pressure is created due to the compression in the combustion chamber by the piston.
How does a decompression valve work?
Now a days the way decompression systems are designed is simply by connecting one of the exhaust valves using a cable similar to a clutch cable, so when starting up if there is any issue encountered that need decompression, the cable gets yanked up a little and the exhaust valve opens up just a little to give a little breathing space allowing for the engine to work properly. And that is how decompression works.
What happens when you start a bike with a starter?
So when the starter is applied, more air and fuel mixture enters inside the combustion chamber and causes extra compression than required. So if this compression exceeds the level that the bike is designed for, then there are chances of the engine to burst altogether and that is very much fatal. So to take care of that problem, one of the exit valve is designed in such a way as to open a little bit to allow some more breathing space and let the compression level fall a bit and the engine can start up properly.
What causes a bike to turn in the opposite direction?
The turning of the engine can make the crankshaft sometimes turn in the opposite direction of normal movement and this event is more tend to happen with 2-stroke engines. This would not be a problem generally, but when put into gear, the bike would move in the opposite direction.
Why is it important to reduce compression?
But sometimes it so happens that this compression can get fatal or inefficient for working purposes and there is a need for the pressure to be released a little which is called decompression. You reduce the compression or the pressure inside the chamber for everything to work well. This is generally needed at certain times like during the initial ignition of the engine start up. During the first start there is already pressure buildup due to end of the engine running in the previous cycle of running.
