Different vehicles have different engines and that’s nothing new but the way the power generated from the combustion process affects everything else can vary too. Take the camshaft for example, different configurations can make it act differently.
For instance, with OHV or overhead valve engines, you have the camshaft placed close to the lower end of the piston where it connects to the crankshaft instead of being sitting above the valve(s). This makes OHV engines use what is known as a pushrod which helps transfer that movement to the lifter making it open up at the right time.
Kit Components
Bolts
When it comes to replacing or upgrading your OHV engine’s camshaft the first and most underrated piece of hardware are bolts. Almost everything in the engine is held by bolts or some kind of fasteners and camshaft head bolts are one of them. These connect the cylinder head to the block of the engine and alongside the pistons and cylinders the cylinder head also typically houses the camshaft. They are quite long and usually have a hexagonal head. Head bolts can be either angular or standard.
Standard ones are not able to provide equal pressure across the entire cylinder head. This means they should be re-tightened when the engine warms up. Angular cylinder head bolts are much better since they don’t need to be re-tightened which is why they are more common nowadays. Other types of bolts you’ll get in a camshaft kit are those used to hold the harmonic balancer.
The harmonic balancer helps absorb the vibrations from the engine which not only makes the driving experience smoother but it also prevents anything coming loose connected to the crankshaft pulley. These bolts are used together with washers in order to keep the balancer in place as otherwise there can be issues with the alternator, transmission and power steering pump. As you can imagine both balancer camshaft bolts and cylinder head bolts are quite important despite being simple fasteners.
Pushrod Set
If you have an older Holden or any American car of the same age it most likely has a pushrod inside the engine. Together with a rocker arm, the pushrod is actuated by the camshaft’s lobes so that it opens up the valves in the combustion chamber.
This simple yet crucial component is found in a car camshaft kit and it’s known as a pushrod set. A pushrod set contains the exact number of rods with the exact dimensions that the manufacturer has intended for the engine. The number of pushrods depends on the number of cylinders found in the engine.
Cam Gear
Another crucial part of a cam kit is the cam gear. This gear is usually held on by 3 bolts and it’s driven either by a belt or a chain. When the crankshaft moves it moves the belt that connects the cam gear and other components which makes the camshaft move.
Camshaft
The camshaft itself is the last and most important component in this kit as it’s what drives the opening and closing of the valves in each cylinder. Thanks to their different sized lobes they can speed up or slow down the opening of each valve which affects performance and efficiency.
Common Camshaft Issues
Wear & Tear
One of the most common reasons for camshaft failure is worn-out components. Each engine part has a certain lifespan and the same goes for cam lobes and springs. This can slow down your vehicle and make it feel sluggish.
Sensor
Modern engines have sensors all around but even older OHV engines have sensors and one of them is for the camshaft. This sensor helps synchronise the operation of the camshaft with the crankshaft and if it fails it can make the engine have ignition issues.
Sync
This de-synchronisation can happen at a greater scale if the cam’s timing belt is not installed properly. This could also happen if the belt is starting to wear and lose grip which can end up in catastrophic damage if not replaced on time.
Lubrication
Almost every moving part in the engine needs to be lubricated and the same goes for the camshaft and its surrounding components. But luckily this is easily done as all you need to do is make sure that the engine oil is not below the recommended level shown on the dipstick.
Break-In
Each car camshaft kit comes with a manual that tells you how to properly break in the new camshaft. If not done the correct way the engine can experience issues such as premature wear and inconsistent idling.
Torque Spec
The hardware that comes with a new car camshaft needs to be torqued to the correct spec. Just like any fastener in the engine, those surrounding the camshaft need to be torqued with a torque wrench. Impact guns are out of the question as you can easily over-torque the fastener and damage it.
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