Quick Tips on Getting a New Camshaft
Your camshaft, sometimes called the "brains" of your engine, manipulates the valves that allow fuel and air into your engine. Your vehicle simply won't function without it, and the kind of camshaft you get determines engine qualities ranging from how much power and performance you can get to how well your engine idles. Picking out the right camshaft can be quite complicated. If you're looking to replace your camshaft with something other than the exactly the same type you started out with, here are some things you need to know:
Camshafts are usually made out of either of two types of material: chilled iron castings or billet steel.
- Chilled iron castings - This is the most common type. The chilling process makes the material harder. That, and elements added to the iron used, make for very durable camshafts for most driving applications.
- Billet steel - This is used only for very high-quality camshafts. A special heat-treating process called gas nitriding is used to make the steel extremely hard. This type of camshaft is much more expensive and is used for high-performance engines.
There are four basic types of camshafts. The type is determined by whether it's a roller camshaft or a flat tappet camshaft, and whether each type uses a hydraulic or a solid lifter.
- Flat tappet camshafts - These use a lifter with a slightly curved bottom sliding against the cam lobes. The curved bottom helps reduce friction. Flat tappet camshafts were in almost every V8 engine produced the late 1980s. They are still quite common and are relatively much cheaper.
- Roller camshafts - With a roller or wheel rolling over the cam lobes, the amount of friction and wear is greatly reduced in these camshafts. Roller camshafts provide better performance by allowing for more mid- to top-end power without compromising bottom-end power. These are much more expensive than flat tappet camshafts.
- Hydraulic lifters - These automatically adjust the valve lash (the distance between the valve stem and rocker arm tip) as needed. They are quieter, require almost no maintenance, and cause much less wear on the valvetrain. The only problem is how they may overfill with oil, causing the valves to stay open too long at high rpm. This can lean to engine damage at high speeds.
- Solid lifters - These are more ideal for racing since they don't have the oil-overfill problem of hydraulic lifters. However, they are also noisier and require periodic adjustment of the valve lash.
Other things to consider:
- As always, your vehicle's owner manual is a good place to start looking for information regarding any parts you plan to get for your vehicle.
- Your replacement camshaft must be compatible with your engine's cylinder head. Know the exact specifications of your cylinder head (make, model, size of intake/exhaust valves, etc.) and see if the camshaft you're getting can work with them.
Serious Engine Surgery: Replacing Your Camshaft
Your camshaft keeps your car running by manipulating the valves that allow fuel into your engine. This is a vital component as your vehicle simply won't run without it. Should your camshaft get damaged, you will have no choice but to replace it right away. You can save yourself some money by replacing the part yourself, but this is a job for an experienced DIYer and may take anywhere between four to six hours. Time to put those mechanical tinkering skills to the test!
Difficulty Level: Hard
Here's what you'll need:
- Wrench and socket set
- Torque wrench
- Razor blade
- Wire scrubber
- Clean rag
- Replacement camshaft
- New cover seal (this may come with your new camshaft)
- Lubricating fluid
- Personal protective equipment (safety gloves and glasses, closed-toe shoes, etc.)
- Vehicle owner manual
And here are the steps:
- Open the hood of your vehicle and use your wrench to disconnect the negative battery cable from the battery terminal.
- Remove the bolts that are keeping your air cleaner assembly in place and loosen the claps holding the intake pipe to the air box.
- Remove the entire air cleaner assembly.
- Locate the crankcase ventilation tubes and disconnect them from the camshaft cover.
- Remove any wires and brackets you may find on the camshaft cover. Use your socket wrench to remove any bolts.
- Use your socket wrench to remove the bolts securing the upper timing belt cover in place before removing the timing belt cover.
- Remove any crown nuts, grommets, and washers holding the camshaft cover in place. Don't lose any of them as you will use them again later.
- Lift the camshaft cover up and off the engine.
- Remove the gasket. If it has melded onto the cover and cylinder mating surfaces, use your razor blade and wire scrubber to remove the gasket material. Wipe the surfaces clean with the rag.
- Unbolt the distributor's mounting brackets and disconnect all electrical connections. Remove the distributor.
- Loosen the valve adjustment lock nuts until they no longer hold the valves open.
- Carefully loosen the rocker arm shaft pedestal bolts by turning counterclockwise in 1/4 turns. Follow a crisscross pattern with each bolt. When the bolts are loose enough, lift the rocker assembly out of the engine.
- You can now lift the camshaft out of the engine.
- Apply lubricating fluid to the camshaft, the camshaft bearings, and the valve lifters.
- Install the new camshaft. Make sure the timing marks of the camshaft and crankshaft gears are aligned.
- Return the rocker assembly and camshaft cover (use a new one if provided). Use your torque wrench to tighten all the bolts according to the torque specifications provided by your vehicle owner manual.
- Put everything back together by following the reverse order of disassembly.