Useful Tips

Installing camshafts yourself


The camshaft controls the intake and exhaust valves of the internal combustion engine by adjusting the four strokes (intake, compression, power, and exhaust) of the ignition process. A camshaft is a sequential 1/2 turn of half the speed of the crankshaft, and all camshafts must be properly "timed" or serious engine damage can occur. Installing camshafts is an advanced engineering work, but you can learn how to complete the task as safely as possible for your product and model, and here are some general tips on how to complete the task correctly.

Reasons for removing and installing the camshaft on the engine

The reasons for removing or replacing the camshaft are actually not very many:

  • cylinder piston group replacement,
  • cylinder head repair,
  • when tuning the power unit,
  • camshaft malfunctions.

You can find out about the faulty camshaft by the characteristic dull knock when starting the engine. However, the appearance of a knock can speak not only about a malfunction of the camshaft, but also about malfunctions of other components and systems of the car. Among the malfunctions of the camshaft, it is worth noting the following:

  • wear, scratches or nicks on the support journals,
  • wear of camshaft seats in bed,
  • camshaft deformation or cracks.

What malfunctions is indicated by a knock on the camshaft

In some cases, when starting a cold engine, there is an extraneous thud in the valve cover. This is due to the fact that the “cold” ICE has no lubrication in the rubbing parts and after starting the engine oil begins to lubricate the rubbing parts, as a result of which the knock subsequently disappears.

The appearance of a knock is affected by:

  • malfunction of the camshaft bed,
  • deformation of the camshaft or its parts,
  • natural camshaft cam wear
  • malfunction of the lubrication system, including poor quality or untimely replacement of engine oil,
  • Incorrect fuel delivery.

Consequences of late camshaft replacement

Improper functioning of the camshaft leads to a loss of engine power, and subsequently to its premature failure, including as a result of jamming with poor lubrication.

If you did not fix the camshaft malfunction in time, then be prepared to repair or replace the valves of the cylinder head, premature wear of the exhaust system and its subsequent replacement.

Determine the need for camshaft replacement

The need for repair or replacement of the camshaft can be found out only after its troubleshooting, which is possible only with the camshaft removed and the presence of special tools.

Before taking the camshaft out of bed, you need to check it for axial displacement. To do this, lightly knock on the bed and if there is a knock, then, most likely, the camshaft is faulty.

In general, camshaft diagnostics can be performed without a special tool, visually. However, this method allows you to identify only visual defects (scratches, scratches, cracks, wear of the cams in the form of a "cut"), whereas

Using a micrometer, check the diameter of the support journals and supports of the camshaft housing. If the dimensions deviate from the permissible values, they can be repaired, but it is often easier to buy new parts, since restoration of repair dimensions is more expensive.

While access to the parts of the gas distribution mechanism is open (camshaft removed), be sure to inspect its other components: rocker arms, valve stem seals, springs and other details.

Necessary tools for work

In the process of removing and installing the camshaft, the following tools will be required:

  • keys (heads) in dimensions 7, 8, 10, 13, 17,
  • wrench
  • torque wrench
  • ratchet,
  • figured and impact flat screwdrivers,
  • hammer,
  • micrometer.

The procedure for replacing and installing a camshaft on the example of the "classic" of the Volga Automobile Plant

Replacing the camshaft with your own hands is not particularly difficult, but requires accuracy and care. If installed incorrectly, the cylinders will be out of order, which will immediately affect engine performance.

Camshaft replacement steps:

1. Removing engine attachments.

To remove the camshaft, first of all, it is worth removing the interfering attachments:

  • breather hose (weaken the clamp with a screwdriver and disconnect the hose from the air filter housing),
  • air filter with housing (unscrew 3 nuts on the cover of the air filter housing and 4 nuts securing the air filter housing to the carburetor),
  • suction cable (unscrewed with a screwdriver and key),
  • gas shutter drive (removed by disconnecting the drive and removing the lock washers).

So that nothing gets into the carburetor and then into the combustion chamber (for example, a nut, washer, etc.), cover it with a rag or plug the carburetor holes with it.

2. Removing the valve cover of the power unit.

Unscrew the 8 nuts securing the valve cover to the cylinder head, remove and rinse it.

When installing the valve cover, it is recommended to replace its gasket. This is due to the fact that after assembly, engine oil may be forced through it. When choosing a gasket, rubber-cortex should be preferred.

3. Removing the engine camshaft.

Before removing the camshaft, you must first combine the mark on the drive gear with the protrusion on the camshaft bed.

To remove the camshaft, you must first release its gear from the timing chain. For this:

  • using a key, weaken the chain tensioner,
  • bend the lock washer and unscrew the bolt with a key,
  • remove the chain from the gear, and so that it does not fall down, hang it (for example, on a wire),
  • in a checkerboard pattern from the edges to the center, unscrew the camshaft bed fixing nuts to the cylinder head,
  • remove the pastel with the camshaft assembly from the landing studs,
  • unscrew the two bolts holding the thrust flange at the end of the bed, and remove the flange,
  • we get the camshaft out of bed.

4. Troubleshooting camshaft engine.

Before buying a new camshaft, it is necessary to defect (see "Determine the need to replace the camshaft") removed, because it is possible that the engine did not malfunction.

5. Installing the camshaft and assembling the engine.

The camshaft is installed in the reverse order of removal. To avoid skewing when installing the camshaft bed, the bolts are tightened in the order specified by the manufacturer and with a certain effort (for the “classic” VAZ it is 18.3 N / m).

After replacing the camshaft, it is imperative to adjust the timing of the timing chain and adjust the valves; otherwise, you will have to repair them in the future.

After the work done, first inspect the engine and listen to its work, and in which case immediately repair the detected defects of the repair.