How to Adjust Car Valves (Part 3)

How to Adjust Car Valves (Part 3)

This post is a continuation of Part 2 on How to Adjust Car Valves. Lately, we have gone through the following:

– Role of car valves

– Step 1: Prepare your vehicle

– Step 2: Case 1: Check valve lash with an overhead camshaft

 – Step 2: Case 2: Check the valve clearance using a screw and lock nut system

We will now cover the final part with the remaining steps:

 – Step 3: Case 1: Adjust the valves with pads

 – Step 3: Case 2: Change the valves using screw and lock nut

 – Step 4: Reassemble the valve

Step 3: Case 1: Adjust the valves with pads

For each valve, proceed as follows:

– Find the nominal value (manufacturer’s value) for clearing the intake and exhaust valves in the technical journal.

Note: generally, the clearance is larger for exhaust valves.

– Remove the disc from the top of the valve tappet using a special tool. The tool presses the camshaft to depress the tappet and the valve.

Good to know: You can find this extraction tool at automotive OEMs or specialized websites on the Internet.

– Measure the thickness of the deposited pellet with a micrometer. With some manufacturers, the thickness is engraved on the pad.

– Calculate the thickness of the pad to be placed.

Example 1: either the manufacturer’s value set A = 0.20 mm, the set value set B = 0.35 mm, which is too large, and the thickness of the original pad C = 3.25 mm. D is the thickness to be calculated for the new pad. The operation to be carried out is D = C + (B – A). D = 3.25 + (0.35 – 0.20) = 3.40 mm. The new pad to reduce the play is, therefore, thicker.

Example 2: For the same values, but with an increased clearance B = 0.05 mm, which is then insufficient, the operation is D = 3.25 + (0.05 – 0.20) = 3.25 + (- 0.15) = 3.25 – 0.15 = 3.10 mm. The new pellet is therefore thinner.

– Position the new pellet on the plunger.

– Carry out the reverse operation for the rest.

Step 3: Case 2: Change the valves using screw and lock nut

For each of the valves, perform the following operations.

– Loosen the locknut

– Place the shim of the required thickness between the rocker arm and the valve stem.

– Move the adjusting screw to the limit of the blockage on the shim.

– Lock the lock nut and recheck the clearance.

Step 4: Reassemble the valve

– Replace the cylinder head cover gasket.

– Replace the cylinder head cover gasket and reinstall the cover.

– Clean off any traces of oil.

– Warm up the engine and check for abnormal noise.

Necessary: On older vehicles, especially those with gasoline carburetors, perform a carburetion tune-up, as the filling of the cylinders is modified by adjusting the valve clearance.

Remember, you will need the following equipment:

1. Flat key $2 approx.

2. Jack From $10.

3. Spark plug wedge set $5.

4. Micrometer.

5. Flat key $2 approx.

6. Flat screwdriver From $1.

Thank you for staying posted on our new blog posts. Hope the posts from Part 1 and Part 2 till here would be of any help to you. Should you wish to read on a particular automotive topic, please do not hesitate to write down your request in the section below, and we’ll try our best to cover the subject for you. Remember to leave your comments below and share these posts with your friends.

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