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.
5. Flat key $2 approx.
6. Flat screwdriver From $1.
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