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Overview

Valve adjustment (.006")

Model years: 1965, 1966, 1967, 1968, 1969, 1970, 1971, 1972, 1973, 1974, 1975, 1976, 1977, 1978, 1979

Model: Volkswagen Beetle / Super Beetle convertible and sedan (also known as: VW Super Beetle, SuperBeetle, Bug, Type 1, Type I, Coccinelle, Vocho, Kaefer, Käfer)

Difficulty: 4 (1=adding air to the tires, 10=rebuilding the motor)

Time required: 30 minutes

Tools: 13mm box-end wrench (used to hold the lock-nut during adjustment) 19mm box-end wrench (or whatever fits your generator/alternator nut) large flat head screwdriver (used to pry bail from valve cover) medium flat head screwdriver (used in the actual adjustment) .006" feeler gauge Optional: floor jack 2 jack stands 2 drive-on car ramps

Parts: 2 cork valve cover gaskets (optional, but recommended)

Checking and adjusting the valves should be done every 3000 miles. Each valve must be opened and closed at exactly the correct moment as the engine rotates. There is a spring on each valve which holds it closed, but the valve is pushed open to either allow gas/air mixture into the cylinder or to allow the combusted gas out. The movement of the valves with push-rods and rockers is illustrated here.

Adjusting the valves sets the amount of play in the rocker mechanism and is a key factor in the performance and life of the engine. The valves are cooled when they are closed by transfering heat to the cylinder head. In addition to affecting the flow of the gases and power stroke of the cylinder, a valve which is too tight will spend less time seated (i.e. cooling) and therefore run hotter. This can lead to valve stretching and breakage. A valve which breaks off inside a running engine will cause extensive damage and require an engine rebuild.

Valves which are too loose will not open and close at the correct time, which adversely affects the performance of the engine.

Valve adjustment is about very small tolerances. Metal parts change size as their temperature changes. Therefore, it is imperative to adjust the valves only when the engine parts are all at exactly the same temperature (i.e. cold).

Applicability notes

This information in this article applies to Beeles with the following engines:

• "D" cased 1200cc (1965 in US)
• 1300cc (1966 in US)
• 1500cc (1967-1969 in US)
• Single-port 1600cc (1970 in US)
• Dual-port 1600cc (1970-1979 in US)

Contents 1 Overview 2 Applicability notes 3 Preparation 4 Step 1: Remove both valve covers. 5 Step 2: Remove the distributor cap. 6 Step 3: Rotate the engine clockwise until cylinder #1 is in firing position. 7 Step 4: Rotate the engine clockwise exactly 180° and verify that both valves on cylinder #4 are closed. 8 Step 5: Use the .006" feeler gauge blade to determine if the cylinder #4 exhaust valve is too tight or too loose. 9 Step 6: Reposition the adjustment screw as needed. 10 Step 7: Adjust the other valve (intake) on cylinder #4. 11 Step 8: Rotate the engine clockwise 180° to TDC and adjust the valves for cylinder #3. 12 Step 9: Rotate the engine clockwise another 180° and adjust the valves for cylinder #2. 13 Step 10: Rotate the engine clockwise another 180° to TDC and adjust the valves for cylinder #1. 14 Step 11: Verify your work. 15 Step 12: Clean the valve cover gasket surfaces and insert the new gaskets into the valve covers. 16 Step 13: Re-install the valve covers and secure the bails. 17 Cleanup / next steps 18 Related links 19 About this article

Preparation

• The engine must be completely cold (e.g. let it cool overnight).
• Know which cylinder is which.
• You must be able to position your engine exactly at top dead center (TDC) and 180° from (i.e. opposite) TDC. Read Top dead center for information about that.
  • The TDC mark (0°) will be used when adjusting cylinders #1 and #3.
  • The 180° mark will be used when adjusting cylinders #2 and #4.
  • The other engine angles discussed there are not relevant to this procedure.
• Although performing a valve adjustment can technically be done with the car on the ground, it's much easier if you give yourself some additional room. Putting the car on a lift is best. Using jack stands gives the next-best amount of room. In those methods, removing the rear wheels will give you even greater room to move, but isn't necessary. If those items aren't available, using drive-on car ramps will still be better than nothing.
• Don't be surprised if some oil drips out from the valve covers and cylinder head.
• You may wish to remove the .006" feeler gauge blade from the set. This makes it less unwieldy to work with. If you leave the gauge in the set, be careful to insert it to be perpendicular to the valve stem. A slight twist can cause the measurement to be off by a couple thousandths of an inch (which is relevant when the total clearance is only 0.006").

Step 1: Remove both valve covers.

Using a screwdriver to snap the bail downwards and free of the valve cover. Left-side valve cover (for cylinders #3 and #4) is located between the left-rear wheel and the muffler. The other valve cover is in the same place on the opposite side of the engine. To release the cover, use a large screwdriver to pry/snap the bail down. Under this valve cover is the cylinder head, rocker arm assembly, and four rocker arms.

Step 2: Remove the distributor cap.

Removing the distributor cap. Use the screwdriver to carefully pry off the two retaining clips which secure the distributor cap. Leave the wires connected, but move the distributor cap out of the way.

Step 3: Rotate the engine clockwise until cylinder #1 is in firing position.

Cylinder #1 is near its top when the distributor rotor is pointed at the mark on the distributor body. Using a wrench on the generator/alternator nut to rotate the engine by hand (via the generator/alternator belt). NOTE! Rotate the engine clockwise (the direction it runs). Rotating it backwards (counter-clockwise) introduces play in the various parts and leads to inaccuracy in valve adjustments as well as timing adjustments. If you need to turn the engine backwards, turn it at least 90 degrees back and then advance it to the desired position. Attach a wrench to the generator / alternator pulley nut. Rotate the wrench (and consequently the engine via the generator / alternator belt) clockwise until the distributor rotor points to the small notch on the edge of the distributor body. The mark on the distributor indicates where cylinder #1 fires, which is near the top of its stroke.

Step 4: Rotate the engine clockwise exactly 180° and verify that both valves on cylinder #4 are closed.

If both valves are not closed, they will be in different positions. Here the exhaust valve is open (i.e. pushed into the cylinder). 180° mark lined up with the crankcase split. From the point where the distributor rotor is pointing at the cylinder #1 notch, rotating the engine clockwise 180° puts cylinder #4 into firing position. Even though the engine was rotated 180°, you'll notice that the distributor rotor only moved 90°. The 180° mark on the crankshaft pulley should be lined up with the split in the crankcase. Look at the cylinder head on the left side of the car. The two rocker arms closest to the rear of the car control the two valves of cylinder #4. Verify that the valves are both closed (i.e. they should both be in the same position and should both have a tiny bit of play in them when you press on the rocker arm). Cylinder #4 is now ready for adjustment.

Step 5: Use the .006" feeler gauge blade to determine if the cylinder #4 exhaust valve is too tight or too loose.

When correctly adjusted, the feeler guage will fall when the rocker arm is pressed at the push-rod end. Feeler gauge inserted to check clearance between valve stem and rocker adjustment screw tip. This is cylinder #4's exhaust valve (left side of car). Start with the valve closest to the rear of the car (the exhaust valve). Slide the .006" feeler gauge blade in between the valve stem and rocker adjustment screw tip. The valve is too tight if the blade won't fit. It is too loose if the blade slides in easily with little or no friction. NOTE! The correct clearance is indicated when the feeler gauge blade will stay in place after tightening the lock-nut, but will fall down when you press on the rocker arm at the push-rod end (i.e. lower part of rocker arm).

Step 6: Reposition the adjustment screw as needed.

Box-end wrench and screwdriver used to reposition the adjustment screw. Hold the adjustment screw in place using the screwdriver, while loosening the lock-nut with the 13mm wrench 1/4 to 1/2 turn. Hold the lock-nut in place with the wrench while turning the adjustment screw with the screwdriver. Turn the screw clockwise to tighten the gap or counter-clockwise to loosen a tight valve. Check the clearance as described in Step 5. Once the clearance is correct, tighten the lock-nut with the box-end wrench while holding the screw in place with the screwdriver.

Step 7: Adjust the other valve (intake) on cylinder #4.

Move to the next valve towards the front of the car. That's the intake valve for cylinder #4. Adjust it in the same way as above.

Step 8: Rotate the engine clockwise 180° to TDC and adjust the valves for cylinder #3.

Feeler gauge inserted into the intake valve of cylinder #3 (left side of car). Verify that both valves for cylinder #3 are closed and repeat the steps above to adjust them.

Step 9: Rotate the engine clockwise another 180° and adjust the valves for cylinder #2.

Feeler gauge inserted into the intake valve of cylinder #2 (right side of car). The 180° mark should be aligned with the crankcase split. Verify that both valves for cylinder #2 are closed and repeat the steps above to adjust them.

Step 10: Rotate the engine clockwise another 180° to TDC and adjust the valves for cylinder #1.

Feeler gauge inserted into the exhast valve of cylinder #1 (right side of car). The TDC mark should be aligned with the crankcase split. Verify that both valves for cylinder #1 are closed and repeat the steps above to adjust them.

Step 11: Verify your work.

You may want to go around again to re-check and re-adjust until you are satisfied that the adjustments are correct.

NOTE! When you are finished with the last cylinder (#1), the exhaust valve on cylinder #2 (closest to the rear of the car) will be open. This is a sanity check that you ended in the right place and also allows some extra clearance for installing the valve cover.

Step 12: Clean the valve cover gasket surfaces and insert the new gaskets into the valve covers.

New gasket being inserted into valve cover. Ensure that both surfaces which touch the gasket (inside the valve cover and the surface of the cylinder head) are completely clean. It is recommended, but not mandatory to apply sealer to the gaskets. If sealer is used on the valve cover gaskets, it should be used only to fasten the gaskets to the cover and not between the gasket and the cylinder head. Discuss sealers for valve cover gaskets here. TIP! Replace the valve cover gaskets every time the valves are adjusted.

Step 13: Re-install the valve covers and secure the bails.

Re-installing the valve cover. Each bail should fit very snugly over the valve cover. If not, it is likely that the valve covers will leak oil when the engine is running.

Cleanup / next steps

Carefully lower the car.

Related links

• Nicely illustrated explanation of a four-stroke engine with similar layout to a VW Beetle
• Explanation of how valves function in a generic four-stroke engine

About this article