The Triumph Spitfire is a classic British sports car that requires regular tune ups and adjustments to maintain peak performance. Part of a comprehensive maintenance schedule includes routine valve adjustments every six months or 6,000 miles. A valve adjustment is a simple maintenance procedure well within the abilities of the average weekend mechanic. Spitfires are, by design, very easy to work on with the right information and a few simple tools.
Apply the parking brake, shift the car into neutral and chock the wheels.
Remove the spark plugs, valve cover and valve cover gasket.
Number the rocker arms and valves from #1 to #8, starting at the front of the engine.
Rotate the engine with a 1 13/16-inch socket and 3/4-inch breaker bar until the #1 valve is fully open and just starting to close. Adjust the #8 valve to .010 clearance with a 1/2-inch wrench and screwdriver.
Rotate the engine with the 1 13/16-inch socket and 3/4-inch breaker bar until the #2 valve is fully open and just starting to close. Adjust the #7 valve to .010 clearance.
Adjust the valves from front to rear using the "rule of nines." The "rule of nines" is: 9 - (# of the valve fully compressed) = the # of the valve to adjust. For example, when valve #3 is in position, it is time to adjust valve #6 (9 - 3 = 6).
Repeat Step 6 until all valves have been adjusted. Replace the spark plugs, valve cover and valve cover gasket.
Petroleum jelly can be used as a gasket compound so that you can reuse the valve cover gasket several times before replacing it. Use a fender cover or blanket to protect the car's finish when working on the engine.
Always rotate the engine clockwise. Rotating the motor counterclockwise will result in inaccurate valve adjustments.