Valve Lash

By Mike Palermo Jr.

For the most consistent results, start with a cold engine. Remove the distributor cap and turn the engine over until the rotor is pointing at cyl. #1 with the TDC mark on the pulley straight up and in line with the split in the case. Now, using the desired thickness feeler gauge, set both intake and exhaust valve clearances. Check while lightly pulling back on the adjustor screw, and then make sure that adjustor nuts are good and tight (approx. 16 ft.lbs.). Next, rotate the pulley backwards (counter-clockwise) 1/2 turn, and do the same on cyl. #2. Another 1/2 turn backwards for #3, and once again for #4.

Dyno testing has proven conclusively that if you wish to move the power curve lower (for a short track), setting all the valves at .007" clearance will do so. For the long straights, you want .003"-.004" clearance instead.

Now, it is very important to seal the valve cover properly. If not done so, you risk being black flagged for smoking, or losing the engine to oil loss, especially after a hard down shift or a high-RPM lift creates a vacuum and pulls the gasket inward from between the sealing surfaces. For this reason, I prefer the later style valve covers that come with a dimple that helps keep the gasket from dropping from the top of the cover. Make sure that the cover is clean from all oil and particles, and then lay a bead of Permatex Ultra Copper (preferred) or high-temp on the gasket surface of the cover. After seating the gasket, lay another even bead on it. You now have the option of either gluing the cover/gasket to the head, or placing it there after applying some form of release agent to the head surface, enabling you to re-use the covers several times prior to replacing the gaskets. I personally prefer redoing them each time as I feel that gaskets are very cheap compared to short races or thrashed engines. After installing cover, tamp it down lightly, sliding it as low as it will ride on the head for the best seal.

Good racing!

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