Posted: Tue Jan 05, 2010 10:29 pm
HI all I think this is Charles's post from a while back I saved it to my hard drive.
If everything has been renewed & properly lapped into their seats with the tappet screws faced flat, .010" intake & .013" exhaust is a good COLD set up. The actual hot setting you need is .009" intake - .011" exhaust, the cold settings will tighten to the proper hot setting as the engine warms to normal temp due to heat expansion. These cold settings are also good for use in engines that have been run many miles & simply need a valve clearance adjustment when performing normal maintenance. If the tappet screws have not been faced flat, you will need to set up COLD at least .001" tighter on both intake & exhaust. The reason for this is it is normal for the face of the tappet screws to indent slightly, this is normal wear. When this happens a ridge around the outer edge of the screw face where the valve stem never hits becomes very evident. When adjustments are measured with a feeler gauge, it is on top of that ridge instead of where the valve stem actually contacts the screw face, thus the adjustment will be wider than the feeler gauge says because of the indent. In engines with a LOT of wear or indent in the screw surface, it may be necessary to bring the COLD adjustment as tight as .008" intake - 011" exhaust, but in most cases only .001" tighter will take care of it & produce a good running non-ticking set up. Remember these guidelines are for engines that are in good condition as far as the valve train is concerned. Ticking can also come from worn tappet bores in the block which allow the tappets to be pushed side ways slightly instead of straight up by the cam lobes. This condition will also produce a ticking noise that can be mistaken for loose valve clearance adjustment. If an engine has excssive wear in the tappet bores, the ticking noise will continue no matter what the adjustment. Also remember that a too tight adjustment can cause leaking valves & eventually burned valves. When your engine is started after adjustments are completed, it should be warmed up to normal operating temp. If all looks & sounds OK you should be set, go ahead with closing everything up. If you feel further fine adjustment is needed, let the engine COOL DOWN THOROUGHLY before readjusting, always remember you are working with COLD settings.
If everything has been renewed & properly lapped into their seats with the tappet screws faced flat, .010" intake & .013" exhaust is a good COLD set up. The actual hot setting you need is .009" intake - .011" exhaust, the cold settings will tighten to the proper hot setting as the engine warms to normal temp due to heat expansion. These cold settings are also good for use in engines that have been run many miles & simply need a valve clearance adjustment when performing normal maintenance. If the tappet screws have not been faced flat, you will need to set up COLD at least .001" tighter on both intake & exhaust. The reason for this is it is normal for the face of the tappet screws to indent slightly, this is normal wear. When this happens a ridge around the outer edge of the screw face where the valve stem never hits becomes very evident. When adjustments are measured with a feeler gauge, it is on top of that ridge instead of where the valve stem actually contacts the screw face, thus the adjustment will be wider than the feeler gauge says because of the indent. In engines with a LOT of wear or indent in the screw surface, it may be necessary to bring the COLD adjustment as tight as .008" intake - 011" exhaust, but in most cases only .001" tighter will take care of it & produce a good running non-ticking set up. Remember these guidelines are for engines that are in good condition as far as the valve train is concerned. Ticking can also come from worn tappet bores in the block which allow the tappets to be pushed side ways slightly instead of straight up by the cam lobes. This condition will also produce a ticking noise that can be mistaken for loose valve clearance adjustment. If an engine has excssive wear in the tappet bores, the ticking noise will continue no matter what the adjustment. Also remember that a too tight adjustment can cause leaking valves & eventually burned valves. When your engine is started after adjustments are completed, it should be warmed up to normal operating temp. If all looks & sounds OK you should be set, go ahead with closing everything up. If you feel further fine adjustment is needed, let the engine COOL DOWN THOROUGHLY before readjusting, always remember you are working with COLD settings.