Re: Checking piston to valve clearance
I have an awesome checking method that I came up with over the years I spent as an automitive machinist/ engine builder. Nothing is more accurate than this. Much more effective than the clay. Note that this is only for piston to valve clearance and not the radial clearance. For the radial clearance, the clay is the best and really only effective method. Heres what you do:
Install the lightweight checking springs that you spoke about from Comp and a solid lifter or a modified hydraulic lifter like the other guys spoke about above. (I used to use 2.8 Ford rocker shaft springs, Im Cheap) now with those installed, adjust the rockers to zero lash. (If you are even attempting this, Ill assume you know what zero lash is) Rotate the engine 2 full revolutions to make sure there is no contact. Now take a pack of feeler gauges and stack up .080 worth and insert between the rocker arm and valve tip. Again rotate the engine. If you feel interference, STOP and subtract shims a little at a time until there is no contact. This will be you piston to valve clearance. If no contact between the valve and piston, continue to add feelers .020 at a shot until you feel the valve touch the piston as you rotate the engine.(you can also choose to stop here if you arent interested in knowing exactly what you have becasue if it turns freely with .080 installed, sufficent clearance is present. If you want to know exactly what you have, well then carry on) Once it touches, subtract feelers in very small incrememnts like .002 at a time rotating in between each change until you feel no contact. Once no contact is made, you have your piston to valve clearance. NOW THE DISCLAIMER. Be very very careful when rotating the engine around. You dont want to muscle the engine around and possibly bend a valve. Take it slow and you will end up with perfect results. Keep in mind that I used to do this with one piston installed in the engine and no rings on the piston while mocking up and blueprinting. It is just as effective with the engine assembled, just a little more care needs to be taken. Hope this helps. If I can answer any questions about anything engine related, feel free to pm. Always willing to lend a helping hand to a fellow SyTY owner. :tup:
