[mizhele]

hello ive removed the lash pad from the 5 cyl.exhaust valve rocker on my 71 240z..the pattern looks centered but if i look close it seems to have a dip or groove in the center of the wipe pattern...is this normal???? im thinking worn....im checking them bacause ive got alot of valve noise in some rockers , clearance is good checked it 3 times..and its only in the 5-6 cyl.valves i hear it the most with a stethascope type mechanics prob from on top of the valve cover...is there a easy way to check lash pads ?? ive check the archives saw somthing about inking the pads?? and wheres the best place to get new stock pads if i need them?? thankyou michele

 

[jerja]

After a time slight wear on the pads is normal.If the valve lash is set correctly it will compensate for the wear.Most likely the noise is not being caused by pad wear.

One thing that can happen which is rare: The outside diameter of the recessed area on the lash pad side that contacts the valve tip can start to contact the valve sprng retainer. This will cause a loud valve tapping sound and eventual failure where the valve will drop into the cylinder. I had this problem 29 years ago when my 71 had about 60,000 miles. Fortunately I corrected the problem before it dropped the valve. Some later lash pads do not have the recessed area.

 

[Jason k]

Well you have two choices.You can replace the lash pads if the wear patten bothers you,install new valve springs(a worn spring will cause noise)then reset the wipe pattern using bluing ink(this procedure is detailed in How to modify your Nissan OHC from hp motorsports, old book but you still might be able to find a copy)or you can live with the noise and invest your time and money building a L-28e with a P90a hydrolic head if the valve train noise truly bothers you.The loudest thing at idle with these is the injectors ticking.I don't mean to sound condisending but investing this much time and effort into a 30year old L-24 is not going to give you the same benfits as the same time invested in a new L-28(old hot rodders adage Always build the biggest motor you can afford).