Hello. I just got my heads back from the machinist(needed a valve job) and since the valve job I think may have minimized my valve lash, I decided to measure them, and they are all on the low side of FSM spec, or just below spec.
I printed out a chart on jim wolf website, and I set my target lashes for Intake =.012", and Exhaust = .013".
I have been getting readings on Intake averaging around 0.010" and averages on exhaust to be 0.011"...with various out of specs here and there. So am I ok with just leaving them alone at the minimal specs and just replacing the few bad ones? O should I go all out and order 24 new buckets? Here's a shot of a few measurements I took on the exhaust side:

And anyone have the good deals on these?

 

I assume you've looked at the underneath of the buckets - see that little nub sticking up in the middle? That's what actually establishes the valve lash. If you use a Dremel small grinding tool with a flat side you can grind down the nub - stem - a bit and that will increase the valve lash spacing. If you can set up a micrometer to measure the "before" height of the stem measured from the top of the lifter and get a reference height then you can measure progress as you grind down the stem.

Courtesy Nissan On-Line parts have good prices on the buckets of lifters.

 

thank you-Yes I tried grinding down a bucket. They have a mirror-like finish on those nubs and after grinding the nub it was all scratched up making me question the structural integrity of the nub, making it fail after a while, but it should be ok to to this?

 

I did it on my current engine - using a real fine rotary stone works good.

 

you did this with those DLC buckets?

 

Yup - I had to install two sets of Cosworth cams, 'cause the first set developed cracks in the front of the cams where the locator pins are installed. I figured out the technique, then my machinist came up with a grinding method that allowed a measurement while grinding. It was time-consuming, but DLC buckets are over $18 each - even from Courtesy Nissan. That adds up quick. I had to buy a few, but we swapped them around first, ground down the few that were too tight, then I purchased the rest. Maybe half a dozen...

 

ok I tried with one bucket-the new in-spec nub that I ground down seems a little uneven. As these push on the valves at a high rpm, don't they need to be ground perfectly square or is a bit of unevenness ok? I figured they need to be ground perfectly square to meet the top of the valve stem, right?

 

Yes - the flatter the cut, the better - less chance of the metal compressing a bit. You won't get them perfect unless you chuck the grinding wheel into a drill press and take the grinder straight down onto the nub - just a little bit, then check the height. This metal is very strong, so not much to go wrong. The DLC lifters coating( Diamond-Like-Coating) is only on the top, where the cam lobe wipes across. Use a good oil additive like Comp Cam engine break-in additive when starting up the engine and run it at 2K for 10 minutes or so, then check gaps again.

 

ok, but I'm just probably going to try to reuse the mirror-like stock ones. I measured up to one thousandth of difference after grinding it, so the nub has high and low surfaces...I used a drill press to grind it btw with a pink rotary grinding stone meant for a dremel. I'm going to keep at it. Thanks for all of your help bro I appreciate!!

 

Glad to help - you reminded me of how big of a pain in the azz it is to get valve lash set of these engines when doing cam changes. I've installed three different cam sets in two 3.5 engines, and it never gets easier. Sometimes I really miss rocker arms and pushrods...

 

Did you write you numbers down that are on the bottom of the "lifters"? If so you may be able to swap a few of them around to get them with in spec, that's what I did with my engine, and I still needed to order two from Nissan. Once you know what number lifters you have you will be able to figure out which p/n's you need. It time consuming but it is just simple math in the end.

 

after getting the heads back, they replaced some of the lifters, and the replacements didn't have the numbers of the mm heights. So I micd them. I suppose they figured that some of the original lifters were too far out of spec? so when I got the heads back they were for the most part in spec, though near the bottom measurements. There were about eight out of spec by about a thousandth or so. My garage is pretty cold, so maybe that played a role in the borderline measurements, and in the shop where I assume is temp-controlled, they were more in spec? Maybe I'll try some DLC ones... Anyways thanks!

 

Lifters? Do you mean the cup-shape followers? If so, I don't see numbers anywhere on mine.
Here's my problem hopefully someone can help. I got my crankshaft followers swapped and out of order. Can anyone tell me how to get them in order please? My 95 Maxima won't start. I was only getting 125 psi engine compression (min 143 psi to start). I took off the camkshaft, and the psi jumped to at least 165.