Why do my posts fall on deaf ears?

VALVE LASH!

 

we don't? probably not the ideal thread for you to reply in - you can give the $900 to me

To the OP, as Jetpilot said, it is probably a lifter (or lifters) that are now out of spec, or worn. Is the noise new, or has it always been there since you did the cams? Over the course of time with more aggressive cams, more maintenance will be required. I would recommend taking the valvecovers off, and having an experienced mechanic check the valve lash first and foremost, and inspect the lifters for any signs of damage.

 

Adam:

Our buckets (lifters, tappets, I don't know...) are hydraulic? I didn't think you shimmed hydraulic lifters?

whenever I see 'lifters' I think pushrods

 

+1 we have buckets,we dont "lift" anything.....we push.o.e. buckets come in different thickness to adjust for lash,but if your ticking started recently you might have a carbon problem,as worn valve seats would actually tighten the lash.

 

to the OP - this is from the factory service manual

CAMSHAFT
EM-75



1. Remove camshaft.
2. Remove the valve lifters at the locations that are outside the standard.
3. Measure the center thickness of the removed valve lifters with a
micrometer.
4. Use the equation below to calculate valve lifter thickness for replacement.
Valve lifter thickness calculation:
Thickness of replacement valve lifter = t1+ ( C1 - C2 )
t1 = Thickness of removed valve lifter
C1 = Measured valve clearance
C2= Standard valve clearance:
Thickness of a new valve lifter can be identified by stamp
marks on the reverse side (inside the cylinder).
Stamp mark 788U or 788R indicates 7.88 mm (0.3102 in) in
thickness.
NOTE:
2 types of stamp marks are used for parallel setting and for manufacturer
identification.
Available thickness of valve lifter: 27 sizes with range 7.88 to 8.40 mm (0.3102 to 0.3307 in) in steps of 0.02
mm (0.0008 in) (when manufactured at factory).
5. Install the selected valve lifter.
6. Install camshaft.
7. Manually turn crankshaft pulley a few turns.
8. Check that valve clearances for cold engine are within specifications by referring to the specified values.
9. After completing the repair, check valve clearances again with the specifications for warmed engine. Make
sure the values are within specifications.
Valve clearance:
Unit: mm (in)
*: Approximately 80°C (176°F)
KBIA0057E
Intake : 0.30 mm (0.012 in)
Exhaust : 0.33 mm (0.013 in)
KBIA0119E
Cold Hot * (reference data)
Intake 0.26 - 0.34 (0.010 - 0.013) 0.304 - 0.416 (0.012 - 0.016)
Exhaust 0.29 - 0.37 (0.011 - 0.015) 0.308 - 0.432 (0.012 - 0.016)

 

i.e. we do not have hydraulic lifters. I was unaware anyone made billet buckets for the VQ though, that is cool.

so you either measure and order the exact size you need or you can shave down the little protruding point on the inside-bottom to set lash as well if it's tight, correct?

 

The SuperTech lifter upgrade is two parts. The first part is the billet lifter/bucket and the second part is a small precision machined shim of varying thicknesses that is placed on the back of the bucket. The lash is adjusted by changing out those shims.

On an OEM lifter setup, to adjust the lash, you simply swap in different thicknesses of lifters. They come in a couple dozen thicknesses.

From what it's worth, with JWT camshafts, we have never had to adjust lash...it always checks out within spec. I can't say the same thing for other camshaft manufacturers.

 

I can assure you the Z has lifers, I have a nice invoice from Nissan regarding this! The lifters making a really annoying ticking noise when they get bad.

 

hahaha, ok ok call them whatever you want I knew them to be buckets.

Our buckets don't act as I understand a lifter to function is why I don't call it a lifter. tappet maybe? bueller?

 

I typical "lifter" has a rocker arm attached to it. That probably where the confusion stems from. The VQ35, obviously has no rocker arms, but does have a lifter/bucket.

 

Thanks for the insight Sharif (meant to say that to your last post also)

But for the sake of my insatiable curiosity, am I wrong that the generic part is called a tappet and then there are different kinds (lifters, bucket, etc)? or are lifter and tappet semantics.

 

You are correct!

 

The engineer you have been using has given you poor information. For a start your motor is a VQ not a VG.

The VQ motor has never been fitted with anything other than solid tappets.

As all of the available commerical aftermarket camshafts are ground to the OE base circle there will be only minor lash adjustments needed & as Sharif has pointed out the JWT units have never needed adjustment.

Never the less the lash should allways be checked when ever any camshafts are removed & replaced

 

is it possible this dude has a 300zx or something?

 

Wow… this thread has gone so many directions and lots of confusing info (some bad info).

1) The VQ does not have hydraulic lifters

2) The VQ has overhead cams which push the valves to open (not lift)

3) To push the valve open, the cam pushes buckets/tappets (sometimes called lifters, even though they push not lift) here’s an example: http://www.google.com/imgres?imgurl=...&ct=image&cd=1

4) JWT cams don’t all have the same lash as OEM – the S2 for example use the same lash for the intake and exhaust cams – however, OEM specs are different on the exhaust side

To adjust valve lash, generally you use a different size bucket (different thickness)… if the mechanic measures the lash to OEM specs and your cams profile requires tighter lash, you may get valve tick.

It happened to me and seems like this might be the OP issue.

Here is a thread that addresses a similar issue (starts on post # 42) https://my350z.com/forum/na-builds/383566-cams-3.html

As for “solid lifters” = first define what the term is.

 

I had to change almost all the buckets for the Tomei 272's that I bought. Some were within spec though and some were way off....they make good power though.

 

did you have a bunch on hand? Or order the size you needed... if ordered, did your local dealer have them? The reason I ask is because some of my exhaust lash need adjusting and I have been told it could take a week to get the right size buckets after ordering (if the size needed isn’t on hand). I'm not thrilled about having the car sit a week waiting on a handful of $20 parts.

 

I had to buy them from a local dealer and they had to order them...they didn't have any in stock. They told me it would take a week and it actually took 4 weeks to get them all in...it took about 2 weeks to get just a few of those that I ordered and then the rest came another 2 weeks later.

 

not what I was hoping to hear/read... but thank you for the response... I'm forgoing for now - but the valve tick bugs me and I cant help but be miffed knowing the valve is opening later than it should (even if just nano seconds) I might bite the bullet and just do it (peace of mind at least - even though a pricey one {labor})

 

last I checked, they "lift" the valve off the the valve seat. That's why NIssan calls them lifters. You are right though. normally, you would think of lifting as an upward motion. ..........but, the correct term is "lifter."