S54 Valve lash findings

[longress]

I checked the lash on my Z4M this weekend to find that the majority of the valves had tightened up. I have no idea if the valves had been adjust previously as I purchased the car with 40,000 miles on the engine (the car is currently at 44,000).

What has everyone else found when checking valve clearance? Most valves were only a thousandth or 2 out of of spec or on the tight side of the spec. My motorcycles with the aluminum heads tend to get tighter too, from what I understand this is a result of the valve seat recessing slightly into the head.

Those that have done multiple adjustments on the same engine what has been your findings?

[yousefnjr]

Looking at the measurements for my last 3 adjustments (over 20k miles, I spoil her I guess..), I see them go both ways like you do. They've only ever changed by 1 thou in either direction. Could be what you say about seating, could be different temps (cold in April is different than cold in December maybe), maybe fine particles in the oil, I have no idea. Wouldn't worry about it if they're all in spec though.

[inTgr8r]

i haven't seen anything (posted) that would point to an identifiable trend re. adjustments.

I'll be doing my 2nd adj. this spring and will see if there's a trend.

[jmillet]

Two DIY valve adjustment results at Insp I and Insp II.
S54 VALVE ADJ Insp II 10-09-2012.pdf
S54 VALVE ADJ Insp I.pdf

[Jumbosock]

I've also done two DIY valve adjustments and have not found any that are too tight, although I've heard of that happened on rare occasions. Did you let the engine sit over night before doing the adjustment? The engine should be absolutely cold when measuring.

[longress]

Yes, the car is down for the winter so it is in my garage which is kept at about 60 degrees.


Jmillet - I noticed on your report that you used some different size shims. Did you get these in a kit or order them individually? I ordered the ECS kit and the shims are every .04 mm.

I made about 10 shim changes and found that I kept using the same size shims so I need to reorder a couple sizes as there is only 3 or 4 shims in the kit at each size.

[inTgr8r]

^that's the problem with that kit.
I have a list of the min max sizes needed that I'll post when home.
also the right feeler gauges are critical to proper size testing

[longress]

Definitely! I have several sets of feeler gauges and the set that came in the kit was not going to cut it as you need some length and some angle to get between the rocker and the shim correctly. Valve 1 is really tight with the head structure blocking the access a bit.

[StickMon]

This is what I use. Works great.

[longress]

^
Yep those are it. I had some long straight gauges that I bent an angle into them.

[jmillet]

Originally Posted by longress

Yes, the car is down for the winter so it is in my garage which is kept at about 60 degrees.


Jmillet - I noticed on your report that you used some different size shims. Did you get these in a kit or order them individually? I ordered the ECS kit and the shims are every .04 mm.

I borrowed a BMW shim kit that contained some used shims which explains the non-standard sizes. I now have the WISECO VSK4 kit ($45.95 from Amazon) which is similar to the ECS kit.

[Beedub]

i had one INLET tighten up so much i had to depress the valve spring to get the shim out!!!!
this was WITHIN the inspection time and the car had done sub 12k miles...

i Removed the shim myself , and got it back within spec , I've been monitoring yearly to see if their is a problem with that valve seat etc.... i do use the car hard and its very low miles maybe it had alittle more movement than expected, the car is also highly tuned ...

the engine inside was literally like brand new.... only the next few checks will tell the story if theirs something wrong happening on that valve. i actually posted about it on here, brought the tools from ECS and did this at home on my own, that was the first time I'd done the VC, now I'm REALLy comfortable doing it.

i no my car very very well owning it from new and it ran perfectly well not even a hint of an issue.... if it was for me over servicing the vehicle and doing all these checks early i could have easily ran the engine into the 20k miles before doing the inspection 2 and I'm not sure what damage this would cause to the engine. The valve wasn't being held open as i did a compression check. just a total anomaly ! You will find the video below very interesting, just look at the internals of the engine and note his comments to the condition. This car has been massively over serviced all its life.

[wspohn]

Clearances almost always close down with use as the valves sink further into the head/valve seat. I run 0.010" EX and 0.08" IN on a Cosworth L1 cam profile on an old English DOHC race car and need to check the clearance quite often to make sure they don't close down too much.

The issue of seat erosion is worse on cast iron head engines that with alloy head engines which by necessity have hard seat inserts that wear better. Som old cast iron heads had seats cut directly in the head material rather than using inserts and with the loss of lead in fuel, seat recession on cars used for high speed highway use can be pretty serious.

The situation on some alloy heads is such that frequent checks are in order. Jaguar 6 cylinder run .004 IN and .006 EX, so it doesn't take a lot for close them down, although once reset at maybe 20,000 miles, they seem to be able to go extended mileages without a problem.

What's the valve check mileage for the S54 - 60,000 miles?

[longress]

That's what I've seen on all of my motorcycles as well and I assumed this was probably the case. I wasn't concerned about anything wrong but since these shim kits do not always have the "perfect size" shim that you need to nail the preferred setting (middle spec) my intentions were to error on the side of how the lash changes with miles.

[wspohn]

You can go a thou and a bit wide, and it will wear in over time but don't vary on the tight side or you'll be in there again before you needed to.