SilentBounty

I'm currently doing a head gasket job on my 3.0 and I got the heads off last night. I put them on a sawhorse and flipped them over to look at the bottom and all the valve buckets fell out! "No problem!" says I, and I put them all back over the valves and into a box.

Today I took the heads to the machine shop to get pressure tested and resurfaced if needed and mentioned this incident to the cylinder head guy. Apparently that was a big no-no! They said that it's a big deal if the valve buckets didn't go back in their original spot in the head. The motor may not even run!!

The guy was kinda really douchey about the whole deal. He acted like he thought I was stupid from the beginning and whenever I had a question he pretty much just cut me off and said he was just gonna do the heads for me. I feel like he was just not answering my questions because I am a very young looking 17 and he felt I wouldn't understand anyway. He didn't really tell me how I could fix this, just indirectly called me stupid for not knowing everything about a major engine component. That's why I brought it to you, because I DONT KNOW!

But anyways, how can I fix them when they come back to where they are in spec? All I got out of the guy was "You'll have to check the valve lash and get somebody else to do it who knows what they're doing." Okeydoke

Shady Cadence

Factory Service Manual, Valve Lash Adjustment.

Read that first.

SilentBounty

I'll give it a read, thank you!

millball

Consult the FSM to get an idea of whats what.

Have the valves and headwork done before proceeding because valve grinding will change the lash.

You should measure and record each pucks thickness, then assemble half of them into buckets and into one head and install the cam.

Got a good micrometer and feeler gauges??
I would recommend a set of go-no feelers like Proto #000N


Measure the lash of each valve with the cam lobe on its base circle and decide whether the lash is tight, loose or acceptable. Tolerances are a little different between intakes and exhausts, but there is considerable overlap.

Proceed by shuffeling pucks around until every valve has acceptable lash, or until it is apparent that you require some different new pucks, because the ones you have left cannot fulfill the tolerances. Intakes can be closer to minimum tolerance, but exhausts should be near maximum tolerance, especially #5 and #6 cyls.

Not really difficult if you are comfortable with mike and feeler gauge work, BUT.....

This is gonna be a long and tedious job, but somebodys got to do it.

It MUST be done right.

SilentBounty

Time isn't really an object and I love learning stuff like this! So pretty much I just measure the shims and put them into buckets to raise the bucket however high it should be? Could I just measure the clearance with a feeler gauge first the way they are, then measure the shims and mark all the info down so I knew which buckets needed which shims? Sorry if that's as clear as mud, I'm new ttovalves haha. I appreciate yalls help!

millball

Might give you a little headstart if the cams are already mounted.

scope103

When I had my heads machined, the valve adjustment was part of it. Much MUCH easier than doing it myself; the machine shop has the shim set right there and can just put in the right ones and be done with it. A do-it-yourself valve lash adjustment inevitably involves a bunch of shuffling, then off to ... somewhere .... to buy the new shims you need.

Of course, your relationship with this machine shop may preclude that approach.

millball

As obsessive compulsive as I am, I would never take anybodys word for the valve lash on a bucket and puck engine head, even a machinist I have known and trusted for years.
I would adjust them myself. In fact, I recently did.
On my 115,000 mi 3vz-e only 3 out of 12 lash measurements did'nt suit me and I had a friend cut the 3 thick pucks down with his precision surface grinder. I didn't have to buy any pucks.

Anybody who thinks these simple heads are a pain should try adjusting old Ducati Desmos.

SilentBounty

Idk I don't really need a valve grind job done because I can't afford it. Is it a service of a machine shop to only do the shims?

scope103

It's not "machining," it's just that my shop (at least) had the shim set. So you could always ask for a price, but it's not the first place I'd check.

Other than the shim set, doing it yourself is not difficult. Then when you find the ones you need, go to whoever has the set and buy them. (In my pre-headgasket case, my dealer doe==id NOT stock them, but they did have the two sizes I needed to buy.)

You will need a tool like this . (You can do it without the tool, but this is one that is worth having.)

If you're not grinding the valves (saving money is important, but once you have the heads off it may be false economy), it may be that your valves were already adjusted correctly. (unlikely) In that case, yours is just a sorting job to get the shims back in the right place.

KBAM

I'll speak to this. It would be much easier to outsource. When I did my lash it spanned over 2 days, probably 6 hours of work in total with a buddy and the FSM. I didn't have my shop do the lash because I wanted to learn on mine.

However, when I had the heads decked, I told him "to replace everything that needs to be replaced along the way." A fairly ambiguous statement in my book. The purpose was so I would only have to do the lash, not everything else. To my surprise he did not replace any of the valve stem seals when it was disassembled (I checked). I ended up doing that myself & I did the valves from scratch as well.

The point I'm trying to make, is even though you might think or assume the shop will do everything right, they might completely blow over something that's pretty damn important. Always check their work, no matter how reputable the shop is. That speaks to learning the task yourself, or at least how it "should" be done.

SilentBounty

Well you guys have convinced me to do it myself! A valve grind job was done on it right before I started working on it. My dad did that when he did the head gaskets on it. Surprisingly enough he neglected to check the heads or block for warpage and it blew back out pretty quick and now here I am with it. So that's my reasoning for not wanting a valve grind. I know the shims are right just not in the right order. I guess I'll give it a try when they come back from the shop. You guys help me so much so thanks! I'll probably have lots more questions though when the time comes!

SilentBounty

Here's an update for ya'll! I finally got the heads back yesterday after a prolonged wait at the machine shop's fault. That's a story for another time, though haha. But anyways, I put the cams and cam bearings back in the heads and started checking the clearances. Much to my surprise, they were all smack dab in between the specs for clearance! First try! And I know I didn't get a gimme from the shop because the guy told me he put them in there how I brought them. Well I made it all the way to the back driverside exhaust valve. Last one. After every single one being good, surely I wouldn't be this lucky, right? Nope. Way too tight. I can only clear it with a 0.003 and that was a little tight too! I swapped it out with a smaller shim, checked the clearances again, swapped one was good in its new home but the smaller one in the exhaust valve was still the same as the last! That can't be right. I flip the head over to look at the bottom and the valve looked almost orange. Burnt due to that stupid crossover. So my question now is this: New valve or smaller shim? It still opens and closes but I can't tell if its closing all the way. I thought a burnt one would make the clearance looser, not tighter? Thank you all for your wonderful help!

scope103

Other way around. The valve was burned BECAUSE it was too tight. Once the valve warms up and that .003 turns to negative clearance, it doesn't close all the way and the valve isn't cooled by the valve seat.

I doubt the cross-over had anything to do with; lots of us have stock exhausts without burning up valves.

millball

Squirt some WD-40, or something similar into the exhaust port and see if the closed valve will hold it. You can't judge the valve just by its color. Maybe its still OK.

SilentBounty

OK so just see if the valve holds it while it's closed? If it holds the WD 40 in there without leaking, then let's it out when opened the valves is good and that would be smaller shim? And I still don't like the look of that crossover. Seems like a bad idea to put four cylinders exhaust to one cylinders exhaust valve. Plus that's the only valve that looks charred orange. But I have no idea I just want to fix the valves hahaha

millball

Yes, if the valve will hold light liquid like WD-40 or kerosene when closed, it is still OK. (no seeping)

All it will need is a thinner shim to provide the proper valve lash.

SilentBounty

I'll check it when I get home and report back! Thank you!

millball

Any progress to report on this??

SilentBounty

Yep. I ground the shaft of the exhaust valve down to spec and now everything is where it needs to be. I have the drivers side head back on, the exhaust manifold, and the downpipe. I haven't had time to do any more to it. Unfortunatly I work 6 days a week plus going to High School so I haven't had much time for my poor yota I'll get her though! When I do you better believe I'll be reporting here!

P.S. The valve wasn't burnt, just ugly. It held WD-40 but just to be safe I performed a valve grind. Took a while with that stupid suction cup thing but I did them. Everything is still fine there!