MrJeChou

Doing this job. It's going well so far except when bringing the fully assembled cylinder head back from the machine shop, some ******* cut me off, I had to brake hard and it rolled off the covered 2x4s I had it set on. I didn't want to place it down flat cuz a valve is sticking down. when I pulled over it was gasket face up resting on the spark plug tubes/camshaft journals. I'm visualizing the roll in my head and I see it tipping over onto the IM studs then landing right on the rocker arms and rolling into the position I found it in. I plan on doing a valve clearance adjustment but ****

Think tumble this did any damage?

ezone

I would have wrapped it in a blanket to protect it during transport.


My big concern would probably be that open valve getting bent.
I can handle fixing boogered threads on the studs if I needed to, but I have no idea if you can.

I'd suggest you take it back to the machine shop and tell them exactly what happened, have them look it over for damage.


Wrap it in a blanket or bubble wrap and box it up for the next ride.

MrJeChou

Hindsight is always 20/20.

The studs aren't damaged, and I don't think the valve got hit. I'm more concerned about it rolling off the studs onto the top part of the valve-train...

ezone

Ok, I think I can picture how it went now....




Check that it didn't smash any of the slots in the adjuster screws in the ends of the arms. Those slots are for your screwdriver to fit, you can probably tweak them a little by hand if you need to (and make sure you remember to adjust the valves upon reassembly).

The rocker arms themselves are pretty tough, but the open valve is not. I've seen an open valve get bent just setting the head flat on a workbench too hard.

HTH

MrJeChou

Good to hear. I think I'm going to risk it as I feel I've kept that valve safe. I just wish there was a way to check it without removing it from the head...

ezone

Easy. Just see if the valves leak.

Set the head upside down on the bench so the gasket surface is level.

Rotate the cam until all the valves are closed on that cylinder. Make sure all 4 rocker arms for that cylinder have clearance, that ensures none of the valves are slightly ajar.

Fill the combustion chamber with (gas, diesel, kerosene.....maybe even windshield washer fluid. Not water.)

Wait a while. (minutes to hours)

If no fluid leaks out of the ports, the valves are sealed well.
If lots of fluid leaks through, then the valves aren't sealed. Problem.

Confirm suspicion by repeating the test on a different cylinder and compare results.





Most machine shops do this leak check using vacuum.

MrJeChou

Doy! thought of this seconds after I posted. Wasn't sure what to fill them with though so thanks for that!

ezone

Plain water has too much surface tension to do a good test with IMO.
It doesn't want to seep through tiny spaces easily.

MrJeChou

I'm worried about the amount of seepage I'm getting from the exhaust valves (intake are all solid so far). I'm using Brakleen cuz its non-chlorinated and leaves no residue. Clearances look good but still worried about my valves...

How much seepage is tolerated?

ezone

Brake cleaner evaporates awfully fast.


How long did it take for it to leak?
How much did it leak?


Repeat your test on a known good cylinder. Compare results.


Which valve(s) were wide open when it rolled?

MrJeChou

Imma try gas tmrw


not long

hard to say, that's why I want to try gas. my finger was wet w/brakleen just from touching the underside of the head/combustion chamber around the valve and especially near the spark plug seconds after filling the port.


Haven't done them all yet. Not sure if i get consistent results if that means they are all good or all bad


One I haven't tested yet. I'm calling it a night and will have a better idea in the morn when I have all my results in.

Thanks for the help

BlueEM2

iTrader: (1)

Take it back to the machine shop and do another check on the head. Last thing you want is to put it back in and it's no good.

ezone

I do this check with the head upside down, level, and I fill the combustion chamber instead of the port.

But either way.

Are you positive that the valves you are checking are completely closed? There must be clearance between the tips of the rocker arms and the valve stems to ensure that the set you are testing are not being held slightly open by the camshaft.




How well did it run before you took the head off?


I did already suggest this. This is the best choice, they are supposed to know what they are doing at the machine shop.

MrJeChou

This is not going to happen.

For sure had clearance

Other than overheating (why I'm changing the HG) it seemed to run fine, although my mechanic expressed concerns about the overheating (not that they actually looked at it)...

After repeating my tests most of the valves leak pretty good, enough for me to NOT feel confident that it will work (or pass smog) when I put it back together. I do wish I had a better idea of how much seepage is tolerated, but the fact that some of them stay dry and some leak is not confidence inspiring.

Still confused though because I don't think the roll could have caused the poor results I'm getting, but I guess I could have bent them at some other time.

It did overheat like 5 times so that could have ruined my valves too.

Regardless my new Head Bolts don't come until Tuesday...

So should I order new valves too? Could the leaks be caused by something other then the valves being bent?

ezone

They probably aren't bent. The only one(s) I would have been concerned with bending was the one(s) that were open when it rolled. (assuming it ran good before it was disassembled and compression was ok)


Wear of the stem, guide, face and seat can let some amounts of leakage happen. Some might be forgiveable, but I'd say to let someone more experienced in that area decide if it is ok or not.

Take it back to the machine shop, have them see if it needs a valve job to correct the sealing problem.. (Wait, didn't they already check for this before they milled it?)

You didn't need head bolts for the job either, but that's ok..

BlueEM2

iTrader: (1)

If you aren't going to do the right thing then slap it in and hope for the best.

MrJeChou

Would a copper bristled brush work to clean the gasket surface of the block? Saw a video and it seemed to work pretty good...

ezone

I'd worry about stray bristles breaking off and going who-knows-where.



I use single edge razor blades.

It's only 'paint' on the surface, it should come right off.

BlueEM2

iTrader: (1)

To clean the surface gasket I used 1500 grit sandpaper. It's too soft to harm even aluminum but it does scrape the gasket off.

MrJeChou

What I went with. Takes some time but works great

MrJeChou

Finished, and it runs but not well.

The "Malfunction Indicator Light" is on, but I had the fuel cap off when I started it. It didn't go off when I tightened it down.

Smoke comes out of the exhaust manifold down where it connects to the pipe.

It wont idle. It did for a little really rough, and it runs if you give it gas, but it dies as soon as you take your foot off the pedal.

ezone

Recheck timing marks on the gears all line up right first thing!

MrJeChou

The timing belt is on correctly, finally got around to checking it...

ezone

Did you adjust the valves? Did you do this correctly? Do you have a service manual?

MrJeChou

Yes I have a manual, and I'm sure I adjusted the clearances correctly, although I do wish my feeler gauge had more sizes...

Anyway, I checked the timing marks again and now they don't look lined up. I guess I just had the wrong viewing angle, twice.

When the cam is at #1 TDC it looks like the crank is a tooth of the timing belt past #1 TDC. I know I can't rotate the crank over with the belt off because that would bring the pistons crashing into any open valves.

So can I rotate the crank backward a few degrees without damaging things? Or do I spin it around with the belt still on so the crank is at #1 TDC and then rotate the cam to where it needs to be?

Other wise how does one fix this without taking the head off again?

ezone

Doesn't your service manual cover this?
If you don't have the correct sizes of feeler gauges, then how can you be certain it's been done correctly?

Protip: Mirror and flashlight.

You can move the crank by a tooth in whatever direction it needs to go, as long as you know where the pistons are at and which valves are open..
(I personally would probably align the crankshaft to TDC position first, then move the cam into alignment, by the single tooth or whatever needs to be done.)

You must always know what positions all the pistons are in at any time when you do this, even though you cannot see them.

Never rotate the crank or cam while the timing belt is removed.
If the cam must be spun, each of the pistons all must be well below their respective TDC positions, far enough to allow room for all the valves to open through their complete cycle.

There are almost always some valves open somewhere in the head at any time. Pistons can/will mash whatever valves are open if you spin the crank through without the timing belt on it..

---

And if your timing belt was mis-timed, then that means your camshaft and valvetrain were also mistimed during the valve adjust, so you may want to double check valve clearances again too. With the correct size feeler gauges.
Just to be safe.
I prefer to run valves at the loose end of the spec range.

MrJeChou

Yes but the diagram doesn't quite capture the scope of the task...

The specs for the intake are .018-.022 mm and I'm using a .020 mm for them which is perfect, it's just the exhaust which are .023-.027 mm and the next size up I have from .020 mm is .028 mm. I made it so that the .028 mm fits in there, but pretty tightly.

Nice.

Good point.

We have them at the JC auto shop where I take classes, so I can adjust them to perfect there. I just need to get the car running well enough to get it the 45 miles up there without paying for another tow. I got smog due in Feb so I will probably re-do the valves before that.

ezone

I'd probably convert to a standard measurement, just because I have plenty of standard feeler gauges in my toolbox LOL.

.28mm is only about 0.011" so you would be pretty close with it.....and I like to run valves slightly on the loose side.
My theory: loose valves might be noisy, but tight valves burn!

MrJeChou

Whew, done. Car runs good.

It was the timing. So I spun the whole thing around until the crank was lined up, took the belt off, lined up the cam, then put the belt back on. Now to double check.

What???????? It's in the same spot I left it!

Around again, but this time about a tooth short of the mark on the crank, until the cam was lined up perfectly. Off with the belt again. Time to test my theory.

I put the belt on around in the order the manual said, used my wrench to move the auto-tensioner, slid the belt onto the cam sprocket, but this time as I released the tension on the belt my eyes were glued to the crank sprocket.

Sure enough as I released the crank spun just a tiny bit. When I looked it was just enough to line up the marks perfectly.

So this what what threw off my timing the last two times I but the belt on.

Anyway. Thanks to everyone for the help!

ezone