I think #2 ate itself...., Who wants to guess my compression numbers... Options

[rick 918-S]

Your getting it. Steady in jerks.

[VaccaRabite]

UPDATE!

AND GOOD NEWS!

I pulled the head, and there was NO DAMAGE.

What happened: The screw that hold the #2 intake rocker backed off. This closed the intake valve (which is why I got no reading on the sync tool when the cylinder when dead).
Question. I torqued these down to the value in the Haynes manual, and one backed off after 5 minutes of run time. Should I run thread locker on these bolts, or did I just make an error on assembly?

I pulled the cylinder, and the rings look good, and the cylinder is not scored.

The head looks good to me, but I am far from a pro. I'll post up pics in a bit.

Is there anything I need to look for before I button it up and run it again? I ordered a rebuild kit from the alfa carb guy on Ebay, so I am not going to run it again till I get those suckers rebuild. But I am excited about my prospects.

Zach

[Gint]

That's pretty good news considering...

Waiting to hear responses on this question. I should re-check the torque on mine after installing push rod tube orings. I got it running again but it's a tad rough and I've got spark on all four. That's where I stopped. I'm beat.

[cwpeden]

I've seen stripped threads on valve screws, might want to check it out.

Sounds like your making good progress though. I had a comedy of errors putting my 73 together and it all came down to the Tach wire on the wrong terminal of the coil.

[Rick L]

You guys are making me weary about my rebuild. (IMG:style_emoticons/default/smile.gif)

Congrats, Zach...on the baby (and the motor)!

[Dr Evil]

Zach, are you SURE that the adjuster backed out, or did the stud that the rocker assembly attatches to start pulling out? It is a semi common failuer to have the studs come out and cause what you described - constant loosening of the vavle adjusters.

[VaccaRabite]

Eh, I had all of an hour last night to play with my car (not complaining - its more then I have had the entire week prior). I did not check the stud. Now that I know I should, I will go out and look at it after work.

So, I should not need to use thread locker on the stud then?

Is the correct washer the wavey washer (what was on there), or should I be using a lock washer?

Zach

[Dr Evil]

The wavy washer is correct. You do not need lock-tite, but see if the stud but can be tightened to torque again. That should be a clue. The adjusters should not come loose if you tightened the lock nuts correctly.

[VaccaRabite]

Lock nuts, you say. The nuts on it now are just standard nuts. I'll see if I can find some lock nuts for that size stud at HD after work. Any clue what the size and pitch is for those little guys? M6X?? sticks in my head, but I am unsure.

Zach

[type11969]

They are just thin jam nuts, when Mike said lock he just meant that they lock the threads of the adjuster to the rocker by tensioning the threads of the adjuster against the threads in the rocker. Using a nylock nut on there would make it a bitch to adjust. Check to see if the threads stripped out of the lock/jam nut too, I'd find it hard to believe that an adjuster would just come loose if the lock/jam was properly torqued.

-Chris

[type11969]

Well I suppose the adjuster is tensioned by the lock nut but the threads of the adjuster are compressing against the threads in the rocker but ehh, details.

[Dave_Darling]

It sounds like people are talking two different fasteners, here. One is the jam nut on the valve adjuster. The other is the nut on the stud that holds the rocker shaft onto the head.

I believe that the rocker shaft nuts are M7, one of few fasteners on the car that take an 11mm wrench. (If they take a 10, then they're M6.) I forget the pitch. The nuts are not self-locking fasteners, as far as I can tell.

Those should be torqued when the particular cylinder is at TDC and both rocker arms are slack. If you try torquing them with one valve open, the spring pressure won't even let the shaft seat against the head by the time you get to 10 lb-ft! (BTDT.)

--DD

[type11969]

Wow, thats good info, never thought of that and must have been lucky to have never run into that problem!

[VaccaRabite]

Those should be torqued when the particular cylinder is at TDC and both rocker arms are slack. If you try torquing them with one valve open, the spring pressure won't even let the shaft seat against the head by the time you get to 10 lb-ft!

AH-fuching-HAH.

Thansk for that tip, I had not picked that one up yet, and would explain my problem. I wonder if #4 is backing off too? I'll have to check tonight.

Zach

[Gint]

It sounds like people are talking two different fasteners, here. One is the jam nut on the valve adjuster. The other is the nut on the stud that holds the rocker shaft onto the head.

I believe that the rocker shaft nuts are M7, one of few fasteners on the car that take an 11mm wrench. (If they take a 10, then they're M6.) I forget the pitch. The nuts are not self-locking fasteners, as far as I can tell.

Those should be torqued when the particular cylinder is at TDC and both rocker arms are slack. If you try torquing them with one valve open, the spring pressure won't even let the shaft seat against the head by the time you get to 10 lb-ft! (BTDT.)

--DD

(IMG:style_emoticons/default/agree.gif)
And I can confirm that the rocker arm studs are indeed 7mm. (IMG:style_emoticons/default/wink.gif) BTDT just the week before least when I was trying to make a home made valve spring compressor.