Hi,

I did a valve adjustment and now I have to install the valve covers with cork gaskets and some gray rtv on the side of the valve covers.The factory manual indicates the torque but not the sequence of tightening the nuts.

What could be a correct sequence?
X-shaped ?
Horizontal parallel ( === ) ?
Vertical parallel ( | | ) ?

What would be the nut 1, 2, 3 and 4?

Bolt/nut 1 = Upper rear or lower rear or upper front or lower front ?


Engine: Stock 1986 305 TPI (Firebird Trans Am)
Valve covers with reinforcements under the nuts


Thanks in advance for any suggestion or comments.

Denis V.

 

There's no "sequence".

Tighten them down evenly, such that you don't bend the sheet metal. Like, use a screwdriver style of instrument, and tighten one bolt; then the next; then the next; then the last; then go back to the first, and tighten it again; then the 2nd; then the 3rd; then the last; then go back to the 1st; and so on. Eventually you'll get to a point where you can't really carnk down on it any further with your screwdriver-like handle. That's probably somewhere around 4 - 5 ft-lbs. Entirely enough really.

I don't like to use cork gaskets for valve covers. That's just boneheaded. Cork is a natural material; tree bark to be specific. What do you suppose would happen to reasonably small amounts of any tree parts (leaves, scraps of bark, paper, sawdust, etc.) that just happened to drop it into your engine as you were putting it together? What makes you think cork is gonna do anything any different? That's just STONE AGE. Get that GUARANTEED TO FAIL crap out of your situation.

Do you know what the ABSOLUTE HOTTEST spot on a Chevy small block is? I'll give you a clue: it's the head casting right near the 2 center exhaust ports (LOTS of exhaust, no coolant flow between them). LOOOOOOK at your valve cover: you'll see that the center of the leaky side, the place where they always leak, is RIGHT IMMEDIATELY ABOVE those 2 exhaust ports. Cork doesn't stand a chance.

Use Fel-Pro VS12869R (some kind of neoprene or the like, totally NOT a natural material) that won't dissolve in motor oil and/or turn to dust with the heat. The Moroso ones are even better. I use gorilla snot (NOT RTV) to hold them to the valve cover, then grease on the surface against the head. And of course, I straighten the valve cover flange out before installing them, and then some; I bend the area around the hole about 1/8" HIGHER than the major flat area between the bolts. VCs ALWAYS get destroyed by overtightening. Hell, THE FACTORY destroyed them; you could take apart a brand new motor back in the day, and if you LOOKED AT IT halfway carefully, you could see it was ALREADY destroyed, from day one.

If you leave cork in there, won't matter what torque or "sequence" you use, it won't last.

Do the job right ("sequence" is not part of that) and it'll be fine. EFFFF it up, like put cork in it and/or don't straighten the flanges back out, you'll have a FAIL on your hands.

 

O.K.,

Thanks for your complete reply.

 

I agree with the above post. The key to sealing the valve/rocker cover is the gasket material not the torque sequence. If you look at any modern engine, they don't use cork gaskets in any location.