What would happen if you over tighten the Rocker Bolts?

[Ttop34]

Fairly simple question which might even be the fix of my problem. Exactly what would happen to the valves, springs, lifters and everything as well as what would happen to how the car runs? Would it not let the intake open enough and make a car run lean at the top end? Would it make a car backfire at higher rpm's? Would it make the oil preasure drop to around 40psi while idling at 700rpms?

A little different subject, will the tightening procedure be any different if the springs stand a good 1/4" taller than the stock springs? Still tighten till there's no play in the rod and then 1/4 turn?

As you can guess, even after the walbro 255, something is still happening at the top end. I'm currently running Sea Foam though the tank and will change the fuel filter after that. By then I should have my own AutoTap and see what's going on with the computer.

[phoenix64]

Funny you should ask. My friend just finished assembling a 355. it started but would not stay running. Well after a few days, we took the valve covers off and took 2 turns out of each rocker nut, and it fixed the problem. With the rockers too tight the enine can't compress the air fuel mix, b/c the valves hang open just a tiny bit.

In short, I don't think that it could be your problem.

[ January 10, 2003: Message edited by: phoenix64 ]</p>

[Ttop34]

Ok, I don't really get it. On my rockers, there's a bolt that goes through a pivot which is attached to the rocker arm. The pushrods don't twist or move once the bolt is finger tight. I really don't see them pressing much at all on either the Springs or the Pushrods since the Pivot is pressing against a piece that holds it up. Over tightening that would only press more against that piece right?

So should I just get them really tight or just finger tight and plus 1/4 turn?

[chazz]

You guys are talking about two different engines.

the chevy engines have adjustable rocker arms.

the 3.8L V6 engine has non-adjustable rocker arms.

so to answer your question,over tightening the rocker bolts on the 3.8L V6 won't hurt anything(assuming that you don't over tighten the bolts to the point that you strip out the threads or break the bolts!!!)also, you should always replace
the rocker bolts on the 3.8L engine with new ones
from the dealer or they might vibrate loose(new rocker bolts have a coating on the threads that prevents them from coming loose!!)

[Ttop34]

So do the rocker arm bolts have a torque spec? I've been told the LS1's are about 22ft.lb. From what I can tell, we have basically the same design.

[chazz]

My Haynes repair manual says:

rocker arm pivot bolts:

step one....132 in-lbs

step two....turn an additional 90-degrees.

this doesn't make much sense to me so you might want to ask at the chevy dealer!

[pgriffith]

<blockquote>quote:</font><hr>Originally posted by chazz:
My Haynes repair manual says:

rocker arm pivot bolts:

step one....132 in-lbs

step two....turn an additional 90-degrees.

this doesn't make much sense to me so you might want to ask at the chevy dealer!<hr></blockquote>

Makes plenty sense. First step, tighten to 132 inch pounds. After doing that turn bolt an additional 90 degrees. You need a Torque angle Guage to measure exactly 90 degrees.