Rocker arm rebuild question?

[tom.langborg]

Hi
My engine has overrev and three rocker arms are broken.
Should i only replace the three or should i replace all?
Is there some thing more i should check or replace.
Is valvet adjustment screw included in a new rocker arm or could i use the old ones.

Regards
tom

[burgermeister]

You may want to replace the connecting rod bolts, esp. if you have a 3.2 - they may have stretched. Also check for bent valves.

[tom.langborg]

Thanks
I have 3.0 SC so my rod bolt are stronger so i don't think i need replace this.
But i am worry about the other rocker arms.
Is a close visual inspection sufficient.?
Looking for bent valves is also included.

/tom

[KTL]

Obviously check your valves, valve guides, springs, pistons, cylinders, rods and crank. The valves contacting the pistons is what broke the rocker arms. Pistons are connected to the rods, rods connected to crank. All that force to break the rocker arms was transferred through those components. When the pistons hit the valves, the piston is cocked in the cylinder bore through the valve contact

[Walt Fricke]

Tom

I wouldn't worry about the other rockers - they stood the test.

What I'd worry about is the valves where the rockers broke. For that matter, all of your exhaust valves.

Use your leakdown tester for this. If you don't have one, buy one (under $100, very useful tool). Or borrow one, or visit a friend who has one (and an air compressor, which is what you need to do the leakdown). Failing that, have a shop do the leakdown.

While the leakage numbers are important (you see a 30 percent leakage in one cylinder, and 6-8 in others, you know where you have a problem). But equally as diagnostic is to listen to where the air is leaking out. Some always can be heard through the engine breather hose (disconnect this from the oil tank so you can listen), because some always gets by the rings. But you should not hear more air escaping from the tailpipe. Or from the airbox (pull the air filter, lift the air metering plate, and open the throttle to get a good listening path) if an intake is bent.

If the leakdowns are all reasonable (that's a whole different subject, but you are looking for variances, and where the leakage is coming from), you may have dodged a bullet.

I ran a 2.7 for over a year with badly bent exhaust valves. They reseated themselves by sawing a slot in the valve guides. Didn't help the power much, though the car wasn't a dog that way. The risks are that delaying repairs for too long might result in valve breakage, which is catastrophic to the engine.

I have reused the elephant foot adjusters with no issues, although some recommend replacing them no matter what. You should inspect the narrow neck just above the swivel cups to see if it is bent. That's the most likely point of failure.

Walt