Adjusting Rockers

**92306gt** · 01-16-2011, 03:35 PM

This might be a stupid question to some of you but im curious to hear what you guys have to say. a friend of mine pulled the heads off his mustang to replace a valve that got bent when a spring broke. heres the question..does he need to readjust the rockers or can he just bolt the heads back on and all be fine? i told him i would readjust the rockers to be on the safe side but im curious if it would be ok

**Silverhatch** · 01-16-2011, 04:04 PM

He didn't pull the rockers off when the valve was replaced?!? If he didn't take a video of him trying to reinstall the heads with the rockers pressing on the pushrods. I say yes, you kinda have to. Its easy to do, assuming they are hydr. rollers.

**SK@StreetLethal** · 01-16-2011, 04:06 PM

Yes take them off and readajust them all. The spring pressures will affect the torque reading on the head bolts. It doesn't take very long at all to adjust valves.

**gmkillr** · 01-16-2011, 04:22 PM

Originally Posted by SK@StreetLethal

Yes take them off and readajust them all. The spring pressures will affect the torque reading on the head bolts. It doesn't take very long at all to adjust valves.

Valve Spring pressure affects the torque ratings of the head bolts?

**SK@StreetLethal** · 01-16-2011, 04:42 PM

I'm assuming he was trying to put the head on with the rockers and pushrods in place?

**Silverhatch** · 01-16-2011, 04:51 PM

If your saying he pulled the rocker nuts off and marked which ones went where, readjust them. Hydra-rollers are pretty forgiving, but they are cake to adjust and takes about half an hour.

**wick** · 01-16-2011, 04:48 PM

Originally Posted by gmkillr

Valve Spring pressure affects the torque ratings of the head bolts?

If leaving he rockers on and the pushrods all still inplace, yes, it will affect torque value while trying to torque down a set of heads with the valves pushing back up on the head.

**92306gt** · 01-16-2011, 04:51 PM

Originally Posted by wick

If leaving he rockers on and the pushrods all still inplace, yes, it will affect torque value while trying to torque down a set of heads with the valves pushing back up on the head.

he told me he took all the rockers off, torqued the heads down, then put the rockers back on exactly how they were

**gmkillr** · 01-16-2011, 04:53 PM

Originally Posted by wick

If leaving he rockers on and the pushrods all still inplace, yes, it will affect torque value while trying to torque down a set of heads with the valves pushing back up on the head.

Why would anyone do that?
That would be like trying to change the brakes on a car without taking the wheels off....

Its very easy to set rockers up......:)

**gmkillr** · 01-16-2011, 04:55 PM

Originally Posted by wick

torque down a set of heads with the valves pushing back up on the head.

I would also think that you would run the risk of bending the valves doing it like this. Ive never heard of it before......But I dont take redneck shortcuts either!

**92306gt** · 01-16-2011, 04:09 PM

Originally Posted by luxurysportscar

He didn't pull the rockers off when the valve was replaced?!? If he didn't take a video of him trying to reinstall the heads with the rockers pressing on the pushrods. I say yes. Its easy to do, assuming they are hydr. rollers.

he pulled the rockers off and put them back on exactly how they were. i think it may be ok but i i dont know for sure. i told him i would just readjust them and be done with it

**oldfox** · 01-17-2011, 06:37 PM

OH COME ON ,,,,,,,,
Can't any of you guys remember taking of a valve cover for the first time and thinking man,,,,,,,,"look at all that stuff" If you have never set a set of rockers it might
look and sound scary. We think it's a cake walk but look how many times we have done it. 92306GT tell your friend to get on line and come to this web sight sine up
and start asking questions. The folks here are friendly and helpful and they will walk him through it. If he's not on line go to the library and use their computer

**wick** · 01-17-2011, 08:07 PM

Originally Posted by 92306gt

Yep..he said he hates adjusting rockers. i told him i would stop up and help him but he said f it, im just bolting them back down...whatever

Originally Posted by oldfox

OH COME ON ,,,,,,,,
Can't any of you guys remember taking of a valve cover for the first time and thinking man,,,,,,,,"look at all that stuff" If you have never set a set of rockers it might
look and sound scary. We think it's a cake walk but look how many times we have done it. 92306GT tell your friend to get on line and come to this web sight sine up
and start asking questions. The folks here are friendly and helpful and they will walk him through it. If he's not on line go to the library and use their computer

Its not that he does not know how, he does not want or like doing them.

**oldfox** · 01-25-2011, 12:26 AM

Originally Posted by wick

Its not that he does not know how, he does not want or like doing them.

Oh I never thought of that. Most of us on here are sort of just
like the old school hot rodders. We like working on our rides and
enjoy tearing them down and tearing them up.

**Killercanary** · 01-17-2011, 10:28 PM

Although I would never do it, a pedestal mount rocker can be snugged down to ~20ft/lbs of torque without actually checking them as long as the valve being worked on is not going to be in the open position when the rocker is installed. If it is the open position the pressure from the spring will alter the torque spec. As long as it is not open it can snugged down without the worry of starting at zero lash. That is the only good thing about pedestal mount heads. Once you have the correct length pushrods setting the valves is a cake walk. Stud are a completely different animal though. I have setup valves more times than I can remember.

A good rule to remember is to set the exhaust valve when the intake just begins to close, and set the intake valve as soon as the exhaust begins to open. If you do this it will ensure that you are on the base circle every time and you won't have to rip it back apart to re-adjust. I have never rotated any of my engines counter clockwise and I have never had an issue. I only go clockwise as I do not want the balancer bolt to back out.