I have a 1990 5.0 that has a 302 bored to a 331 stroker. I have a rocker arm that has been torqued to specs but has backed off the rocker nut. The and stud are not striped out. I have been told to replace the spring because it was floating the arm and making it viberate off. If any one can help? Thank you

 

I would reset the rockers (MAKE SURE THE NUT IS LOCKED IN PLACE WITH THE ALLEN SCREW ON THE TOP) first and see if they hold. what kind of heads and springs. does not seem likely to me that bad springs would make the nuts back off if they were locked in place properly, most rockers will need adjustment after the first 2hrs or less.

 

wow that is some bore to make your 302 to a 331...lmao...sorry had to do it, you ment stroked... any ways i would go over each rocker and check them out. if one came loose then others may just be loose also. this can cause havoic on the motor.

 

yes it can! LMAO

 

I would reset the rockers (MAKE SURE THE NUT IS LOCKED IN PLACE WITH THE ALLEN SCREW ON THE TOP) first and see if they hold. what kind of heads and springs. does not seem likely to me that bad springs would make the nuts back off if they were locked in place properly, most rockers will need adjustment after the first 2hrs or less.


I have Air Flow research heads and trick flow roller rockers and springs. I have reset the rockers and the same one keeps backing off. The stud and nut are not striped.

 

kinda a dumb question.......... but i was just wondering what kind of damage comes when you are reving the motor to 6500 and the valves start floating, what can a floating valve cause? bent valve? just wonderin

 

Well a number of things may happen, yes a bent valve is one, as well as a blown engine. Over-revving an engine is not good, and you can hear when a valve floats, almost like the engine is being choked out.

 

wow that is some bore to make your 302 to a 331...lmao...sorry had to do it, you ment stroked... any ways i would go over each rocker and check them out. if one came loose then others may just be loose also. this can cause havoic on the motor.

Well actually it is a D.S.S 331 stroker shortblock. The rest of the rockers are fine. I have torqued this rocker to specs and as soon as I get heavy on the gas it loose and hits agains the valve cover. And thanks for all of your advice to who has responded to this.

 

sounds to me like the stud is pulling loose from the head if the threads on the stud and the nut are not stripped. remove the nut and rocker arm and look at the junction where the stud leaves the head and see if it's pulling out of the head. if so, carefully back the stud out and get the proper sized heli-coil insert for the aluminum head and install it then re-install the rocker stud. it's relatively easy to pull the threads out of aluminum heads so don't overtorque them ever and use some anti-seize compound on the threads too to prevent the threads from galling and getting stuck in the heads too. in a worse case scenario, you might have to tap out the hole one size larger and use a larger diameter stud and rocker arm on that one valve.