ok now seriously you probably aint gonna believe this, but i've got stock ratio (1.5-1) stamped steel rocker arms, all were brand new with my rebuild, and now after changing the cam and tuning the carb etc. I have thrown the rocker arm off the pushrod twice in the same day. a couple weeks after having changed the cam

what i know
after the first time i readjusted and ran it again, had all my power, but it seemed to be tapering off throughout the night, then it all together threw on a 6000rpm pull. and when it goes it feels like any other dead cylinder, up to that point it just slowly tapers off.

both times i checked the pushrod (stock length and size) for absolute straightness and it came out perfect.

the stud looks fine and has a slight knick in the upper part of the threads, but not where the rocker arm nut sits when adjusted, the valvetrain in the area is fine, and the compression test shows the valves are seating. (after readjusting the rocker arm of course)

turned it over a couple times and it seems the cam lobe hasnt been wiped, as it has almost the same lift as the rest, and i didnt give that idea much more thought, as i also followed the cam break in procedure by lunati to the t.

what i was wondering is what the possibility of the rocker arm nut backing itself off is, both times it threw the pushrod off the rocker arm nut looked about to fall off, immediately after adjustment i have my usual tire burning performance, then it slowly dwindles.

my issue is i've never heard or conceived of a rocker arm nut just backing off so i'm skeptical of my diagnosis, and i was wondering what you all thought

Thanks

 

It sounds as if a good set of polylocks might solve your problem. As for stock rocker arm nuts backing off? Pretty common occurance after the nut has been removed a few times.

c

 

if its a self aligning type rocker arm how are the tabs engaging the valve tip, were the valve tips ground when the engine was rebuilt? and like the other guy said after they've been used a time or two the lock nuts are shot, i make it a point to only use them one time and then trash em, they're cheap and its good insurance.

 

self aligning.... i think, whatever the one is that doesnt require rocker guide plates.

valves were brand new, with the heads and i told my machinist that i wanted em ready to bolt up, so I assume he did the checks and stuff since he had my combo, i'm not very head savvy so i figured have the pro set em up. this was just last fall when i went and got the heads, small machine shop so i had him do everything i didnt feel like doing/learning to do at the time, but the rocker arm lock nuts were removed twice for cam swap and maybe once for something else i cant remember... so new rocker arm nuts in order... should i get roller rocker arms right away too?

oh and anyone got some recommendations on a good company?

 

I will not run a self locking rocker arm nut because of that. I even put poly locks on stamped rockers. as for roller rocker arms I run scorpion roller rockers.

 

I'm with this guy it happens all the time

 

i'd go with some nice steel roller rockers if you can afford them. also run a stud girdle too if you have the extra $80. I believe the BTE one is around that price range

 

thanks all, saved me a lot of time tearing the motor down looking for issues that arent there, i'm gonna start my search for some low buck roller rockers and go from there.

thanks again, you're lifesavers