Knock Knock Revisited

[Schiada76]

I knew it was the oil that caused my problem! I pulled my motor and started tearing it down yesterday, pulled one valve cover then the next and there it was! A $@#@#^&&*%%$ rocker arm sitting there loose on the head. So I figure the Mobil One is so slick that it must have caused the poly lock to back off. It couldn't have been anything I did. Right? LOL :rolleyes:
Seriously though, what could I have done or what would cause this? Motor has about 8 to 10 hours on it since last tear down and the rockers and poly locks were brand new. Good thing I pulled the motor before finding this simple problem. I'll be changing heads and cam but I'd like to know if anyone has any input on what would cause this.
The really embarrassing thing is I fning knew it was probably a rocker but didn't check due to serious brain fart. :D

[slowpoke]

Too bad that you yanked the whole motor and found the rocker problem.
Mobil One is good oil after all.

[Schiada76]

Hey Slowpoke! First post ehh? You're no longer a virgin. How's the Beast coming?

[Infomaniac]

BradP:
I knew it was the oil that caused my problem! I pulled my motor and started tearing it down yesterday, pulled one valve cover then the next and there it was! A $@#@#^&&*%%$ rocker arm sitting there loose on the head. So I figure the Mobil One is so slick that it must have caused the poly lock to back off. It couldn't have been anything I did. Right? LOL :rolleyes:
Seriously though, what could I have done or what would cause this? Motor has about 8 to 10 hours on it since last tear down and the rockers and poly locks were brand new. Good thing I pulled the motor before finding this simple problem. I'll be changing heads and cam but I'd like to know if anyone has any input on what would cause this.
The really embarrassing thing is I fning knew it was probably a rocker but didn't check due to serious brain fart. :D It has screw in studs?

[KC]

AmsOil!

[Dave F]

I usually just torque my rocker studs to around 40#. Although the "loctite" thing is a good practice.
It sounds like a "shit happens" thing to me.
Sometimes there is just no other explanation :mad:
DAVE

[Schiada76]

Talked to a friend of mine who races and he said you need to set the nut to proper lash, tighten the poly and then crank the nut one more 1/4 to 1/2 turn to lock the poly down. Does this sound right? The stud was not loose by the way, just the rocker.
[ September 05, 2002, 07:58 AM: Message edited by: BradP ]

[Snowboat]

That sounds wrong to me. You set the lash with the nut, back up the nut so it won't move with a wrench, snug the allen screw up firmly, and then put your stud girdle on. The way he decribed will change your lash. A stud girdle is not much money and nothing will come loose.

[Schiada76]

Will a stud girdle clear valve covers that are beveled to clear headers?

[gnarley]

Sounds like who ever set the lash didn't tighten the poly locks enough, sorry JMHO :(
I have adjusted more of these than I care to remember & using a go-no-go feeler gauge I always started by setting a little loose then tighten the poly lock set screw then continued to tighten the adjusting nut itself until the lash felt correct. I've never... NEVER ever had one come loose or lost one. If you don't lock the set screw in by tightening the adjusting nut a bit more they can back off as the set screw does not have enough torque on it to hold the nut in place unless you put a girdle on it. And if you don't lock that set set screw in place they may come out! I remember helping a friend run his valves & found a set screw in the screen in a head! eek! It could of done major damage if it wasn't stopped by the screen. Needless to say he never snugged the set screws again, he tightened them :D

[78Eliminator]

BradP:
The really embarrassing thing is I fning knew it was probably a rocker but didn't check due to serious brain fart. :D Brad, did you use a torque wrench? If so, did you chase the threads of the studs/bolts with a tap/die? Has your torque wrench been calibrated lately? Any of those not being done could have contributed.....
Justin

[Schiada76]

The guy that set the lash would be me. :D
I didn't know about the " tighten set screw then a little bit more on the wrench method". Everyone I've talked to said that is the ONLY way to do it.
With an additional 1/8 to 1/4 turn MAX (leaning toward the 1/8 turn side. I was also told that a stud girdle needs to be set up properly or they can do more harm than good.
78E, The stud was fine the rocker arm came all the way off the stud. Although... Anyone know where to have my torque wrench calibrated in the San Fernando Valley?
Thanks for the replys! :D :D
[ September 06, 2002, 12:10 PM: Message edited by: BradP ]

[Infomaniac]

BradP:
Talked to a friend of mine who races and he said you need to set the nut to proper lash, tighten the poly and then crank the nut one more 1/4 to 1/2 turn to lock the poly down. Does this sound right? The stud was not loose by the way, just the rocker.I always give mine an extra bit of a turn after tightning the lock. I tighten the lock loose and tighten the nut the extra bit to get the proper adjustment. Always have.
The only disadvantage to this is it digs in to the top of the studs. wink

[Infomaniac]

BradP:
Will a stud girdle clear valve covers that are beveled to clear headers?I have IMCO beveled covers with crane gold rockers and stud girdles.

[502procharger]

i know this sounds stupid, but what does a stud griddle actualy due? should i have them put on my
new 540 i am having built? what are the disadvantages and advantages of them. sory to be the retard, i am pretty good with most bbc stuff, i just have had no exposure to a stud gridle

[GofastRacer]

The main purpose for a stud girdle is to keep the rocker arm studs from flexing and breaking from high lift cams, especially with aluminum heads!..I don't see any disadvantage to them at all!!..The best part I like is that you don't have to worry about the poly locks coming loose!...As far as clearance goes, usually any tall valve cover will work, at least all the ones I've used worked??.....

[Schiada76]

Well it turns out I am an idiot after all! Tore the motor down the rest of the way and found one spun main and the rest wiped. Can I blame the Mobil One again, or the guy driving the boat around with low oil pressure? :D
[ September 08, 2002, 01:50 PM: Message edited by: BradP ]

[gnarley]

BradP, after you heard noise did you ever pull your dipstick and look real carefully at your oil??? Remember how it looks after its been running for some time & it looks nice & clear? After you had low oil pressure & heard noise you should of been able to see suspended particulates of metal in the oil that looked like very fine glitter in paint! I have seen this every, & I mean EVERY time a bearing has spun. Sorry to hear of the damage but I doubt it really had anything to do with the Mobil-One it was more likely a clearance problem that was ready to say hello very soon anyway and the lower base viscosity was just enough to let it happen sooner. It must be those brand new rockers, ya want to sell them?

[Schiada76]

Gnarley,
Didn't check the oil I knew I was in for a tear down when I heard the knock, just thought I got lucky when I found the rocker. I'm not really blaming the oil it was shear stupidity on the drivers :D part, driving around with no oil pressure. Hey at least now I know what a spun bearing looks like and how to set the lash properly!