TT350

Hi guys

I bought my son a 96 TA, the owner told
me that if I run it hard that the rocker studs
would back out of the heads.

So on the way home I put my foot in it and sure enough
1 rocker started making noise.

The motor had a few oil leaks so I pulled the motor and stripped it down to the short block and replaced every gasket and seal.

I pulled all the studs in the heads, cleaned the holes with
carb cleaner, cleaned the studs, blowed the holes out with shop air and put red Locktite on the studs and torqued them down.

My wife drove the car to town the other day and called me and said the car was shaking.

The motor had a dead miss on #3 CYL.
The intake stud had backed out and the push rod had come off the rocker.

The guy I bought it from said that it had been a problem
the whole time he owned the car.

All the heily coils are in good shape and all the studs
are in good shape.

This is not a hot rod, it is bone stock with all the cats
and stock muffler.

What can I do to keep this from happening?
Chris

duh

iTrader: (16)

are they screw in studs? It sounds as though they were done with the wrong size tap. I'd start doing some asking, since factory are pressed in studs. If you're pulling the pressed studs out, then look into getting screw-ins. Hopefully things will work out for you.

TT350

Press in studs on LT1 aluminum heads?
This car is bone stock with 90K on the clock.

I don’t think your familiar with the LT1’s

RamAir95TA

iTrader: (2)

They are screw-in studs on the aluminum heads, press-in on the iron.

Very odd that the stud keeps backing out. Also, you need to use thread sealant on the studs. You might want to look into picking up some ARP studs and seeing if that does the trick.

TT350

Nothing wrong with the stock studs.

On oil leaking in the runners... no sealant needed.

05HD

How are you setting the lash? Only time I have seen studs pulling out on stock cam small blocks is when the lash is set incorrectly.

RamAir95TA

iTrader: (2)

I beg to differ. The rocker stud extends into the intake runners. In order to prevent oil leaking down the stud, you need thread sealant.

355TurboLT1

iTrader: (11)

Sounds like you have it all figured out. Why even pose the question.....

05HD

Guys, if he wants to suck all his oil in thru the rocker stud threads, who cares?

He sounds like the guy I used to work next to at one of the dealerships, thought he could set valve lash with an impact gun and nobody could tell him different, even though every single one came back with 1 or more studs pulled out...

TT350

Look guys I’m no rooky.

When you have a stud that has a flange built
into the bottom of the hex and it seats flat on the stud boss it seals the stud to the hole it will not leak.

Now if you have slotted guide plates there will be a portion of the slot exposed and the oil will puddle in the slot under the head of the stud and it will be sucked thru the threads into the runner, sealant is need for these.

The lash is set to ½ turn past zero lash.

The stud is not being pulled out of the head.
It is working it self loose and un screwing it’s
self out of the head.

I’m not trying to be difficult, I’ve been around
SBC’s for a long time and this shouldn’t be happening
on a bone stock daily driver.

I’m posting in here to see if any one has run into this before.

Chris

RamAir95TA

iTrader: (2)

I understand that you've worked on SBCs for awhile, but the fact of the matter is GM recommends you put sealant on the threads. It's a very simple step. I don't know about you, but I'd feel better knowing the thread sealant (not an imperfect interference fit, like you think) is keeping the oil out of my intake runners. Your logic indicates that it's okay to not use thread sealant on, say, head bolts, or water pump bolts. Guideplates or not, sealant is required if you want it done right.

And honestly, if the stud keeps working its way loose, you're perfect interference fit isn't so perfect, is it?

JMHO.

TT350

So tell me why my stud are coming loose.

I didn't post asking why is my motor smocking,
now did I?

RamAir95TA

iTrader: (2)

Perhaps it's because oil is leaking into the threads.

Doughboy692

This thread got me to thinking I might be crazy so I went out to the shop and pulled some rocker studs. I have 4 sets of LT1 heads that are Bone stock they are all off of 95 Model Year Camaros and Firebirds. I pulled several rocker studs out and NONE of them go into the port on either the intake or exhaust. So if you guys have a 95 MY LT1 that is sucking oil into the intake port through the rocker stud threads you might want to check and see if there is a bigger issue at hand (like a cracked head in the intake port very unlikely but if your sucking oil there must me somthing amiss)

Now to the OP question.
If the studs were put in too tight or somwhere along the line somebody got a little to aggresive with a tap cleaning the threads they may be worn and allowing the stud to rock a little. If this is whats happening you can put all the locktite in the world on them and they will eventually come loose.

I would start with a brand new set of rocker studs I use ARP and they have never let me down. If that does not take care of it you are going to have to either replace the heli coils or replace the heads all together.
Take care
Rob

Wooshie

Exactly what I was thinking.

RamAir95TA

iTrader: (2)

I am going to stand corrected.

The rocker stud hole is only a problem on cleaned-up or ported heads, where the rocker stud hole is easily seen. On stock castings though it is rare. Either way, you don't want oil leaking into the rocker stud. Thread engagement is fairly minimal (only about 8 threads of engagement) and adding lubricant is never a good idea. Here's a picture of my heads where the hole is visible (top left):



I suggest starting with a new set of rocker studs (or at least just replacing the one problematic one, adding some thread sealant per GM spec.).

shbox

That's what I thought, too (the factory holes are blind), but I did not have a head to go out and verify. The only time I have heard of any leakage is when someone ports them too far and breaks into the bottom of the stud hole.

For the OP, I find it very strange that factory studs would back out. Perhaps they need to be redrilled/helicoiled. I suspect that the original owner may have known more about the situation than he let on.

Doughboy692

Ramair95ta
Did you fill the bottom of the rocker stud hole back in form inside the port to smooth the top of the port back out? If not next time you have these heads on a flow bench try it I think you will like what it does for your flow numbers. Reher Morrison sells some nice epoxy to do this.

RamAir95TA

iTrader: (2)

The heads were installed as is. After some research, this is very common with aftermarket ported heads and no mention of filling the holes back in was ever suggested from the porter.

leadfoot4

iTrader: (1)

I agree!

I've had 3 different sets of studs in my '96 LT1 heads....the OEs, and both the long and short ARPs, when I used two different styles of poly locks. Never did I have any problem with them backing out. Torque spec for the studs to the heads, BTW, is 50 ft/lbs.