I bent a rocker arm stud. I pulled the stud and tapped hole with 7/16-24 tap. I bought a set of threaded rocker arm studs. These studs have the hex needed to tighten them

Problem: The hex is too high and the rocker arm will not tighten down. I am told the tower needs to be machined to use these kind of studs. I really don't want to pull the head to bring it to a machine shop.

I read that there are studs available that do not have the hex. They can be tightened into the head by locking two nuts on the rocker arm side of the stud. I can't seem to locate them anywhere. Any advice on where to find these studs or an alternate fix would be appreciated. If I am going to need to pull the heads I am thinking I should just by a set of refurbished heads instead of fixing the ones on the car. I don't have that kind of money so I was hoping I could fix my screw up. Thanks!

 

Such studs used to be available from Dorman.

7/16-24 is not a standard thread of any kind. Not sure hwere you could have got a tap like that. That's going to create a problem.

 

ooops

 

Sorry,

Typo. Stud is 3/8 on the rocker arm side and 7/16-14 on the head side. I found some of the studs I was talking about on ebay. Racing Perfomance Parts makes them. I called the supplier and he couldn't confirm the thread type but indicated they were standard. I ordered a set and will try them when they arrive. I have my fingers crossed that it will work. I will post link and part number if it works.

If it doesn't I am thinking of going with a set of new or refurbished heads depending on $$$$$. Any recommendations on the type of heads that are a good replacement would be appreciated. I am told GM Vortec heads are a good choice but I don't know if there is a specific model, casting, etc that will work on a 305 TBI motor in an 89 RS. Again comments would be appreciated.

 

I got a set of these earlier this year:

http://www.summitracing.com/parts/MRG-1076/

They don't have the hex part, but do still have a small shoulder that you will need to check for clearance. Like you, I was only doing 1 stud, ended up with about .1 clearance to the bottom of my stock rockers.

What bent the original stud? In my case, I broke the original pressed-in stud, replaced with one of the above, and then broke that too. I had just done a cam swap with increased lift, and just the one rocker was barely kissing the stud at the extreme ends of it's travel. They lasted about 500 miles each.

I ground the rocker slot a bit longer and put in a third stud, been golden about 3500 miles now.

 

I got a set of these earlier this year:

http://www.summitracing.com/parts/MRG-1076/

They don't have the hex part, but do still have a small shoulder that you will need to check for clearance. Like you, I was only doing 1 stud, ended up with about .1 clearance to the bottom of my stock rockers.

What bent the original stud? In my case, I broke the original pressed-in stud, replaced with one of the above, and then broke that too. I had just done a cam swap with increased lift, and just the one rocker was barely kissing the stud at the extreme ends of it's travel. They lasted about 500 miles each.

I ground the rocker slot a bit longer and put in a third stud, been golden about 3500 miles now.

 

I bent the stud with a spring compressor from summit racing that uses the rocker arm stud for leverage. The tool doesn't put pressure straight down. I pushed too hard and bent the stud. I bought a different tool to replace the remaining valve seals. The gear pulled type worked a lot better

 

you could gain a good deal of insite reading these threads

http://forum.grumpysperformance.com/...s+rocker#p7416

http://forum.grumpysperformance.com/...php?f=52&t=181

http://forum.grumpysperformance.com/...php?f=52&t=399

http://forum.grumpysperformance.com/...+rocker#p12798

http://forum.grumpysperformance.com/...+rocker#p17237

http://forum.grumpysperformance.com/...s+rocker#p7513

 

The one I bought did the same thing, it also made it impossible to put the o-rings on the valves (for what they're worth). I pulled off the foot part and fine-tuned it in a vice, got it to compress down nice and straight.

 

So unfortunate that a bad tool design can totally nuke ya!.

 

Installed a new hex head type rocker arm stud and head would need to be milled down for the rocker arm to be tightened. As I was hoping not to pull the head I found none hex head studs on eBay. Once installed rocker arm still too high. I had to run a die down the stud to run the threads further down the stud. I was able to set the lash and I am putting everything back together. I have my fingers crossed that motor will run after all is said and done. I was able to replace the valve seals so hopefully the car won't smoke when starting or after idling and taking off

 

WHOA DUDE before you try to start it! By extending the threads down, you have moved the rocker down - just make sure the bottom of the rocker is not going to contact the shoulder on the stud, or the stud boss, anywhere in it's travel.

Turn it over by hand a couple of times first.

 

Thank you TreeFiddy. I will do that

 

Hello. Me again. I got it all put back together and car turns over and sounds good. I am getting spark and the TBI appears to be shooting gas as it should. When I crank it, it will start and run rough for about 2 seconds. After that is just spins. I think it floods. Next day same thing. I thought I was going to have to pull the heads to fix my rocker arm problem and pulled the distributor. I marked how it came out but then without thinking I turned the motor to install valve stem seals and then adjust the rocker arms. So my marks were worthless. I turned the motor over until I felt air coming out of cylinder 1. Presumably the compression stroke. I brought the timing mark up to TDC. I assumed at that point I was top dead center and not 180 degrees out. I installed the distributor with the rotor over cylinder 1. Hook up all my wires making sure they were all correct. I marked the distributor lockdown bracket and distributor to insure I put the advance back where it was before I took it apart and put it back to the mark. It seems as if the car is out of time or I am totally missing something. If you all have any ideas on what I can check I would be much obliged. I am out of ideas. Note: I do have a timing light but I can't see the timing mark on the timing gear cover as the water pump is in the way. Is there any other way to check the timing. Thanks

 

CHINA!!! DOH!!!

 

Easiest way to set the "timing":

Find #1 firing by compression (as you describe); look or feel inside the cyl through the plug hole with something ... harmless, such as a tie-wrap. Turn the crank by hand, WITHOUT using the damper bolt, until the piston is at TDC. Make a mark on the damper that lines up with the mark on the timing cover.Turn the crank just under 2 full turns, until the new mark on the damper is about 6° or so before the point you think you'd like to set the timing to (say, you think you want it at 8° BTDC for whatever reason, then put the mark at 14° BTDC). Drop the dist in, line it up with the oil pump so it drops all the way in, and tighten the bolt until it's hard to move it but still possible. Pull up on the rotor and turn it against the gear CCW with one hand. Look at the little "star wheel" teeth in the dist; turn the dist body until they just exactly line up. Put the plug wires on the cap, starting at the tower the rotor is now pointing to as #1; CW in the firing order 18436572. While it doesn't "matter" where #1 is, as long as the rotor points to it when #1 is supposed to be firing, the wires will lay alot neater if the dist is oriented the way the factory puts it; which is, #1 just to the driver's side of straight ahead.

The timing tab on these cars is EXTREMELY easy to see, by looking straight down between the water pump and the timing cover. That's why they put it there... nothing is EVER in the way if the car is assembled correctly.