Help-valve Stud Backed Out.

[BLACK MOON]

I had a stud start to back out causing a push rod to come loose and jam up another causing it to bend. My question is 'Are the valve studs pressed in or screwed in?' I just reassembled this motor and really would like to repair it while it is together. It is the original head on a 63 - 327, 300 hp motor. Any advice would be appreciated. Thanks.

 

[WayneC]

Don't consider myself an expert, but the studs are pressed into the head. There are oversize studs available, but they require reaming the stud hole out to a specified size and pressing the new stud in, which may be difficult with the head in place. Sometimes racers drill small holes through the cast boss and stud and insert/press pins through to ensure the studs cannot lift out; that's something you may be able to do (possibly without removing the heads) to prevent further lifting.

I suspect you'll need to pull the head(s) and have the work done professionally.

 

[ChuckG]

Brings back old memories... You can replace the offending stud with a "screw in" stud. This can be done on the car....I've done it.

There are 2 types of screw in studs. One requires the head to be off...and requires the top of the "tower" where the stud presses in to be machined flat.

The other does not. Here's what to do. I borrowed a "stud replacement kit" from a friend. It contained the screw in studs, a tap, and a jig. You can buy the studs at any full service auto shop. I doubt that PEP Boys, etc would carry them. You can also buy the tap, and you don't really need the jig.

Bottom line....tap the hole...screw in the new stud. I used modelling clay "smushed" around my work area to keep any metal chips from getting into the oil. I used Loctite on the studs I've replaced.

Worked fine for me. Chuck

 

[BLACK MOON]

Thank you both. I just had those heads rebuilt and am disappointed the machine shop didn't recomend replacing them. Question though, how do I remove the stud? It has only 'raised' about 1/4" out of the hole.

Thanks again.

 

[motorman]

before you pull the stud drain the rad as some stud holes enter the water jacket. if you used heavier than stock chevy springs you will have this problem. you need to tap the thread straight so you need the fixture or a tap with a 3/8" pilot ground on the end. you can pull the stud by using a piece of pipe and stacking washers and use a nut on the stud and just keep turning the nut down.

 

[BLACK MOON]

I got the stud out. The problem now is that nobody has them on a sunday. Oh well we had a big day planned.

Thanks everyone.

 

[BLACK MOON]

Update. Found the studs at NAPA. Drilled, tapped and ready to install. It appears a little taller when installed but hopefully it wont be a problem. Thanks again to everyone here. It's a great place and couldn't have done without you guys.

 

[vettefinderjim]

Watch the RPM'S

Once you get it back running, watch the RPM'S. The other 15 studs are ready to pull out as well, especially if new valve springs were installed at the machine shop.

We have done just what you did to get us thru a 'race' weekend, but upon return home pulled the heads, and sent them to the machine shop to get all the studs replaced with screw in units.

Check your rocker arms and push rods also. The push rods will get very brittle on the ends that push the rockers, and start to disiniagrate. The rockers also will get worn with age.

Remember now, that good heads and valve train is where all the power comes from, so don't do a cheap fix. Any racer who takes his stock heads and has them cleaned up and replaces all the valve train ( and I mean all........valves, springs, guides, keepers, cam, lifters, rockers, studs, push rods) will spend a quick $1000. And if he gets the heads cc'ed, springs matched, and does a little porting, it will cost even more. But the end result will be another 100hp. And that is a lot for a small block.
Good luck