leasonusa

My 81 all of a sudden started running on seven, after half an hour of investigation I pulled out the valve cover to find out that the number 3 intake rocker arm stud broke clean off!! Do these studs have threads or are they pressed in since there is a cotter pin holding it in place? Funny thing is that I have another motor from an 80 parts car and it does not have the cotter pin on the studs??? Does anyone have an idea how am I going to remove the broken stud.....

Thanks

Manuel Azevedo

Stock they do not have a pin holding the stud. This was something that use to be done to keep the studs from pulling out. If you only have one that is pined it probably was pinned because of a prior problem on that stud. The repair for your problem is going to require removal of the head and drilling the old stud out and going with screw in studs. But I do not think the stock heads are really worth doing that too. Seems your in for a new head cost wise or up grading to better heads which is probably your best bet unless you are looking for originality in which case you need to replace the head with a like head, that would be the cheapest way.

Tim81

Manuel is right, If the last three digits of your head casting number end in 624 then they are probable not worth fixing. If money is a problem for you, try finding a nice used set of iron heads to replaced the ones you have now. If this is a stock motor look for heads from the mid 70s 441,487, 993, they might not be the best but you can find a set of good 882 heads easily for a couple of hundred bucks and then of course the Vortec guys will chime in about going that route. Really all comes down to how much you can afford...Good Luck

Gordonm

I really hope you are joking by saying a cotter pin is holding the stud in. Even a roll pin would be a joke. I hope it is a solid pin. I have seen this and this is a poor fix at best. On a low lift cam maybe it will work but any perfromance cam it will be trouble down the road.

jackson

yes, that pin is probably there because there has been a problem w/ loose press-fit stud.

check w/ your local auto machine shop ... Pioneer brand & others offer OVERSIZE press-fit studs ... if yours is not already oversized, then it should not be too pricey to fit one ... they work just fine with OE-type valve springs. Tip: a shop that's primarily a hi-po shop is Not likely to have much real experience with oversize studs ... but one with lotsa fleet work will.

However, If yours also has hi-pressure aftermarket performance valve springs, they will eventually hasten press-fit studs to loosen & fail.

CA-Legal-Vette

I'm with Manuel and Tim. If at all possible in your budget, replacing the heads will be your best bet. My old 81 REALLY liked Summit iron heads with 64 cc chambers. You could certainly repair your current heads for less money though.

leasonusa

The engine was build by Five stars in Glendale AZ in March of 09 before I got the car, they made it in to a 383 with 9.5 pistons and 477/480 lift cam. apparently the drilled all rocker studs and fitted roll pins in all of them. By doing this the studs are week where the wholes are and that is why it broke off along the whole, I will try and drill out the old stud and put another one in while is on the car if it works good if not I will get new heads from summit......

Thanks guys

Phil Zell

If this outfit is still pinning studs I would look elsewhere for machine work.

Jack Wood

Bust a move on a new set of heads, Ace. There's no need to try to convince the wife that's what's needed because the old ones are broken and not dependable even if repaired. It should be an easy sell to her. You've been given a golden opportunity - don't blow it with fixing the same old crappy heads up when you can have a new set and not need to fight with the wife over it like I do. "Those heads are working fine. Don't fix it if it ain't broke." - see what I have to listen to? Seize the moment!

bobs77vet

how much of the stud is remaining?

heres some ideas on what to do and be sure to check valve train geometry when you are done

Ben Lurkin

WHATEVER you do, DO NOT try drilling the broken stud by hand. Where, exactly did the stud break at? If it is above the boss, it can be removed without damaging the head fairly easily and another one installed while in the car. Othewise, Manuel is right. Do you have a pic you can post? Having the studs pinned won't weaken them enough to make a difference (assuming it was done correctly).

tfi racing

But if that is all the customer is willing to accept,what other choice does the shop have...

Lemans Blue 69

Interesting post. Just curious. Does anyone know for sure if the 1969 L46 had pressed in studs or were they threaded. That's what I own.

Gordonm

They should be pressed in studs.