Rocker arm broke clean off
Thread Starter
2nd Gear
Joined: Oct 2008
Posts: 2
Likes: 0
Rocker arm broke clean off
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
Thanks
Burning Brakes
Joined: Jan 2007
Posts: 1,057
Likes: 4
From: Concord Calif
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
Thanks
Burning Brakes
Joined: Aug 2006
Posts: 1,058
Likes: 27
From: Eastern North Carolina
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
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
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.
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
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.
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.
Race Director
Joined: Jul 2004
Posts: 12,702
Likes: 329
From: Scottsdale Arizona
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.
Thread Starter
2nd Gear
Joined: Oct 2008
Posts: 2
Likes: 0
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
Thanks guys
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Instructor
Joined: Jan 2008
Posts: 208
Likes: 0
From: McDonough GA
You have been given a golden opportunity to buy new heads!
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!
Race Director
Joined: Sep 2004
Posts: 11,874
Likes: 263
From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
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
heres some ideas on what to do and be sure to check valve train geometry when you are done
Last edited by bobs77vet; May 13, 2011 at 03:53 PM.
Le Mans Master
Joined: Dec 2006
Posts: 5,557
Likes: 9
From: Oquirrh Mountains
St. Jude Donor '09
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
Thanks guys
Drifting
Joined: Jan 2006
Posts: 1,832
Likes: 38
From: Cedar,BC
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
