Head stud torque

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my65
Posts: 155
Joined: Tue Dec 01, 2015 12:20 pm
Location: porter texas

Head stud torque

Post by my65 »

My 65 110hp had an engine rebuilt back in 2014 by the previous owner. The car runs well except the number 2 cy has always had a noise valve. I have adjusted it twice and the last time, I put a new set of rocker nuts ( Clark’s C1157A) on all the valves on the left side. This last weekend, several members in the club commented on my loud valve noise on the left side. Yesterday I removed the valve cover to replace the lifters in the number 2 cylinder. When I removed the rocker arm, the first head stud came out with the rocker!!!😳 I dismantled the rockers from the rocker studs an here is my question?!?! I can reinstall the head stud and torque it with the head in place. :think: Is it acceptable ( since both are torqued to 30 ft. Lbs. ) to install the stud and use the rocker stud to torque both at the same time???
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Ed ( my65 )
65 Monza Convertible
110 HP 4 Speed
63 Monza Coupe
140 HP 4 Speed
66 Corsa Coupe
140hp 4 speed
Porter, Texas
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terribleted
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Location: Atlanta, GA
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Re: Head stud torque

Post by terribleted »

Not the recommended procedure (install slightly oversized stud), but, I have done this a number of times and as long as they have taken torque without pulling they worked fine.

The end valve in your photo is badly mushroomed it looks like. The ends should not be mushroom shaped at all. That valve needs to be replaced and very well (in conjunction with is rocker which must also be worn could easily make your noise. I would expect a worn valve guide or guides. Looks like it is time to rebuild at least the heads. Looking again at your photos that same rocker has the nut A LOT tighter than the one next to it. All nuts of the same type should show a very similar number of threads generally this is another clue to issues in this valve. A malfunctioning lifter could over time cause this damage. I would want to at least peer in, (when the head is off to replace the valve) to see what that camshaft lobe looks like as well.
Corvair guy since 1982. I have personally restored at least 20 Vairs, many of them restored ground up.
Currently working full time repairing Corvairs and restoring old cars.
https://www.facebook.com/tedsautorestoration/

Located in Snellville, Georgia
Wagon Master
Posts: 474
Joined: Thu Jul 28, 2011 6:36 pm

Re: Head stud torque

Post by Wagon Master »

My take.
You've had to keep readjusting the noisy valve because the stud has been slowly pulling out of the block. By either pulling the block threads or just unscrewing. Adjust valve. Puts pressure on stud. Stud pulls. Rocker gets noisy. Repeat. Repeat. Stud finally gave up. Valve head got mushroomed from loose rocker arm hammering on it.
What I'd do if the stud will torque to 35 ft. lb.
Clean block end of stud and block stud threads with Brak-kleen.
Put a couple small ball bearings or a dowel pin in the rocker arm stud. Anything to keep the head stud from bottoming out in the rocker arm stud but not jam.
Apply red Loctite to head stud and install in block till 35 ft. lb. of torque is reached OR stud is at same height in the head as the others.
Grab head stud with Vise-Grips to insure it won't rotate and remove rocker arm stud. Remove what you put in the rocker stud.
Let set at least and hour and reassemble with new or good used rocker if old one has significant wear it valve tip.
Adjust valves and button it up.
I wouldn't worry about the valve tip until it's time for an engine overhaul.
Motor on!

If stud will not torque to 35 ft. lb., you can install an over-sized stud, a Heli-Coil or Time-sert in the block without removing the head but it takes specialized tools.
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terribleted
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Re: Head stud torque

Post by terribleted »

Is possible the head stud was loose or pulling out. If it was loose you should have felt it when you removed it. If it has pulled the threads it will not properly torque down.
Corvair guy since 1982. I have personally restored at least 20 Vairs, many of them restored ground up.
Currently working full time repairing Corvairs and restoring old cars.
https://www.facebook.com/tedsautorestoration/

Located in Snellville, Georgia
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