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Head bolt nut question
Posted by: Vin ()
Date: April 14, 2018 10:38AM

Poking around the car this morning I found an unwanted surprise. I have an upper head bolt nut that did not appear to be tight. I could see the nut sitting out from the head maybe 1/16 inch, enough that I could get the tip of a pick behind the nut. I tried to torque it down but after a little movement the wrench won't go more and then the wrench springs back to the starting point when I release pressure. I can also see that the nut next to it has a washer under it while none of the other nuts do but it is tight to 30 ft lbs as are the rest of the uppers. Any idea why this nut won't tighten and Springs back? Wondering if the stud is turning then hitting resistance and pushing back. I tried turning the nut off and it won't go far until it stops turning I think because of some rust on bolt threads. I am thinking I will need to get the nut off and see if the stud is stable or if it turns out with the nut. Any thoughts?


Vin
Dayton, OH
1965 Corvair Monza Convertible (4 speed)

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Re: Head bolt nut question
Posted by: MattNall ()
Date: April 14, 2018 11:10AM

Penetrant... clean the rust.... maybe some heat and beeswax...

Add the washer.... retorque





MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

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Re: Head bolt nut question
Posted by: cnicol ()
Date: April 14, 2018 11:46AM

What Matt said plus: Don't force the nut over the rusty thread.

Clean and oil them thoroughly. If the nut gets stuck on the threads, the stud will start turning and unscrew from the block. Not the end of the world but it's better if it's left right where it is in the block.

Craig N. Coeur d'Alene ID.
66 Black Monza 4dr, 4.2L V8 49k
61 Seamist Jade Rampside 140 PG
60 Monza coupe (sold, sniff sniff)
66 Sprint Corsa convt - First car! Re-purchased 43 years later
2+2 gnatsuM 5691

+17 Tons of parts

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Re: Head bolt nut question
Posted by: Vin ()
Date: April 14, 2018 11:57AM

So just retorquing the one nut is ok? I won't need to redo them all in sequence?


Vin
Dayton, OH
1965 Corvair Monza Convertible (4 speed)

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Re: Head bolt nut question
Posted by: Phil Dally ()
Date: April 14, 2018 12:06PM

Saw an ad these new super trick head nuts in the Communique this month.

Corvair Stuff By Russel Davis (757) 642-0665 Set of twelve for $50 bucks.

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Re: Head bolt nut question
Date: April 14, 2018 12:17PM

Those upper nuts are a real pain, mostly because they are in a perfect place to collect all the ingredients for corrosion.
Definitely use some heat, I use a heat-gun from Harbor freight. I use birthday candles for easy to apply wax after the heat action (about 4-5 min on high a couple inches away from the stud/nut.
Use a wire brush to clean the debris/rust away from the exposed thread area. Again, H.F. sells inexpensive "toothbrush" size wire brush sets.

Move the nut in each direction until you feel it getting tight, then reverse it and run it a couple of turns, then clean the threads again and apply more heat/wax as needed.

When they are all cleaned/derusted I like to coat them with anti-seize compound as a protectant. Then buy some flexible vinyl tube caps that will pushover the nuts and keep them clean.


Dan Davis ~ Pierce County, WA ~ CORSA Western Director + Corvairs NW + North Cascades Corvairs + Corvanatics
1966 Corsa Turbo coupe ~ ~ 1966 140 Corsa ~ ~ 1965 Monza 140/4 'Vert Sierra Tan/Fawn ~ 1964 Monza 'Vert (SOLD) ~ 1960 Monza Ermine White/Red PG ++ ~ 1965 Monza 140/4 Evening Orchid w/ ivory/black interior ~ 1962 Monza Wagon 102/4 ~ 1963 Rampside/Scamper ~ 1963 Red/Greenbrier ~ 1969 Ultra Van #468

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Re: Head bolt nut question
Date: April 14, 2018 12:35PM

Couple of photos of that cap I suggest.





My local plastic warehouse has 'em in bins for cheap.


Dan Davis ~ Pierce County, WA ~ CORSA Western Director + Corvairs NW + North Cascades Corvairs + Corvanatics
1966 Corsa Turbo coupe ~ ~ 1966 140 Corsa ~ ~ 1965 Monza 140/4 'Vert Sierra Tan/Fawn ~ 1964 Monza 'Vert (SOLD) ~ 1960 Monza Ermine White/Red PG ++ ~ 1965 Monza 140/4 Evening Orchid w/ ivory/black interior ~ 1962 Monza Wagon 102/4 ~ 1963 Rampside/Scamper ~ 1963 Red/Greenbrier ~ 1969 Ultra Van #468

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Re: Head bolt nut question
Posted by: Vin ()
Date: April 14, 2018 01:31PM

Thanks all. Kroll, heat and wax, a.wire brush, repeat and a light touch on the breaker bar and the nut came loose. Got it off. A few things to ask. The stud seems secure but the tip of the stud can be wiggled some. Is that normal? Second I found a lock washer under the nut. I think the nut is the original kind with a built in collar so should a washer or lock washer be used? Finally, can I reuse this nut or do I need a new one?


Vin
Dayton, OH
1965 Corvair Monza Convertible (4 speed)

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Re: Head bolt nut question
Posted by: MattNall ()
Date: April 14, 2018 01:59PM

Normal!

Use the flanged nut with a Flat washer that is oiled on the side that the nut pushes against..

All you want is a REAL 30 ft. lb.. Lubed or dry threads make no difference on this type of "Fix"





MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

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Re: Head bolt nut question
Posted by: Vin ()
Date: April 14, 2018 06:33PM

Thanks again for all inouts. Success. I got it torqued to 30 ft lbs without incident. Started and let it run and all seems well. I wonder if there was a washer behind the lock washer (a previous owners work years ago) and the washer cracked and eventually fell out behind the nut and lockwasher leaving the gap behind the nut. It was torqued because the lock washer left some digs in the flat part of the nut. Anyway, I had been chasing what I thought was an odd miss and I wonder if it was actually caused by the head gasket not being tight here. Seemed to idle better but maybe in my mind. It rained all day so I couldn't take it on the road to try. But happy I got this fixed without too much trouble!


Vin
Dayton, OH
1965 Corvair Monza Convertible (4 speed)

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Re: Head bolt nut question
Posted by: MattNall ()
Date: April 14, 2018 06:45PM

Unlikely a miss... usually head gaskets "chirp"

I'm proud of you only doing what was needed to fix a problem..





MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

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Re: Head bolt nut question
Posted by: Frank DuVal ()
Date: April 14, 2018 07:32PM

Russel started making those head nuts after he had some brand new flanged nuts strip out before reaching 30 ft -lb of torque. They look great!

Glad you got it fixed, Vin!smileys with beer

Frank DuVal

Fredericksburg, VA

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Re: Head bolt nut question
Posted by: JimBrandberg ()
Date: April 16, 2018 05:46AM

I use roller rocker hold down nuts as head nuts on my race engine. My problem with milled heads and stock nuts was going down past the threads. A bonus with these nuts is an allen set screw to lock it in place. Also maximum thread engagement.

I just buy stock plated head nuts from Clarks and haven't had any trouble. I do only chase the threads with an oiled Grade 8 nut and don't use a die unless necessary. My theory is a die removes some material which could cause the nut to be loose, I could be wrong. I wonder if the steel non-plated nuts are a little tighter than the plated ones.

Jim Brandberg
Isanti, MN
CorvairRepair.com

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Re: Head bolt nut question
Posted by: jjohnsonjo ()
Date: April 16, 2018 06:20AM

Even Clarks recommends not re-using their head nuts. They are softer than the factory ones and will not always torque right the second or third time.

J.O.

65 Corsa Turbo Vert
79 Honda XL 500S
69 Honda CL 160 D
2010 BMW F 650 GS
2003 Bounder 36D
2013 KIA Optima SX turbo-AKA ZIPPY (wife,s car)
69 Newport Holiday Sailboat
Baja 150 dune buggy cart
Coleman HS 500 UTV
2016 KIA Sorento SXL Turbo

Bethlehem,Pa

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