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Re: Need input on drilling block for new head studs.
Posted by: 63 Spyder Ragtop ()
Date: January 12, 2020 07:14AM

The studs that I purchased from Clark's are the Pro-Super Duty Head studs here:

[www.corvair.com]

Clark's states specifically that there is no need to use an insert with these studs even if the stock stud has pulled out.

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Re: Need input on drilling block for new head studs.
Posted by: 66vairman ()
Date: January 12, 2020 11:40AM

63 Spyder Ragtop Wrote:
-------------------------------------------------------
> The studs that I purchased from Clark's are the Pro-Super Duty Head studs here:
>
> [www.corvair.com]
>
> Clark's states specifically that there is no need to use an insert with these studs even if the stock stud has pulled out.

I think you mis-read Clark's page. A quote from Clark's page --- "If the stud has actually pulled out, you must use a thread insert. Buy our kit and save the bother of transporting engine to a machine shop."

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Re: Need input on drilling block for new head studs.
Posted by: idiyaught ()
Date: January 12, 2020 11:47AM

He read correctly
The larger size at the block allows you to tap (use std GH3 tap) and directly install these studs without using an insert (even if a stock stud has "pulled out").
Does not say if interference thread or loc-tight needed

John Oostdyk
Thornhill, Ont
63 Rampy
65 Greenbrier
64 Convertible

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Re: Need input on drilling block for new head studs.
Posted by: 66vairman ()
Date: January 12, 2020 11:49AM

JimBrandberg Wrote:
-------------------------------------------------------
> I'm sorry I misunderstood that you already have the studs out so my previous post does not apply.
> I agree that the stock studs are special. Very hard and tough to reform with a regular grade die.
> I usually stay with the stock stud unless I have to change.

A standard die will NOT cut the stud threads effectively. I purchased a top quality die from a machine shop supply house and the ONLY cutting lubricant that prevented galling was STP oil additive (believe or not it worked well and the threads were smooth). The stock studs are TOUGH!

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Re: Need input on drilling block for new head studs.
Posted by: jjohnsonjo ()
Date: January 12, 2020 12:00PM

PRO-SUPER DUTY HEAD STUDS: These studs (8700 heat treated steel) are 7/16" where they go into the block and taper to 3/8" giving considerably more strength. The larger size at the block allows you to tap (use std GH3 tap) and directly install these studs without using an insert (even if a stock stud has "pulled out"). The larger block diameter also makes it less likely a stud will ever "pull out" again. You can see the difference compared to an original stud. These are suggested with ALL roller rockers and great insurance for a "stock" engine.

I'm reading you don't need inserts with the studs he purchased

Agreed on the die, I even wiped out some good ones cleaning up the threads on the head ends.

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





Edited 1 time(s). Last edit at 01/12/2020 12:03PM by jjohnsonjo.

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Re: Need input on drilling block for new head studs.
Posted by: 66vairman ()
Date: January 12, 2020 12:11PM

idiyaught Wrote:
-------------------------------------------------------
> He read correctly
> The larger size at the block allows you to tap (use std GH3 tap) and directly install these studs without using an insert (even if a stock stud has "pulled out").
> Does not say if interference thread or loc-tight needed

I stand corrected! -- The Clark's standard replacement stud requires an insert if the original stud pulled out, but Clark's states the Pro-Super Duty studs DO not need an insert to replace a pulled out stud, but the hole should be tapped.



Edited 1 time(s). Last edit at 01/12/2020 12:28PM by MattNall.

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Re: Need input on drilling block for new head studs.
Posted by: jjohnsonjo ()
Date: January 12, 2020 03:37PM

I didn't know these things existed up until a few hours ago. Has anyone installed them. I remember reading a while back that the aircraft guys wouldn't run Clark's repros, but I never heard these mentioned.

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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Re: Need input on drilling block for new head studs.
Posted by: 63 Spyder Ragtop ()
Date: January 12, 2020 03:42PM

I'll be installing them tomorrow probably, I'll let you know how it goes.

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Re: Need input on drilling block for new head studs.
Posted by: jjohnsonjo ()
Date: January 12, 2020 04:16PM

Do you have a drill press to keep everything straight.

Also, we used this stuff at work, I bought my own after I retired. I life long machinist put us on to it.


[www.amazon.com]

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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Re: Need input on drilling block for new head studs.
Posted by: 63 Spyder Ragtop ()
Date: January 12, 2020 04:56PM

jjohnsonjo Wrote:
-------------------------------------------------------
> Do you have a drill press to keep everything straight.
>
Yes, I have a drill press, have made sure plate is perpendicular to the bit, have drilled all of the holes and one half is already tapped. I'll finish tapping the other half tomorrow and begun to install the studs. I've had these studs for 3 years now.

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Re: Need input on drilling block for new head studs.
Posted by: jjohnsonjo ()
Date: January 12, 2020 05:22PM

Sounds good, make certain that you DO NOT go too far in with the studs that are going into non blind holes, or it will hit something when its all together.

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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Re: Need input on drilling block for new head studs.
Posted by: 63 Spyder Ragtop ()
Date: January 12, 2020 05:31PM

I also bought this head stud installation tool:

[www.corvair.com]

It's the very top item. It makes sure that the studs go in at the correct depth and torque.

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Re: Need input on drilling block for new head studs.
Posted by: JimBrandberg ()
Date: January 13, 2020 05:59AM

Okay I thought all along that you were using the oversize studs that are just slightly bigger than 3/8. I didn't know that you are using studs that have 7/16 bottoms and of course would need to be drilled and tapped. Sorry that I caused more confusion with no help.
I also didn't remember that these studs existed and have always used some sort of an insert if it got that far. I will file it away as a possible alternative in the future. I've been working on Corvairs for a long time but learn new things here all the time.
I had quite a time a few years ago where some gorilla had apparently torqued the head like it was a Small Block Chevy. it added plenty of adventure to a pushrod tube o-ring job.

Jim Brandberg
Isanti, MN
CorvairRepair.com



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Re: Need input on drilling block for new head studs.
Posted by: 63 Spyder Ragtop ()
Date: January 13, 2020 12:07PM

Well, I'm having a problem installing the studs with the tool that I purchased from Clark's. Out of 6 attempts I've only gotten one to stay in the block. The rest have backed out trying to remove the top cap. A ballbearing is supplied that sits atop the stud so the cap doesn't "lock" onto the stud but only one has released allowing the stud to remain in the block. The top cap easily threads onto the top of the stud with no resistance until it contacts the bearing. I've tried using less anti seize on the block end, I've tried installing dry and even tried oil on the top threads that the installation cap threads onto and it still backs the stud out. I've contacted Clark's and their technician has never heard of this issue. He did confirm that it was correct to use a standard 7/16×14 tap for the holes. He thinks that there may be some issue with the internal threads near the top of the cap and ig going to try to send me another cap to try. confused smiley

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Re: Need input on drilling block for new head studs.
Posted by: Spectre ()
Date: January 13, 2020 12:14PM

First, I'd locktite them in the block. I would not use antiseize on the block end of the threads.

David Clamp


1965 Corsa convertible - 140 4spd/3.55/AM-FM

2013 Mustang GT convertible - 5.0, 6spd auto, Procharger i-1

2003 Miata SE - 6spd manual (wife's toy)

"Victory is mine!" - SG

Norman, OK

<a href="[www.wunderground.com] src="[weathersticker.wunderground.com]; alt="Click for Norman, Oklahoma Forecast" height="90" width="160"></a>

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Re: Need input on drilling block for new head studs.
Posted by: 63 Spyder Ragtop ()
Date: January 13, 2020 12:35PM

Spectre Wrote:
-------------------------------------------------------
> First, I'd locktite them in the block. I would not use antiseize on the block end of the threads.


What are the chances that I wouldn't get the stud all the way in before it started to set up?

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Re: Need input on drilling block for new head studs.
Posted by: joelsplace ()
Date: January 13, 2020 12:41PM

Maybe use an impact to remove the cap?
Do the studs take a lot of force to install but the cap is just really stuck?

Joel
Northlake, TX
5 Ultravans, 113 Corvairs and counting...

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Re: Need input on drilling block for new head studs.
Posted by: 63 Spyder Ragtop ()
Date: January 13, 2020 12:54PM

I'm not real happy with the Clark's tool. In theory it might have been a good idea but the application isn't satisfactory in my opinion. The first pictue shows the tool in application but the second pic shows what happens to the block after torquing. I'm not sure the damage is acceptable since I assume there is a gasket between the cylinder and the block. What do you think? Is my block trash now? Keep in mind that my block is not as pristine as most on here. Due to the file size restrictions I can only upload this one pic, I can't reduce the other one to 500kb or less

Attachments:
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Re: Need input on drilling block for new head studs.
Posted by: 63 Spyder Ragtop ()
Date: January 13, 2020 12:55PM

joelsplace Wrote:
-------------------------------------------------------
> Maybe use an impact to remove the cap?
> Do the studs take a lot of force to install but the cap is just really stuck?

I have had some luck using an impact but my main concern is the damage to the block now.
They don't install hard, usually about 12 - 14 lbs ft until the cap seats against the heigth tube.



Edited 1 time(s). Last edit at 01/13/2020 12:57PM by 63 Spyder Ragtop.

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Re: Need input on drilling block for new head studs.
Posted by: wittsend ()
Date: January 13, 2020 01:04PM

I'm new to Corvair's but the thought of torquing heads keeps me up at night eye popping smiley. Is it possible that part of the reason studs pull out of the block is because they rotate in the torquing process? Meaning if he stud was held with a vice grip while torquing the potential to strip the case would be less? I realize the "pull" is all the same but if a stud rotates might it also be cutting the threads in the aluminum? When I removed my head nuts at the slightest hint that a stud was turning I used vise grips to stop that.

Also, as a "whatever it takes" fix has anyone ever welded a thick washer on the back side of the stud. I realize this won't work with the studs that go into the main bearing webbing. Anyway, just some random thoughts of an outsider.



Edited 1 time(s). Last edit at 01/13/2020 01:06PM by wittsend.

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