924Board.org

Chrenan · Joined: 15 Jan 2003 Posts: 3903 Location: Canada

Hi guys,

I'm having some trouble installing the exhaust manifold studs into the head. Got the studs from the dealer, part number N0444115, they look identical to the ones that came out. Is there a trick to installing them? They don't seem to want to go, they thread fine for a few threads, then get very tight. I threaded a bolt onto the long threaded end to turn the studs, but I am worried about the amount of force required.

Any tips?
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1987 951 - M193 Version for Japan

Ozzie · Posted: Tue May 02, 2006 6:40 am Post subject:

Run a tap into the hole to clean them out.
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Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance

gohim · Joined: 02 Nov 2002 Posts: 4459 Location: Rialto, CA

A tap is always a good idea after something has been to the machine shop before reassembly. Use lots of spray lubricant (like WD-40) to wash out the metal debris when you are done with the tap.

Make sure that you do not bottom out the studs when you screw them in. They do not have to tighten up before you stop screwing them in. Screw them in by hand, and stop when they are about even with the other exisiting studs. DO NOT FORCE THEM IN TO EVEN OUT THE LENGTH.

Chrenan · Joined: 15 Jan 2003 Posts: 3903 Location: Canada

Good points guys, thanks!

I know the stud is M8x30, so picking up the right tap ahouldn't be a problem.
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1987 951 - M193 Version for Japan

Smoothie · Posted: Tue May 02, 2006 9:30 am Post subject:

You need the thread pitch, which Lizard recently noted is 1.25 - http://www.924board.org/viewtopic.php?t=18895
-So the tap size to get is "M8-1.25". You could bring one of the studs along to double check it.
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"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

Chrenan · Joined: 15 Jan 2003 Posts: 3903 Location: Canada

Wow, thanks Smoothie!
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1987 951 - M193 Version for Japan

John Brown · Joined: 07 Nov 2002 Posts: 903 Location: Leesburg VA

A 'blind' or 'bottoming' tap will go all the way down. Not a Sears item but readily available on the internet.
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John
80 931 - #931 44Cup
99 Escalade - tows track cars
gone but not forgotten: original 924.org car - 82

Chrenan · Joined: 15 Jan 2003 Posts: 3903 Location: Canada

Thanks John. Haven't actually gone out to buy one yet, so that will help. Get most of my tools at www.houseoftools.com , there is a store about 5 minutes from my house, I could spend every penny I have in there, no problem.
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1987 951 - M193 Version for Japan

Min · Posted: Thu May 04, 2006 8:13 am Post subject:

Keep in mind once you've got this engine running ,that you will need to check those studs occasionally to make sure they havn't backed out of the head. I replaced all the studs when I did a full rebuild, 8 months later I was redoing it becuase some of them had backed out and snapped off. (luckily for me I could get visegrips on the ends of them this time) When I did this assembly both times i used new copper lock nuts and new studs, but the studs themselves backed out of the head. Now I check to make sure they are still tight every couple of months.

Min
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Custom means it didn't come from a box.
1980 n/a with EDIS and Megasquirt II Injection. 7 different colors and counting.

Chrenan · Joined: 15 Jan 2003 Posts: 3903 Location: Canada

I'm using new studs and copper nuts as well. Is there any way to make the studs stay first time? I'm assuming the temperatures are too high for loctite? I guess there is a risk there too that if you loctite the studs, and one snaps off, you'll never get the remainder out.
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1987 951 - M193 Version for Japan

Chrenan · Joined: 15 Jan 2003 Posts: 3903 Location: Canada

Threads tapped, problem solved, thanks everyone.
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1987 951 - M193 Version for Japan

augidog · Joined: 03 Mar 2003 Posts: 1360 Location: New Jersey

Putting my exhaust on today the last stud spun right out and looks as if it was lock- tight in. Possibly stripped in block. Can I re-tap and what size larger. Thanks.
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1978 924 95 mile daily driver.
Audi TB/POR174M/High Flow Cat/2.25" exhaust
I knew that positive thinking thing wouldn't work.

Chrenan · Joined: 15 Jan 2003 Posts: 3903 Location: Canada

Hmmm, I'm glad I didn't install using loctite.

Stock size is M8, so going up to 9 or 10mm would likely work. Tapping to a larger size is something I might have a machine shop do just to be safe.
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1987 951 - M193 Version for Japan

Smoothie · Posted: Mon May 08, 2006 11:14 am Post subject:

A thread repair insert is another option and would mean you don't have to change fastener size. "Heli-coil" is one that comes to mind, but there are others and Heli-coil wasn't the #1 preference. A search on heli-coil might bring up past discussions as well as the other brand names.
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"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

Ozzie · Posted: Mon May 08, 2006 11:29 am Post subject:

Another option is you'll find the hole goes in a fair way.
Tapping all the way to the bottom and putting an all-thread stud in may fix it.
_________________
Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance