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Certified Rennwerker
Join Date: Oct 2002
Location: Kansas
Posts: 1,906
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Extractor size...method?
I just broke the head off a 6mm head bolt, the one on the forward area of the head near the coolant hose housing. 2 of them one taller, I snapped the smaller one. Only fastener left to pull the head off and I am stuck.
What is needed to extract this broken bolt out. Size of drill bit used and extractor size/type used..............I also need a new bolt if anyone has a spare lying around. Thanks in advance.........oh and hurry it has been 9 months since I drove this beast, help me get back to running!!.....I am sure you all can understand!!  Dal
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PCA " I've been everywhere, done everything......just can't remember any of it!" 
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08-31-2007, 08:27 AM
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Greasy Member
Join Date: Mar 2006
Location: Indiana
Posts: 1,457
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Did it break off flush to the head, or is there a bit exposed?
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Owner: Bennington Motorsports www.benms.com Sponsor for Midwest Region 944-SPEC racing series -When was your timing belt changed or tensioned?? -Yes, I'm the crazy man that will loan out my 9201. Just PM me, I will add you to the list and get it out ASAP. |
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08-31-2007, 08:31 AM
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Certified Rennwerker
Join Date: Oct 2002
Location: Kansas
Posts: 1,906
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Quote:
Just below, almost flush. Head snapped off only.
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PCA " I've been everywhere, done everything......just can't remember any of it!"
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08-31-2007, 08:32 AM
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Greasy Member
Join Date: Mar 2006
Location: Indiana
Posts: 1,457
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If your lucky...
First use a center punch to make an indent on the exposed surface of the remaining offending bolt. I'm not sure what size drill bit you would want to use without the bolt in front of me, but the rule of thumb is 1/3 - 1/2 the diameter of the bolt (thus leaving enough metal to to bite into without tearing it apart. Then tap in an easy out. There are a couple different kinds, one had reverse threads for gripping in deeper the harder you twist, the other is a square shaft with biting corners all along the length of the shaft to grip the bolt. Sometimes the revers threaded ones will slip and tear at the bolt, but then again there are times the square ones will brake off in the bolt... it's kinda your choice. If neither of these methods work, there is always the multiple drilling option. Start with a small drill bit and drill the center of the bolt out, then progressively increase the size of the drill bits until you have actually started to bite into the head material. Then use a (gulp) helicoil to repair the threads. Not a great option, but sometimes, it's the only option left.
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Owner: Bennington Motorsports www.benms.com Sponsor for Midwest Region 944-SPEC racing series -When was your timing belt changed or tensioned?? -Yes, I'm the crazy man that will loan out my 9201. Just PM me, I will add you to the list and get it out ASAP. |
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08-31-2007, 08:43 AM
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winter-hater club member
Join Date: Oct 2003
Location: salt lake city, utah
Posts: 24,705
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we just did this on my friends 944, same bolt exactly. we did the step up method until it was nearly to the threads, then i retapped it. we are going to use a stud instead of a bolt and use the stiffest loctite made to stick it in there.
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2000 Corvette - ????, 2007 Buell XB9R - Astrid, 1996 Discovery - Piglet, 2000 Forester "COOL PRIUS!" - Nobody Ever |
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08-31-2007, 09:12 AM
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Certified Rennwerker
Join Date: Oct 2002
Location: Kansas
Posts: 1,906
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My plan is to punch, drill and extract but lost as to what extractor or size, believe it or not never had a busted bolt in my half a century, plenty of stripped threads but none w/the head snapping off. Looks like the bolt shaft is about 3/8ths to a 1/4 diameter so I imagine a 3/16ths drill will cut the mustard. Is the extractor needed the tapered, spiral flutted type?
thnx....Dal
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PCA " I've been everywhere, done everything......just can't remember any of it!"
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08-31-2007, 09:26 AM
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Registered
Join Date: Jul 2001
Location: Edmonton, Alberta, Canada
Posts: 4,530
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Weld a nut and back it out....
The heat from welding will also help loosen it. ..... even seized bleeder screw that snapped flushed with the caliper will come out easily like this.
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Alex - PCA Polar Region - Boxster Muncher 86' 944 Turbo - Megasquirt - 326 rwhp/340lbft @ 18 psi SOLD www.edmontonhomelife.com www.edmontonrealestate.ws |
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08-31-2007, 09:43 AM
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Certified Rennwerker
Join Date: Oct 2002
Location: Kansas
Posts: 1,906
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No way to weld a nut on and I am not touching any aluminum with a welder, you haven't seen me weld!
Thnx Dal
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PCA " I've been everywhere, done everything......just can't remember any of it!"
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08-31-2007, 09:50 AM
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Registered
Join Date: May 2005
Location: Brentwood, Tennessee
Posts: 385
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Am I missing something here? Just lift the head off. The bolt goes all the way through the head and is threaded into the block. When you remove the head, the shaft of the bolt will be exposed and you can remove it with vice grips.
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08-31-2007, 09:52 AM
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Certified Rennwerker
Join Date: Oct 2002
Location: Kansas
Posts: 1,906
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You are correct jwade........At first I thought it was threaded but the head popped right off. I have the bolt extractor for this application. The bolt is being soaked now before attempting removal. Well I do not see any valve damage either but some pitting of the head is noticable and much corrosion of the gasket. The gasket is in one piece though. One valve looks like it was salt/carbon corroded.
 Dal
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PCA " I've been everywhere, done everything......just can't remember any of it!"
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09-01-2007, 08:39 AM
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Back from Beyond
Join Date: Nov 2004
Location: Alberta, Canada
Posts: 2,697
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jwade944 beat me to it. I broke this bolt too and just took the head off and then removed the shaft.
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'88 944 Auto - project, kinda '87 944 Auto - died saving my wife '84 944 5SP - crushed under shop roof during snow storm All others GONE! |
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09-01-2007, 10:41 AM
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Nobody Special
Join Date: Jul 2003
Location: NorCal
Posts: 522
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I'd soak that bolt in Kroil first for a day or two. Even heating doesn't seem to help that much if it's corrosion...do not use an oversize helper bar, it will only break again. When you reinstall a new one be sure and slather that thing up with all the copper based anti-seize it will take. Those bolts are notorious for shearing off.
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09-01-2007, 11:45 AM
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