How Screwed am I?
Thread Starter
Burning Brakes
Joined: Sep 2006
Posts: 851
Likes: 10
From: Palm City, FL
Originally Posted by Tom454
Assumptions:
1) The valve cover screw is a 1/4-20
2) The head of the 1/4-20 screw snapped off indicating that the threaded part is stuck pretty hard in the head... enough to cause
the screw head to snap off... this is pretty well "stuck".
3) The screw snapped off flush or below the head surface
4) You drilled the stuck screw to allow an easy-out to be started
5) The brittle, extremely hard, easy-out snapped off flush with the head and is still stuck in the drilled starter hole.
Using a dremel (small rotary grinder/cutter) will require you to cut the head as well as the screw & easy out. In addition, this method may not work because the screw is stuck in the hole hard enough to snap off the screw head, which is probably too hard to allow unscrewing with a screw driver. It's worth a shot, but you will damage the head in the process.
Welding a nut on the end of a flush 1/4-20 screw is going to be a bit tricky.. but once you get it welded, you can work the nut/screw clockwise & counter-clockwise and it may loosen up and come out.
Add some heat with a torch and you may increase the odds in your favor.
DIY- Heat the head and the remaining screw etc with an Oxy-Acetylene torch, hit it with WD40 on the cool down cycle, repeat a dozen times, while still hot, use a small diameter drift punch (1/16 - 3/32) to tap at the circumference of whatever is left of the screw, first in one direction, then in the other... if you can get any kind of catch point on it at all. A few taps in each direction before re-heating. The heating /cooling is what helps the screw to separate from the head.
Light taps... hard taps will destroy any grip point that you might have for the drift punch. Patience is the key.
If there is no point of contact for the drift punch, then remove the head & take it to a machine shop.
If the torch can't be used because of the screw location, then this method will probably not work with the head on the engine... you'll have to take it off. The heat is the key. A small propane torch cannot generate enough heat because it will dissipate into the head too quickly.. but that is worth a shot as well if you don't have the oxy-acet.
Last resort- a plasma cutter to blow the 1/4-20 out of the hole.
Depends on whether you have aluminum or iron heads.
Drilling an easy-out is nearly impossible... I have had to shatter them to get them out, and this causes its own set of new problems.
1) The valve cover screw is a 1/4-20
2) The head of the 1/4-20 screw snapped off indicating that the threaded part is stuck pretty hard in the head... enough to cause
the screw head to snap off... this is pretty well "stuck".
3) The screw snapped off flush or below the head surface
4) You drilled the stuck screw to allow an easy-out to be started
5) The brittle, extremely hard, easy-out snapped off flush with the head and is still stuck in the drilled starter hole.
Using a dremel (small rotary grinder/cutter) will require you to cut the head as well as the screw & easy out. In addition, this method may not work because the screw is stuck in the hole hard enough to snap off the screw head, which is probably too hard to allow unscrewing with a screw driver. It's worth a shot, but you will damage the head in the process.
Welding a nut on the end of a flush 1/4-20 screw is going to be a bit tricky.. but once you get it welded, you can work the nut/screw clockwise & counter-clockwise and it may loosen up and come out.
Add some heat with a torch and you may increase the odds in your favor.
DIY- Heat the head and the remaining screw etc with an Oxy-Acetylene torch, hit it with WD40 on the cool down cycle, repeat a dozen times, while still hot, use a small diameter drift punch (1/16 - 3/32) to tap at the circumference of whatever is left of the screw, first in one direction, then in the other... if you can get any kind of catch point on it at all. A few taps in each direction before re-heating. The heating /cooling is what helps the screw to separate from the head.
Light taps... hard taps will destroy any grip point that you might have for the drift punch. Patience is the key.
If there is no point of contact for the drift punch, then remove the head & take it to a machine shop.
If the torch can't be used because of the screw location, then this method will probably not work with the head on the engine... you'll have to take it off. The heat is the key. A small propane torch cannot generate enough heat because it will dissipate into the head too quickly.. but that is worth a shot as well if you don't have the oxy-acet.
Last resort- a plasma cutter to blow the 1/4-20 out of the hole.
Depends on whether you have aluminum or iron heads.
Drilling an easy-out is nearly impossible... I have had to shatter them to get them out, and this causes its own set of new problems.
One thing is for sure... at least I'm not the only one who has done this ha-ha.
I will give a shot to a number of the suggestions on this post tonight and let you know my results.
Race Director
Joined: Mar 2006
Posts: 14,112
Likes: 28
From: Florida
Originally Posted by Tom454
........
With an easy out broken off flush, your only option is
1-a very experienced welder using a tig machine
2-grinding the easyout/brokenbolt with a dremel/diegrinder with a diamond ball bit. Diamond and water can handle the hardness of the easyout.
I suspect the original bolt was probably too long and the bottom was jammed tight and is still very tight. Heat should also help first.
This is a job for a machinist/welder and not most mechanics nor anyone inexperienced. Generally,smaller tha bolt, the harder to do.
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
Originally Posted by RMS73
Is any of the easy-out above the bolt, if so grab it with locking pliers and pull it out twisting it for removal of the easy-out not removal of the bolt. Then drill the bolt body out. At work we drill the bolt body out and then peel out the threads out of the hole with a pick.
Roger
Roger
Last edited by 63mako; Oct 24, 2006 at 10:45 PM.
Le Mans Master
Joined: Apr 1999
Posts: 6,134
Likes: 46
From: Raleigh North Carolina
Originally Posted by 63mako
I have done this before. With patience it works fine. The EZout wil break up with a punch. Then use a small bit to drill through the center of the bolt. There should be a void under the bottom of the bolt. Then drill a little bigger and a little bigger till you just touch the threads with the bit. Then use a pointed awl and work the bolt threads out of the head threads. It takes time but once it starts coming out it will just peel right out. Then run a 1/4-20 bottom tap into the hole to clean up the threads and install a new bolt.
This is how I would do it first pass if someone brought the head to me, and I couldn't get a grip point on the remaining screw material to coax it out. Even with 40 years of experience doing this, it's tough to drill a 1/4-20 dead center. There isn't much room for error here... if you mess the cylinder head, then you'll have to helicoil when you're done.
The weld-nut trick works great on bolts... 5/16, 3/8, 7/16 etc, but a machine screw (1/4-20) is a little tougher, especially given that the remaining material seems to be below the surface of the head at this point (drilled for an easy-out).
I also suspect the screw may have been too long and is bottomed in the blind hole. There may not be a void under it.
Lot of possibilities here.
Thread Starter
Burning Brakes
Joined: Sep 2006
Posts: 851
Likes: 10
From: Palm City, FL
Originally Posted by Tom454
This is how I would do it first pass if someone brought the head to me, and I couldn't get a grip point on the remaining screw material to coax it out. Even with 40 years of experience doing this, it's tough to drill a 1/4-20 dead center. There isn't much room for error here... if you mess the cylinder head, then you'll have to helicoil when you're done.
The weld-nut trick works great on bolts... 5/16, 3/8, 7/16 etc, but a machine screw (1/4-20) is a little tougher, especially given that the remaining material seems to be below the surface of the head at this point (drilled for an easy-out).
I also suspect the screw may have been too long and is bottomed in the blind hole. There may not be a void under it.
Lot of possibilities here.
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Melting Slicks
Joined: Mar 2002
Posts: 2,140
Likes: 7
From: Ohio
I have used all the methods above with good results. I have a new method that beats them all. I went to sears and bought a set of Craftsman left hand drills and bolt extractors. It comes in kit form for about $50. It may not work in your case but will work if you start on a virgin broken off screw. Some times the bolt comes spinning out while you are drilling. It came with instructions to just hit the drill on and off not steady drilling. If you can get the easy out out and you drilled in the center the left hand drill will still work.
Lyle
Lyle
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Using a punch to break that easy out is gonna be hard. Make sure you have a good place to lean, so you hand is steady and you have room to move the hammer. Ball peen hammer will probably give you the best oomph without using a 5lb sledge to tap it.
Thread Starter
Burning Brakes
Joined: Sep 2006
Posts: 851
Likes: 10
From: Palm City, FL
Originally Posted by Durango_boy
Using a punch to break that easy out is gonna be hard. Make sure you have a good place to lean, so you hand is steady and you have room to move the hammer. Ball peen hammer will probably give you the best oomph without using a 5lb sledge to tap it.
Instructor
Joined: Jan 2002
Posts: 243
Likes: 1
From: Knoxville TN
First punch the center of the bolt remaining or the ezout.
Take a small drill and patience, drill to about the length of bolt left,
then take a larger drill,
then a larger drill, upto to the next size ezout or before the bit gets close to the theads.
then the next size ezout or take a punch and a lot of penatrating oil and spin that bolt out,
then run a tap into the block.
This worked once for me on an old truck (had 3 bolts holding on a valve cover)
Good luck.
Take a small drill and patience, drill to about the length of bolt left,
then take a larger drill,
then a larger drill, upto to the next size ezout or before the bit gets close to the theads.
then the next size ezout or take a punch and a lot of penatrating oil and spin that bolt out,
then run a tap into the block.
This worked once for me on an old truck (had 3 bolts holding on a valve cover)
Good luck.
Melting Slicks
Joined: Feb 2003
Posts: 3,053
Likes: 4
St. Jude Donor '03,'11
Originally Posted by The_Dude
Sometimes, a reverse drill bit will turn them right out.
He's pretty much in dire straights.
Almost not worth the effort.
Le Mans Master
Joined: Jul 2005
Posts: 5,752
Likes: 4
From: Austin Texas
Originally Posted by turtlevette
you can't drill into an easy out. The bit is gonna go off center into the sofer material.
He's pretty much in dire straights.
Almost not worth the effort.
He's pretty much in dire straights.
Almost not worth the effort.
Melting Slicks
Joined: Feb 2003
Posts: 3,053
Likes: 4
St. Jude Donor '03,'11
Originally Posted by big_G
I always admire your positive attitude, turtlevette...
maybe a cutting torch or electric welder with cutting tool.
gunk it up with silicone and drive it until you get some aluminum heads.
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Originally Posted by turtlevette
Almost not worth the effort.
Originally Posted by turtlevette
Gunk it up with silicone and drive it until you get some aluminum heads.
