Cylinder Head Bolt Broke

[The Mighty Gryphon]

Removing cylinder head to replace valve stem seals today.  Everything going ok until I tried to break loose the last bolt in the bottom rear of the head.  Instead of breaking loose, the damn thing broke off, looks like the threads rusted into the block. 

So now I have the f-ing thing with 1 thread above the block.  Last thing I want to do now is pull the f-ing engine to take it to a machine shop.  Can you tell I'm pissed?

Are these bolts hardened?  Can they be drilled?  I have a fixture that can center the bit, but will I be wasting my time trying to drill a hardened bolt?  Am soaking with penetrating oil, and will probably give it a week before I try removal.  Any tips from someone who's been there and done that?

[Scud]

Yeah, pisser... good idea to step away for a bit.

You can practice drilling on the part that broke off - just secure it in a vise or something. That is the best way to see if your drill bit will work.

Before you drill into the stuck portion of the bolt, give it a few taps with a hammer (via a centerpunch) to both center your drill bit and try to knock the frozen part of the threads free. Then I assume you will use an easy-out.

Best of luck.

BTW - which motorcycle are you working on?

[Martin]

Before you try to remove the bolt try heating the block around the bolt with a hot air gun or carefully with a torch. Once it is hot spray with a good penetrating oil. WARNING let it cool a bit before spraying you don't want it to catch fire or explode. Do this a couple of times and let soak over night. When I worked in Bass Strait (Esso Oil Platforms ) we had some oils  .One was a penetrating oil called LPS 1, 2 or 3 can't remember what  number it was. It was made in the US and was really good especially in adverse conditions and given enough time & heat it would work 90% of the time. I believe the bolts will be hardened, if so you might be able to weld another bolt to what remains .But you would need to protect the block with heat proof putty or maybe drill a hole in a thin sheet of steel to go around the hole to protect the block while you weld .I used to work with an old German engineer who was a master at doing this, I have done it a few times but only on cast iron blocks. The last resort is to load the bike on a trailer and take it to a place that does spark erosion.
Hope this helps Martin

[Martin]

Another Option.Forgot to tell you try can try drilling first but you  need to first create a flat spot, and centre punch it.Because you only have a small bit protruding this will stop use from using the weld on method. Start with a small drill use really good HSS drills not Chinese and progressively use larger sizes. Drill at a very slow speed apply plenty of coolant make sure you are drilling square use a spotter to make sure you are square , and do not over heat the drill. If you are going to use ezy outs drill to the recommended size, heat and apply penetrating oil a few times leave over night to soak, build a little reservoir out of plasticine or something similar. You need to be extremely careful when using Ezy outs if you break them you will have to use spark erosion as nothing I know of will drill them out.
Good Luck Martin

[koapono]

the BEST penetrating fluid i have ever used is a 50/50 mix of acetone and dex/merc tranny fluid............works better than any of those widely available products.
G'luck

[Elipten]

If using LPS you want number 1 for this job. Best liber ants around. I think I bought of Amazon 2 years ago

[drut]

the BEST penetrating fluid i have ever used is a 50/50 mix of acetone and dex/merc tranny fluid............works better than any of those widely available products.
G'luck

Noted on another forum and used by me with some success since.

April 2007 "Machinist's Workshop" magazine comparison
test.

*They arranged a subjective test of all the popular penetrants with
the control being the torque required to remove the nut from a
"scientifically rusted" environment.


*Penetrating oil ..... Average load*

None ..................... 516 pounds
WD-40 .................. 238 pounds
PB Blaster ............. 214 pounds
Liquid Wrench ..... 127 pounds
Kano Kroil ............ 106 pounds
ATF-Acetone mix....53 pounds

*The ATF-Acetone mix was a "home brew" mix of 50 - 50 automatic transmission
fluid and acetone.*
*Note the "home brew" was better than any commercial product in this one
particular test. Our local machinist group mixed up a batch and we all now
use it with equally good results. Note also that "Liquid Wrench" is about
as good as "Kroil" for about 20% of the price.

[Laitch]

There's so much sound advice in this thread, I think I'll add some dubious advice for equanimity.

The first step —and it's never too late for this—is to blame this problem on anyone who is nearby then increase the blame globally.

After that comes heat and oil. I'm not as circumspect as Martin is when I get into desperate straits. I'd wipe the oil out of that head then heat that bolt with a heat gun until it was hot enough to smoke penetrant oil. I'd drench it with the oil until it stopped smoking—or until I passed out from smoke inhalation. As far as penetrant is concerned, I've had unqualified success with WD-40, Liquid Wrench and Ellipten's LPS 1. All these products emit a glorious white smoke when they hit a heated bolt. Kaopono's blend might be fun and Drut's research certainly supports it but I never seem to have acetone when I need it. I intend to make a serious effort to beat the meth chemists to it. Today!

After the smoke cleared and I regained consciousness, I'd get to work after a cup of tea and about 30 minutes or so while heat is still working its magic. I'd apply the removal steps recommended by Martin; my choice would be a left-hand drill bit. Drilling down with the left-hand bit will create vibrations that may loosen the bolt and eventually free it so it could be backed out with the bit or easy-out at low speed. If you use an easy-out, periodically tapping it then sharply torquing it may work but if you break it you'll compound your task.

The good news is that if you accurately centered the bit but the bolt doesn't free up after repeated attempts, you can drill with progressively larger bits until the original material is so thin that it may possibly be broken apart with a pick then removed with the pick, rags, oil, air, suction or an aardvark trained for the purpose.

It only took me a couple of broken bolts early on to teach me that application of heat and penetrant is the first step followed by loosening with alternating small increments of anti-clockwise and clockwise torque until the loosening rotation direction prevails.

When the correct bits and tools are available, all it takes is nerves of steel and a calm disposition. :yow

Of course, if I had the money, time, a trusted machinist and humility, I'd get the machinist to do it and I'd devote the interim to something enjoyable.

[kris]

Gryph,
Sorry for your dilemna. Shit....why is it almost always the last bolt??? Just when you think you're done? I'm always a fan of heat and tapping, along with the oils. Martin, some great stuff there. Sounds like you're pretty experienced with it.

If it doesn't work you can always borrow a 30 odd six and shoot the damn bike!

[Martin]

Any method suggested can work, but the key is patience, go slow and think about it. The welding method if you decide to go down that path, should be a lot better these days, we had to use arc welding .These days I would go TIG first. If you know a really good TIG welder this would be the best, followed by MIG. I would not use arc these days. You need to V the bolt that you weld onto the broken bolt, do the weld in short bursts, little tacks and let it cool between tacks. We used to have this putty in a large tin that insulated the coated material, unfortunately that was in the mid 70s and I can't remember the name. Try a welding workshop it was good stuff and you could reuse it. Another not so drastic way is to use the heat and cool method with dry ice. Again wih penetrating oil a plasticine reservoir and overnight soak. If you can loosen the remains it might also be possible, to cut a slot with a dremmel disc. Its a pity you live so far a way, I could ride over and give you a hand, but I can't hold my breath that long. I would probably freeze when I got there ,I only own two light jumpers. If I think of anything else I will contact. If you have anybody local that can help make a decision, two heads can be better than one. Weigh up all your options before you commit to any method.
Good Luck Martin

[The Mighty Gryphon]

Martin and the rest, especially Martin, thanks for the suggestions.  After a night to sleep on it, I am in a bit better mood, but still not ready to do any machine work.  Scud, it's the white one in my avatar.  111,000 miles and burning oil.  Needs valve seals.

For starters, I am going to continue soaking with Liquid Wrench.  Will try the heat thing heating with a propane torch.  Fortunately, it is on the corner so the heat won't get too many places where is shouldn't be.  I probably won't be reassembling until some time next week, so I will use the time to soak.  Of course, the the bolt is on a vertical surface so I can't easily leave a puddle of penetrating oil to leisurely soak into the joint.

When the time comes I am going to try this little gem to center the bit.  The strategy here is to drill out the solid part of the screw and then remove the threads by pulling them out as a thin strip.  Nice thing about it is that it centers and orients the bit perpendicular to the surface.



Martin, great idea with checking the drill bit on the broken bolt.  So obvious, which is why it would have never occurred to me.  The heat on the broken threads sounds good, too.  Will be updating next week when I go after it.   Hoping I don't have to Helicoil it.

[Martin]

Gryph I was running late this morning when I made the suggestion about cutting a slot with a Dremmel. I failed to add than you can then use an impact screwdriver on the bolt, after heating and soaking.  I don't know whether you understood my reference to plasticine, it's sort of a kid's reusable modelling material, a bit like Play Doh only it's slightly oily. Its really good to make little funnels to lubricate things like cables, and to make little dams to hold penetrating oil while it soaks over night. When you have finished with it I just wring out the excess oil and put it back in an air tight tub. Probably available in toy stores or ebay.
Regards Martin

[Martin]

Gryph it was Scud who made the suggestion about checking the hardness on the old broken bolt. Credit goes to Scud.
Regards Martin

[The Mighty Gryphon]

Was thinking about the Plasticine today, but didn't think it would stick to the block with the penetrating oil.  Will pick some up tomorrow and give it a try.  Will soak as long as possible before attempting to remove.  Valve spring compressor is coming next week so I still have 5-6 days to soak. 

[jakgieger]

Many times on the farm we deal with this situation...left hand bit or weld a nut on the stub...try welding first.  Yes be wary of the heat.  Weld fast, on the inside of the nut, then cool with penetrating fluid, heat will "draw" it in.  Let it cool then cross your fingers.  If you get it to move WORK IT BACK AND FORTH SLOWLY and take it out.  Seems to me this situation was discussed in Zen and the Art of Motorcycle Maintenance .  Good luck

[Martin]

Jack I do like your method of using a nut & welding on the inside. I have always used a bolt mainly because that was the way I was taught and I had access to the heat putty. But your way does seem better in certain cases. Never to late for an old dog to learn new tricks.
Regards Martin.

[Martin]

For anybody interested if you go to youtube & type in Viper Wet Rag Reusable Heat Blocking Putty. They have a really good demo video on what it is capable of doing and for what it does is probably cheap. When I first used it the old German Engineer covered his hand in it then ran an Oxy torch over it . At the time I was really impressed. It is really worth a look.
Regards Martin

[jakgieger]

Martin, your idea (for welding) will provide a stronger weld,  but we have "one" thread exposed.  Not enough length to accomplish safely.  The nut idea weld is weaker, but will put heat exactly where it is needed, ON THE BOLT!  The man who taught me would usually attempt to turn the nut while still hot. ONLY A LITTLE BIT TO TEST YOUR WELD AND MAKE SURE THE BOLT WAS FREE.  THEN LET IT COOL AND TURN IT OUT.  We have different metals here that have seized.   The only other possibility is a hand powered  impact screw driver, but the length of bolt remaining will not allow for a "good" groove to be cut.  Several years ago, in restoring an R60/5 I had something similar in trying to free the motor.  Aluminum piston and steel sleeve=major pain in the ass.  Tried everything ...penetrant, heat, patience, cussing, wooden mallets.  Eventually my threshold of tolerance was exceeded :dunno2:.  I put a chisel through the top of the piston, broke it free immediately :hehehe.

[The Mighty Gryphon]

A bit of an update:  The holes are counterbored in the block, and on the broken bolt, there is a lot of rust packed in the counterbore around the broken part of the bolt.  I have been soaking it with penetrating oil for two days now amd have been able to dig out a lot of the crap that was in there.  Still putting on the penetrating oil, and hope to try the impact driver, possibly on Monday. 

I am hoping that the rust doesn't go in much further than 2-3 threads and that it will break loose without the crap in the counterbore.  I am basing this on the fact that there was little rust on the part of the bolt that was above the break.  Seems like the water was collecting in the counterbore.

I know the welding technique works and have used it on factory machines, but I have no access to a MIG welder.  Only heat source is a propane torch that barely heats the block around the bolt.

I suspect that the problem is a gap that is not effectively sealed by the head gasket between the head and the block at this lower corner that allows for ingress of water to the bolt.  This is the only bolt I can see where this path exists and is probably the reason for the rust.  On reassembly I plan on giving this bolt a very good coating of anti-seize all the way up to the head, as well as the inside of the counterbore even though it is aluminum.

[Laitch]

I suggest you substitute a small Mapp gas tank for the propane tank on that torch and try again. It should get plenty hot enough.

[Laitch]

I think you're going to be able to drill that thing out of there, Gryph, one way or the other and get on with your project, rust or no rust.

[The Mighty Gryphon]

Re the MAPP gas.  Been using it.  Lotta heat sink in the neighborhood.

[drut]

 A few observations,probably not helpful,from having been in your position a few times over the years

Aluminium alloy soaks up/dissapates heat like you would not believe and if you step up heat to oxy acetylene melts with little warning.
"Easy outs" are the work of the devil:by their nature they try to expand bolts & are brittle/not too difficult to snap if you are not experienced in there use leading to a harder job again.
These drill bits http://www.wlfuller.com/html/drills_for_hardened_steel.html work well but only on really hard steel such as easy outs & truly well hardened bolts.
The welding method works best on bolts into cast iron but will work well on aluminium if there is enough protusion:I have sucessfully used it to remove broken exhaust manifold studs from aluminium heads by mig welding(innerof) nuts to studs but tig welding would be my first choice if available.
The heat sink paste already mentioned works really well:I and many others used it to good effect to minimise the heat spread from oxy acetylene welding before mig/tig welding became commonplace.

[Laitch]

All right, Gryph, how about revealing how the seized and decapitated head bolt was remedied?

[The Mighty Gryphon]

Update:  Went in with the Quik Center.  Nice perfectly centered pilot hole.  Enlarged hole, but didn't have 8.5mm bit for final drilling.  Tried to use easy out, but the sucker is froze solid in there. 

Looks like it'll be a few more days before this gets resolved.