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I have a set of double hump 194/160 heads with new hardened seats. Engine sucked more coolant than fuel. Machine shop wouldn't do any thing, said fill it with Barrs Leak - Not Me. I think all double hump head castings from 62 to 67 were the same except the X versions. Someone correct me if I am wrong. If I can get to them, I might try drilling until I hit the water jacket and report back unless someone beats me too it. I really don't think you will pop thru with less than 1" of depth. Robert or one of the professionals that do head work every day might be able to confirm my theory. I asked my wife and for the first time in 54 years she didn't have an answer.
. I sometimes "what if" things to extreme, guess it's part of my schooling from long ago. The bits and taps are scheduled to arrive later today and I'll have a better understanding when I start to drill. Hopefully just enough to get some threads.
Thanks,
John
A thought on alignment if you are drilling by hand. Trash the idea if you don't like it.
Assuming you have the aluminum valve covers, the holes are just slightly bigger than 1/4", not even 1/64" bigger I.D. on the set I have. I would cut a 1" long piece of 1/4" O.D.. tubing (brake line or copper or etc.) to use as a guide thru the hole. Run your #7 or 13/64 bit thru the tubing to make it the correct size I.D.
Bolt the valve cover down securely and drill thru the hole with the bit and tubing spacer. This will keep you centered and confine the chips within the hole of the valve cover and also protect the valve cover hole from damage from the bit. You can fill the hole in the valve cover with grease to help retain the metal chips.
Now you have me doing the overthinking!!
Ron
There is a lot of play in those valve covers. I’ve had better luck center punching and then start a 3/32 bit, drill and aim straight. Step up to whatever size for the EZ out. Hopefully it will extract easily. Clean it throughly and apply a release agent to a bolt and screw in the bolt. Apply JB Weld to the cracks and apply a clamp. Let it setup well then remove the bolt. Chase the threads. That’s what I would do.
No engineering training, architect studies, worked as lawn keeper, farm hand, laborer, soldier (good at dodging bullets), draftsman, surveyor, operator, civil engineer, estimator, TV repair, plant engineer, cost engineer, Production Foreman, QC Manager, Bridge Superintendent, Project Manager, Electrical / Mechanical Planner, etc., etc., etc. Guess they could never find anything I was good at.
Final job: Retarded = lawn keeper / landscaper, Maytag repair man (and all other appliances) , door man (for dog), chauffer (for Ms Mary & Dog), snow removal, equipment maintenance, IT repair man / consultant (wife's tablets, phones, TVs, etc.), home repair man, financial manager (not much work for $25 or so), liar (YOU LOOK 20 YEARS OLD - got to keep them happy), shade tree mechanic wrenching her classics. Still nothing I excel at except:.
Being RETARDED, I have a master's degree in it with a minor in BUBBA engineering.
Ron
Bob,
Thanks, I ordered some left handed bits this morning.
Appreciate the suggestion,
John
I think I missed the part in your original post about there still being a portion of the original broken bolt in the hole. In this case, the suggestion of using a left hand drill bit is good. I have done this many times (actually did one last week). The important thing is to start a pilot hole in the CENTER of the broken bolt and drill STRAIGHT. After getting a pilot hole, use a 3/16 left hand drill bit. Go slow and many times the bit will extract the broken bolt.
Wanted to confirm the use of the valve cover and spacer for guidance. The bolt hole in this valve cover measures 0.255" I.D. The brake tubing is 0.25" O.D. and the bit I am showing is 3/16" (0.1875") O.D. So, if you choose to do this for a guide, verify your valve cover has the same hole diameter or adjust the spacer accordingly. Just a BUBBA idea.
Not sure if this is an original or aftermarket valve cover. Might have different hole sizes????????????
I shake worse than leaves on the trees in a 50 mph wind, so I have to cheat.
Sorry I'm late here. My friend Tim has a business here in Huntsville serving all the dealerships and shops going around extracting broken bolts just like this all day long. His father taught him how to weld his tools onto the end of broken bolts just like this and spin them out. It's amazing. I'd guess the heat from weld helps. Your area may have a similar service. Then install Keensert or Helicoil.
If you are going to drill and re-tap, start with a self starting tap and use it until it bottoms out then remove that tap and replace it with a bottoming tap. That way you’ll have threads for 90% depth.
Last edited by vetsvette2002; 10-18-2022 at 02:00 PM.
The three taps and drill bits arrived from MSC this afternoon! Pretty quick delivery. While they are based in Illinois, it helps that MSC has a huge warehouse in PA.
I started to prep the OR by moving over the Master Cylinder and putting in a barrier to prevent errant metal shavings contaminating the head. But curses! My wife arranged a dinner date with another couple tonight so I'll have to lay down the scalpel until tomorrow (unless I wave off the wine and feign an illness at dinner).
More to follow tomorrow, but here's a couple of snapshots so far (Sorry about the size of the pictures, I was in a hurry).
Thanks to all the comments here, my confidence is on the rise..
I took the bolt out that holds down the brake lines Wrapped the MC and tied it off to allow a straight on angle. A slice of carboard will make a good shavings stop. I'll probably lay in a line of grease to hold it and catch any shavings.
I'm a bit fanatical about preventing anything from falling into the engine. I'd lay down some wide (double wide?) gaff tape on the cardboard that flops over the edge of the head as well - working as a kind of solid net to catch every shaving. Then, like a surgical blanket, you can make a hole in the tape just where the business end of the work is happening. The grease can still be used on top of the tape. I'd probably remove the dipstick and tape over the tube, and tape over the booster for the MC as well.
Overkill? Yeah, probably, but only 2 minutes worth for insurance against my own drfitin', daydreamin' mind doin' something dumb. e.g. when I walnut blasted the intake ports and valves on the Audi (in car, and the fastest/bestest/easiest way to remove carbon on the newer DI engines) the blaster wand slipped out of the specialty tool on the cylinder head and shells went flyin' everywhere - I mean everywhere. Luckily I had everything covered, taped over, shop towels stuffed in, etc. Otherwise the alternator, oil filter mount (which is on top of the head), open ended hoses, etc. would have all needed a thorough cleaning. Thanks to over-engineering the gig, all I needed for clean up was compressed air and a shop-vac.
Last night's dinner was well worth it and I decided to wait until this morning to get back to the repair. It started out well. I did some additional covering as suggested. I didn't want to cover up the engine too much because I didn't want to lose the angle references to the head when I'm drilling. (I'm drilling free hand so I needed visual clues to make sure I was drilling perpendicular to the surface).
I started drilling a pilot hole with a drill bit a little smaller than the final tapping-size bit. It worked for a little while. I think I'm pretty much dead center to the original hole. However, progress soon slowed to a crawl. I noticed that at a low drill speed, the drill was vibrating a little. I checked a couple of times in the hole and it appears there is something hard lodged in the hole. The pictures aren't that good, but you might be able to make out a round, raised point in the hole (See third picture). I think I ran into an old broken-off drill bit. The vibration seemed to be the two flutes on the drill bit smacking the hard object lodged in the hole.
If this is an old drill bit, is there a way to remove it? I tried poking at it with a pointy pick but no-go. It's solidly lodged in there. If there was some magical cutting drill bit that can cut through other drill bits, I'm all ears, but I doubt that even if it exists, I could keep it centered on the top of the lodged bit (the tip of the lodged bit is now convex).
The going-in thought this morning was to drill down deeper into the head in order to tap some new threads. Given I've hit the drill bit, I can't go down any deeper. Maybe it's time to be thinking installing a heli-coil?
Thanks,
John
Additional covering, masking tape on dipstick tube, and grease. A little oil added when drilling See the small "bump" in the center of the hole? It's hard to make out that it is a little taller and I'm just grinding out stuff around it.
I feel your pain. Most likely the previous owner snapped a bolt off in the head and tried to remove it with an Easy Out. The Easy Out may have snapped off. I did this when repairing a water pump on a Nissan engine. The bolt was buried deep in the engine. I snapped off the Easy Out. My dad was a machinist. He made a bushing that allowed me to drill a hole dead center on the Easy Out. We had to use a carbide bit. We ended up drilling through the Easy Out and tapping and threading the hole with an SAE tap and bolt. The repair lasted the life of the car. Hope this helps. Jerry
Looks like a previous mechanic laid down a rake for you to step on. I don't like those guys and hope to never be one. This extra goody in the bolt hole, for me, would require removing the head for some professional intervention at the machine shop, especially if it is a correct head. And, at that point, if I didn't have history on the heads, I'd take them both for a hot dip, new valves, seats, guides, seals, springs, retainers and cotters - the full Monty. A couple of c-notes plus parts would provide some piece of mind. If you don't take the time to do it right, you will find the time to do it twice.
Can't tell much from the photo, but if you have a center punch, try to put a punch mark in that "object". If the center punch won't put a punch mark in it, it is most likely a drill bit or easy out broken off in there. They can be drilled with carbide drills, but it would be pretty difficult doing it with a hand drill. I've done it a few times, but was doing it on a milling machine. I know it's not what you want to hear, but it may be time to take the head to a machine shop.
I can only think of a stud welder to shoot a 3/16" stud to the broken 'what ever it is'. But If it is an extractor (easy out), I don't know the metallurgy to determine what would be compatible. I have taken a chisel and broken out an extractor in bits and pieces, but not in a 1/4" hole. Extractors and drills are extremely brittle. I think you are down to a diamond tip drill bit or maybe carbide.
Are you a welder or have access to a welder with a welding machine? A wild thought is to put a 1/4" copper tube in the hole to the top of the broken bolt and then arc weld a 3/32" dia. ER309 rod to it and then try to back it out with the welding rod. Problem is, the weld material may make it even more challenging to remove.
All these are great ideas! I do have a welder, but with my skill set, I'm very dangerous.
As you all suspect, there's something really hard stuck in the hole. Taking it to a machine shop would be the best, most permanent fix. However, I'm not that excited about tearing down the top right now. Everything has a habit of snowballing and before you know it, I'll wind up pulling the body off the frame. At my stage is life, I want to drive more/work less.
That said, I gave up on trying to drill further down. I proceeded to see if I could drill out what I had and install a heli-coil. I followed the procedure first with the correct drill bit size, then got out the tap. Unfortunately, as I was easing the tap into the hole, the crack in the side of the hole broke out. Yep, a piece of side wall about 3/8" in diameter came off. Bummer.
Since threading the hole isn't going to work, I decided to cement the heli-coil in with JB Weld and see how that works. I cleaned out the area numerous times with q-tips, lacquer thinner, acetone, and anything I had handy. I got some of the slow setting JB Weld mixed with metal, advertised for 5000psi and 500 degrees. I'll apply it to the sides of the hole, insert the heli-coil, slather a little on the outside where the cracked piece of metal was, and let it sit 24 hours.
I'll have to watch how I put the JB Weld on, because in past experiences, it obeys the laws of gravity and has a tendency to flow down hill. With the top of the head being angled, I'll have to build a little dam around it and keep everything in place.
This thing, while interesting is starting to test my patience, but you all have been great support. Again, I thank you for your ideas and your willingness to help.
John Overhead shot of the heli-coil fitted in the hole (with the cracked out side) I thought about sticking the cracked out piece back in for support, but thought if there's a failure, I'd rather have JB Weld floating around rather than a chunk of cast iron.
Have you called any dealerships or auto repair shops to ask if there's someone who removes broken studs or bolts in your area. Your problem is common and my friend Tim drives all over our midsize city all day long fixing problems like yours for mechanics. But it involves very skilled warming/welding techniques. Since the side is broken out I wouldn't use a helicoil. Look up Keensert or equivalent threaded insert. An insert that's not just a wound wire. Can almost guarantee JB is a waste of time.
10-17-2022, 09:11 PM
. I sometimes "what if" things to extreme, guess it's part of my schooling from long ago. The bits and taps are scheduled to arrive later today and I'll have a better understanding when I start to drill. Hopefully just enough to get some threads.
