ok I was down to removing the last drain plug before heading to the machinist. Plug wouldn't budge after soaking overnite with penetrating oil, punching with a hammer and applying heat, end up shearing the hex head off. Drilled the plug and tried to use a bolt extractor but this just expanded the plug until it cracked the boss the plug screws into. Is this able to be welded and repaired or is it junk?

You could probably just braze up the area to put back what material was broken off of the block. This sort of repair is a permanent fix. The only problem that I see is that it might be tough to re tap the pipe threads. While the brass and cast iron will machine very easily many times right around the area that's been repaired you can end up with some carbides which are very hard. Some careful work with a die grinder might remove them easy enough however and once the hole is rethreaded it would be as good as new.

would it get you past the crack before you ran out of boss ?

this is the little 1/4-5/16 plug that drains water outta the block ?

If I had to drill bigger than about 1/2 inch I would braze or weld

"rustite" is way tougher than anything loctite has come out with yet ... It keeps getting stronger as the years go by !

I sometimes try to get those plugs out but if they put up a fight I think about drilling and tapping a new hole for a water drain

Almost without exception the easiest way I've found to remove a pipe plug from a block is to take a torch and heat the plug red hot. Heat only the plug and not the block. Let it cool/shrink. Nine times out of ten it'll then be loose in the hole and only finger tight. A couple of heatings may be required.

around the plug or whatever it is , not using any real force but just tapping with a ball peen hammer

when you get the plug red hot....press the candle(parifin only) it will wick a small amount into the threads..might have to do this a couple times. But it works like a charm. The other way is to drill the Bastard out large enough and then get western on it with a cold chisle...

oxyacetylene torch to get the heat into it but just to a dull red or a little beyond dull red and then let it cool. A couple of heat/cool cycles. Don't heat it to a blast furnace red heat or white hot! You don't want to crack an otherwise good block for the sake of a 2 cent snotty stubborn plug that probably doesn't need to come out in the first place. The plug is probably very soft after this hot/cold procedure so you need to get a good purchase on it with whatever worn out tool you are using. You'll probably have to go buy something new for this job. 30% chance you'll be drilling next. Drill a small hole on center thru the plug then the biggest hole you can get thru it without hitting the casting threads, good luck, another trip to Lowes for drills. Take a slender and sharp angular file to the resulting hole. You'll have to buy a couple of files cause all those files in your tool box are beaten up, dull and broken off. File 3 or 4 notches to the root of plug threads equally spaced around the inside of the hole then use a slender and sharp punch to collapse the 1/4 shells inward. You'll have to buy these punches too because... well you know why. This takes some practice. There's probably faster and less tedious ways if you have access to more elaborate tools but I 've actually done this many times. Patience is a virtue that will serve you well. 10% chance you'll be drilling and tapping for next size plug (more tools will be needed) or plugging and brazing up the ugliest hole you've ever seen and wishing you hadn't tried to get the plug out in the first place just because it was there and you thought it needed to come out.

When they freeze up, I just leave them alone! Especially when I'm under the car, tryin to drain the block. I don't know what Ford was thinking about, when the put those plugs in with such a small head to get a wrench on.

I had the same problem in my last build, a low mileage 4 bolt main block. I used several different "rust busters" and finally resorted to heat. I'm glad I got them out. When I flushed the water jackets I got a lot of casting sand and debris which didn't come out from an earlier pressure flush/wash. I put brass petcocks back in using Radiator Specialties Tite-Seal #55. It's a non-hardening liquid that is the best water sealer I've ever used. I also used it to seal a "loose" fitting heater tube that was seeping after I fired the engine. An old plumber turned me on to the Tite-Seal #55. It works on gasoline and oil fittings too. I used it to get my Holley center hung float bowl fittings to seal. The flares wouldn't seal to the fittings and I used a very fine bead of the Tite-Seal and they stopped immediately. You can find Tite-Seal #55 in the plumbing dept of most hardware stores. It beats the heck out of teflon tape.

i used a 3/8" drive allen socket on the plug backwards so the 3/8 square was on the plug, then a socket and long bar on the allen. much heat was involved also. they were still a bear and i had to work them loose/tight and lube until they let go.

the method of heating the plug red and letting it cool is probably the easiest/most reliable. MAPP gas runs hotter than propane.

if the head of the plug rounds off, welding a bolt or not onto the remains of the plug will also put a lot of heat into the part, usually enough to let it turn out easily.

there's also another trick involving a candle, the idea is to sweat candle wax into the threads. many say it works great, i've never bothered with the wax.





"Enlightened statesmen will not always be at the helm" ~ James Madison

i know its to late for this now but what works very well for me is to drill a hole threw the midle of the plug, or bolt get some 3/32" stainles welding rod and weld the hole all the way back up, then at the top of the hole slowly build up with weld intel you can weld a nut to it, let it cool, the weld will cause it to shrink and it will spin rite out no problem, you need to run your welder on a very low temp so you dont under cut out of the hole, i use this prosses all the time at work on bolt sizes from 3/8" up and it always works, you may want to practice a little before you try it, it take some welding skill but it realy works.

i added weld material to a #6 or 8? size screw on a predator carb, whatever size the screws are for the bowl cover panel.

"Enlightened statesmen will not always be at the helm" ~ James Madison

the small ones are fun, 3/8" is about the smallest ive done when i have to drill threw them and weld the hole back up frome the inside, but with that stainles rod you can weld to a bolt broken off in a hole down inside as far as an inch or so and the flux will run out to the threads and protect them, just keep the rod in the midle of the hole and built it up tell you can weld a nut to it.

Thanks for the quick responses everyone.

Joe, yeah the crack goes right to the outside of the boss and down about an inch so it will have to be braised.

Dave I vaguely remember heating just the plug on the last block I stripped down and it worked well. For whatever reason my feeble mind forgot about that episode and I heated the block this time instead. Oh well, live and learn.

I spoke to the shop today and he said it could be repaired and would have to be pressure tested and kept suggesting I get another block, I got the feeling he didn't want to attempt the repair I'll drop it round to him on friday morning and see what he thinks. If he's not confident I'll go somewhere else.

70TooMach you don't happen to have a photo of the petcocks you installed do you, sounds like a good idea. How do they go for leaking on a running engine?

Darren, you use a regular radiator drain petcock. Any Napa store or good well supplied auto parts store usually carries them. I think I bought two of them from Summit, but they don't list them anymore.
Here's a couple of links that shows a picture of what they look like.

http://www.jegs.com/webapp/wcs/stores/servlet/KeywordSearchCmd?storeId=10001&catalogId=10002&langId=-1&N=0&Ntt=Brass+Petcock&Ntk=all&Nty=1&D=Brass+Petcock&Ntx=mode%2Bmatchpartial&Dx=mode%2Bmatchpartial&searchTerm=Brass+Petcock

http://www.ecklers.com/product.asp?pf_id=51003&dept_id=1255

As far as leaking, these used to be installed on every engine block back in the 30's 40's and 50's when they had to service cooling systems on an annual basis, because antifreeze and coolant weren't as stable/corrisive chemically as now. I have petcocks on all of my vehicles engine blocks and radiators. If you live in a part of the country that freezes hard in the winter and you don't want to keep antifreeze in the system, just open the petcocks take the radiator cap off and let it draing. They are at the lowest point of the block in the cooling system on a Cleveland.

were you planning on having the block baked clean? i don't think many shops do hot tanking anymore, but what i'm getting at is; if you can get the internal surface clean, maybe you can do an epoxy cover patch on the inside after the braze, like a double repair for good luck. the drain hole may not be a drain hole any more though, small price to pay to save a block.

also possible that you could do a very short fill with epoxy with a rubber plug in place, remove the plug later and run a tap through the threads and still have a drain.

there is that ceramic sealer product too, i don't know if it'll work over/through a failed braze repair or not?

and the copperseal/alumaseal products. it could be as simple as using a radiator stop leak product after you fire it up.

is the crack upwards from the drain hole? it'd really be slick to do the braze repair by heating from the outside and sweating the rod through the crack from the inside. seeing the bronze sweat though the crack would give a good feeling of success.

standard procedure is to drill a small hole at the end of the crack to stop it, not sure if that's a good idea here or not?

"Enlightened statesmen will not always be at the helm" ~ James Madison

maybee drill a small hole at the end of the crack like tinman sudjested, clean the block then do a short fill with hard block, then add the stop leak if needed.

and an experienced welder would make short work of the repair with no adverse affects to the geometric integrity at all. It's not a critical area for cyl wall support or high pressures or anything to worry about.

Find a welder who knows how to handle cast. He won;t be afraid of it at all and neither should you.

I also use brass petcocks to replace those shitty steel square head drain plugs. First, brass will never corrode in cast, second the thumbscrew makes for easy drainage, and lastly, you can get them in either the standard 1/4" pipe thread that is the stock size or drill and tap the damaged area to 3/8" pipe and use a larger petcock.

They are readily available at any marine dealer. Steel doesn't play well with salt water. Not real well with anti-freeze either after almost 40 yrs of service but brass will always come out without damaging the block.

Looks like I'm spending tommorrow shopping for petcocks and a decent welding shop.

wright tools 4312

http://www.waresdirect.com/products/Commercial-Products/Wright-Tool/12-Dr253404

I used it yday and pulled every one of those plugs on greasy blocks , on rusty blocks an old powell wrench that is also 3/8 squaredrive worked a little better . the powell is probably no longer available its Olllllld

i think my 'system' is even better because that's an 8 point socket, mine's a 4 point, no chance of rounding a previously damaged square head, then i use a 6 point on the allen bit, again no chance of damage.

i have a few or more 8 pointers somewhere, just where is the question. my 6 pointers i can find...

i figure by the time i'm DONE, i'll have all my tools in my new boxes and organized.

"Enlightened statesmen will not always be at the helm" ~ James Madison

although it has 8 points it's asymetrical 4 of the points are really small , the big part of the opening is what fits the plug. that socket has not failed yet on a greasy block . if rust is an issue I use a forged steel four point wrench

i thought the end showing would be the 1/2 drive end?

so if the 3/8 end is also asymetrical, it's like a 'flank drive' and pretty much reversible? it could go 3/8" drive 1/2" 8 point too

"Enlightened statesmen will not always be at the helm" ~ James Madison

My D2 4-bolt block had allen head plugs in the block? I twisted a 3/8 socket head allen into a nice spiral before I used my Mapp gas torch on the plug. My 1970 DOVE block has the allen plugs too.

The one I fubared is a regular 6 point hex head plug, not square head, not allen head. I just used a regular 6 point socket. These are the water jacket drain plugs near the bottom of the block, one on each side. I've got 4 clevo's here and they are all hex head.

my virgin 4 bolt block had the square heads, they were a real bugger after being in there 37 years. i had to heat and use a square socket to get them out.

the 1/2 end is a plain square that you put a ratchet into , the other side has a 3/8 inch wXh square in it . there is also a smaller square situated at a 90* angle to the "big" square for "hard cases" I guess . This is not an adaptor or anything I have them from 5/16 - 1+ inches

You can get a 3/8-3/8 adaptor socket which just has two female ends , I have one and it wont really work cause the holes somewhat bigger than a true .375 so you can swap it on and off a ratchet quickly .

mine are not the same as yours, they are 4 point sockets, but do the job just the same. i use them at work on quare head set screws.