zbomb5610

so i was trying to tap the front 3 oil galley holes w/ a 1/4" -18 pipe tap and it worked great on two openings and then the third one it broke.

Here are some pics. What is the best way to get it out? I tried to use a screwdriver and a hammer to try to budge it since I feel it will turn out if it busts loose but then I broke the end of the flathead screwdriver in there as well as you can see in the bottom left of the pic.

What are the best methods?

Should I have something welded to the end of it like a bolt and then turn that out? or are their tap extractors that would work. keep in mind it is stuck in there pretty good and I did put a bunch of wd40 on there to try to loosen it up.

Any help is appreciated. I was planning on having the crank and the pistons in tonight but that isn't happening.

thanks

MikeGyver

If you do try to weld it, I would only consider TIG. MIG would probably just make a mess and give poor fusion.
You may also be able to ground it down and slowly melt it away with a cutting torch.

zbomb5610

thanks man, appreciate the help and ideas. Going to get the tap replaced tomorrow and then see what I can do.

grumpygreaseape

http://www.waltontools.com/products/extractr.htm there are things called broken tap extractors that may help you out if the broken end isnt too too wedged up into the casting material too badly. this is only one link for them. i have a set but the picture is a pain to post. just google broken tap extractor. you will find many of them.

zbomb5610

it is wedged in there pretty strong, i broke most of it off with a center tap but there is still a small piece left, wondering if i should just try to drill through that last piece, i don't think I will be able to break the little bit left in there.

Wild Willy

Hardened tool steel- probably as hard as any drill you have- the welding idea could work, if you have a talented welder- the heat would serve to loosen it, too-

We used to burn them out with a device in the shop that looked like a drill press with an arc welder electrode instead of a drill bit-

MachinistOne

Stop what you're doing and take it to the machine shop - it needs to be milled out with carbide end mills. You cannot touch a tap with drill bits or HSS end mills. The only other option is to try and break it into little pieces, it should be very brittle...which is why it's able to be so sharp.

FYI, in the future - those front oil galley's have a mis-matched step which will break a tap every-time, you need to use a face ground tap so that you don't go in as far.

MachinistOne

Sounds like an ancient EDM machine - we have one of those(EDM) and that would be an option to remove them too.

Wild Willy

That's the one! Haven't been in the machine shop in 20 years- former apprentice- still have my tools, dial indicators, mics- the skills have been invaluable over the years- when I went into civil I could read blueprints easily-

This country needs more jobs like that, but we need to get back to manufacturing stuff, first-

grumpygreaseape

i would do my best to remove that pesky screwdriver tip first. drill it and use a small punch to defeat the rest of the tip. then you can fit all 4 extractor tips into the broken tap and remove it. just take your time and be careful.

zbomb5610

just want to say thanks to everyone, I actually already had that scewdriver tip out, then used a center punch to beat the crap out of the tap breaking it into small pieces. then I punched out the remaining small bit through the backside w/ a 3/8" x 36" metal rod.

I was able to retap those 3 front oil galley holes no problem. Going to finish cleaning the block on wednesday, clean my heads, and then fri/sat/sun will be putting the motor together.

again, I appreciate the help, thanks.

grumpygreaseape

victory-you won. good job.