busted brass!!

[Marty Levenson]

Hello! I need some advice....!

I want to mount my mechanical oil pressure gauge directly on the block. When i went to disconnect the 4" brass nipple projecting from the oil port (the one just behind the flange of the flywheel cover - port side) it snapped off flush with the block. Arggggh!

I spent an hour first trying to "tap it around" to get it off, with no luck. It seemed that every time I tried, the bit of brass chipped off. Then i tried using a small hacksaw blade to cut two groves into the brass....thinking i could use those either to get a better purchase on the brass rim to tap it around, get a slot head screw driver in there, or to collapse the brass and pull it out. Nothing worked.

I am on the mooring, so things were a bit bouncy and tools are somewhat limited.

Wondering what the best way to continue is, and what tools to bring back to the boat with me tonight or tomorrow. Am I right that the worse case scenario is to drill it out and re-tap one size larger thread? I have had a bad luck with "easy outs" so hoping not to go there.

Wht is the secret to "tapping it around"?

Does penetrating oil help?

Many thanks,
Marty

[tenders]

There's clearly some combination of rust or verdigris holding things together in there. I would first hit it with some heat and/or an acetone/ATF combo (or other penetrating elixir of your choice). I'd prefer the penetrant over the heat, as open flame makes me nervous in the engine compartment.

I don't know the specs on that hole, but I'm wondering if you could then run the drill bit specified for the tap of a hole that size to shave off some of the thickness of the brass. (Drill bits for taps often have funny-sized denominations and are specified by capital letters rather than 64ths of an inch.) Then just thread the standard tap into the hole to carve out the remaining brass. With judicious application of cutting oil and repeatedly backing out of the tap to clear the chips you should end up with a sweet, clean hole.

If you want to go a little more barbarian, this is a case where the easy-out might have a fighting chance of extracting some of that nice soft brass without breaking off in the hole. I wouldn't do that if gymnastics are necessary with this installation to get the drill next to the hole - a misalignment there will snap off the bit.

Without an oil filter, I'm not sure how concerned one would need to be about getting brass/rust shavings out of the crankcase. Anybody else have ideas on this?

[BunnyPlanet169]

Marty:

If I had one chance in life to tap that out, I'd get a LEFT HANDED 11/32 drill from McMaster Carr, and go at it very slowly with a slow speed REVERSABLE cordless drill and a shop vac. Maybe that's 4 hands at work....


11/32 or "R" drill is the tap drill for the 1/8NPT thread, and very often it will actually back the part out while drilling, and you'll be smiling at some very thin threads on the end of your slowly moving drill....

If it works, you'll only need to lightly chase the threads, again with the shop vac to clean up.

Not kidding about the left handed drill. It's worth finding one, really.

[Easy Rider]

Marty,

If lacking tools on the mooring how about trying lightly tapping a flathead screwdriver into whats left of the brass tube just enough to get a bite (kinda like a wedge) and then turning the screwdriver while at the same time putting pressure on the screwdriver toward the block to keep the bite in the brass. Be careful not to damage the threads in the block if you try this. I know it will work if the conditions are right because I've done it. I've seen this question before here so someone with more knowledge or experience is sure to chime in soon. Good luck with it.

[thatch]

Hi Marty, I realize that I am going against popular opinion here but I feel that an easy-out is the best tool for this job. I have removed several "brass into steel" nipples and have never broken an easy-out in the process. Unlike head studs or water jacket bolts, there is not really a "rust bond". Also remember that this nipple has lived it's life bathed in oil from the backside.
My favorite style of easy-out for this soft metal resembles a tapered, square cut nail with very sharp corners. When you finally succeed in removing the little bugger, it would be wise to crank the engine over several revolutions to allow the oil pump to "flush out" the debris.
Tom

[romantic comedy]

That is the oil gallery, right?

Watch the chips getting in there. Some use grease on the taps or tools to hold the chips.

[Marty Levenson]

Thanks

Very much appreciate the quick replies. Torn between drilling and tapping with current size as a chaser OR trying the easy-out. Last time I used an easy-out I ended up retrieving the pieces with a magnet.

Thinking of recreating the situation on the bench and seeing what works best before heading back to the boat. My dad used to say that recon is never time wasted.

Grease on the tools idea makes sense to me, as well as letting the engine purge some oil in case of chips after I get the thing out of there.

Thanks to all.

[Marty Levenson]

space problem

Realizing I may not be able to use my rechargeable drill in that tight spot! Can I do the easy out by hand? I would think so.

[thatch]

My procedure with an easy-out is first to gently tap it into place to start the innitial "bite". The back end is usually square so I find it easiest to use a pair of Vice-grips pliers as the handle.
Tom

[ndutton]

Realizing I may not be able to use my rechargeable drill in that tight spot! Can I do the easy out by hand? I would think so.

I prefer working easy outs by hand. Much more feel that way.

[Marty Levenson]

easy out

Looks like easy-out may be my first method. I think that I will have to take apart some significant woodwork if I need to use a drill, so make sense to avoid that.

Thanks guys.

[BunnyPlanet169]

Looking forward, if you can get a schedule 80 nipple in brass ( probably not at the local hardware store, but maybe a plumbing supply store), it has a thicker wall and you'll avoid a repeat....

[edwardc]

Looking forward, if you can get a schedule 80 nipple in brass ( probably not at the local hardware store, but maybe a plumbing supply store), it has a thicker wall and you'll avoid a repeat....

McMaster-Carr has it. An 8 inch one runs about $12.

[Marty Levenson]

coarse or fine?

If I end up drilling that out with an 11/32 drill and running a tap through (carefully!) is there a 1/8" NPT tap that is tapered....or what size do I need?

Thanks!

[BunnyPlanet169]

It's tapered pipe thread. 1/8 NPT is neither fine or coarse, it just is.

Technically, it's 27 threads per inch, but just ask for a 1/8 NPT tap....