Removing oil galley plugs, drilling and tapping Options

[930cabman]

I have looked and looked and have not found any information.

Please enlighten us with this process. I have a pile of 3/8" aluminum pipe thread plugs

TIA

[Superhawk996]

Now you did it by mentioning aluminum plugs which I’m highly in favor of but you’ll get differing opinions I’m sure. (IMG:style_emoticons/default/happy11.gif)

You’ll need other sizes besides 3/8” to do them all.

To install - heat the case - freeze the plug. Install quickly until tight. Let shrink fit take care of the rest. Don’t expect to be able to ever remove them. They will need to be drilled out.

I think I may have had some info in my case machining thread for engine GA00099. Pages 3 and 4 have info on galley plugs but obviously completion of this engine job has been delayed by life, relocation, and need to build a garage.
http://www.914world.com/bbs2/index.php?sho...38513&st=40

[Geezer914]

Are you rebuilding the engine or just replacing the plugs? If rebuilding, just remove the original plug and tap the holes. If just replacing the plugs grease the pipe tap so the shavings stick to the tap. I used short pipe plugs so they sat flush to the block. I used ARP thread sealer on the plugs.

[bkrantz]

And make sure the openings (and plugs) are CLEAN before installation and sealant application. Like surgically clean.

[930cabman]

Are you rebuilding the engine or just replacing the plugs? If rebuilding, just remove the original plug and tap the holes. If just replacing the plugs grease the pipe tap so the shavings stick to the tap. I used short pipe plugs so they sat flush to the block. I used ARP thread sealer on the plugs.

Rebuilding the engine. Are the factory plugs "easily" removeable with a slide hammer? Also, will the holes need to be opened up to a 3/8" plug drill with a flat bottom drill?

[Superhawk996]

Are you rebuilding the engine or just replacing the plugs? If rebuilding, just remove the original plug and tap the holes. If just replacing the plugs grease the pipe tap so the shavings stick to the tap. I used short pipe plugs so they sat flush to the block. I used ARP thread sealer on the plugs.

Rebuilding the engine. Are the factory plugs "easily" removeable with a slide hammer? Also, will the holes need to be opened up to a 3/8" plug drill with a flat bottom drill?

Yes - slide hammer and screw will pull old plugs

Yes - holes will need to be drilled for appropriate size plugs.

The other option I’d like to do someday is to simply machine up new plugs like OEM and shrink fit them. I honestly could have machined plugs in the same or less time than it took to prep all the holes for NPT plugs.

[MikeK]

It's been a while since I did this, but I recall one of the plugs being awfully close to an internal oil supply line. Be careful. If you mess that one up it may be time for a new case.

I had no luck with the alloy plugs, I think mine were from Skat. I ended up using brass plugs. Bear in mind that you may have to tap, fit, tap some more to get the plugs set to the depth you want. Some require a modified or bottoming tap. The aluminum fittings don't like to be used multiple times. You could fit them with steel or brass plugs, then install the alloy ones at final fit up, but I like the idea of being able to remove them without damage in the future.

[930cabman]

Are you rebuilding the engine or just replacing the plugs? If rebuilding, just remove the original plug and tap the holes. If just replacing the plugs grease the pipe tap so the shavings stick to the tap. I used short pipe plugs so they sat flush to the block. I used ARP thread sealer on the plugs.

Rebuilding the engine. Are the factory plugs "easily" removeable with a slide hammer? Also, will the holes need to be opened up to a 3/8" plug drill with a flat bottom drill?

Yes - slide hammer and screw will pull old plugs

Yes - holes will need to be drilled for appropriate size plugs.

The other option I’d like to do someday is to simply machine up new plugs like OEM and shrink fit them. I honestly could have machined plugs in the same or less time than it took to prep all the holes for NPT plugs.

Great idea, I can have my friendly machinist make them up and shrink fit them, will they need to be hollow backed or can they be solid

How does one "heat" the case, locally or in an oven to xxx degrees?

[930cabman]

Had a couple minutes and was able to pull 4 plugs with a 1/8" drill, #8 sheet metal screw and a slide hammer. A couple did not grab and will go back later with a #10 or #12 screw. Looks like a straightforward operation to clean everything and fit new machined plugs. I am not sure what sealant to use, but it will come to light

[Superhawk996]

If you do machined plugs like OEM there would be no sealant - just a shrink fit. But holes and plugs need to be smooth and round - no coarse machine tool marks.

Let me be totally transparent - I have not done machined plugs myself on a T4 engine.

When I heat the case for the aluminum NPT plugs I use an oxyacetylene torch with a rosebud head heating locally then quickly insetting the frozen NPT plug - this achieves a shrink fit as well.

[930cabman]

If you do machined plugs like OEM there would be no sealant - just a shrink fit. But holes and plugs need to be smooth and round - no coarse machine tool marks.

Let me be totally transparent - I have not done machined plugs myself on a T4 engine.

When I heat the case for the aluminum NPT plugs I use an oxyacetylene torch with a rosebud head heating locally then quickly insetting the frozen NPT plug - this achieves a shrink fit as well.

thanks for the info, I will be giving this a try on the next build, coming soon.