I've got the oil galley plugs out (the 2 by the oil cooler, the 2 by the flywheel on the same case half, and the one by the flywheel on the other case half). One came out real easy btw. I wonder if that one would have let go at some point.

In order to get my threaded plugs flush, I need to have the tap about 3/4 inch into the hole. Before I start drilling in that far, does this sound right? The flywheel galleys look like I could go in that far but the two by the oil cooler don't.

Here is the tap I'm using.

Click to view attachment

Based on what I could find on the internet, the basic size of the pipe tap occurs about 12 threads from the front of the tap, which by my calculation is 12/18th of an inch. I confirmed this with a caliper.

Based on the drill bit having a point, I would need to drill into the case 12/18th of an inch plus the length of the tip, which is probably over 3/4" in total. Is this too far to drill? If so, I'm thinking I could drill in 1/2" and run the tap in 1/2", then grind some off the front of the tap so that I can get to that 12th thread.

Am I over thinking this? I just don't want to ruin the case.

Flywheel side #1 you will tap a bit into/past the one cam feed galley, so you have to be sure the plug won't go in so deep as to block the passage. #1 has to be in flush to clear the flywheel.

Fan side (and the other plugs) it's OK to leave the plugs a bit proud.

Which one is the #1 plug on the flywheel side?

I still don't know far can I drill into the case or whether I need to grind down the tap.

You might want to consult with the fellow at the machine shop. I don't know how easy it would be to grind down a tap.

Jake Raby may have the best answer to your question.

37/64" drill bit will make tapping easier.

I used TWO taps. One was cut in half to keep from going too deep and the other was used to start the threading with. Use lots of cutting oil.

I documented my galley plug install pretty well, see the last set of pics towards page two, sorry i did not count the threads, but see my pics and it can give you and idea. I used Raby's kit.
http://www.914club.com/bbs2/index.php?show...20out&st=20