Oil Galley Plugs, Conventional Wisdom Options

[adolimpio]

I've read a few threads about the plugs, but there were some competing opinions, so I would like to ask for the latest thoughts.

1. What sealant should be used? One thing was clear - NO TEFLON. The most compelling suggestion was JB Weld. Is that a reasonable solution?

2. What kind of plug? Many opinions say NO to brass or aluminum because their head could be easily stripped. Steel was suggested. How about stainless? Any issue with the different expansion rates between the case and the plugs?

One thing is clear - they should be replaced. Of the 11 plugs, 2 almost fell out. They were definitely potential sources of future leaks!

Thanks for your thoughts!

[Mark Henry]

In this case it doesn't really matter which material you use, I only use steel plugs because one day I may have to take them out. Like with most engine builders it's hard to change the mindset when you have a solution that has worked for years, not to mention the couple hundred steel pipe plugs I have in stock. The dissimilar metals/leakage theory is just a no go with my thinking, metals don't expand in just one direction, they expand in all directions. If anything the pipe plug gets tighter as heat increases. I've never had a steel plug leak and I've done this mod on many of my own and customers engines. BTW the steel plug will never rust on the business side.

The pipe plugs I use have the micro-encapsulated thread sealant already on them, same as the 996 factory bolts. Took me awhile to trust this treatment, but they have never leaked. Tech tip if you get these plugs, is use a spare/bare plug to test fit the depth of the plug, then once happy install the ME plugs.

Always use a new or sharp 3/8" NPT tap, you drill to 9/16" and try to oval out the top hole, but best way is to carefully use a taper ream for proper size. I've cut the tip off of my reamer so it doesn't go in too deep. Lube the tap, there are special cutting lubes if you have them, but WD40 works good enough. Always check your test pipe plug depth as you cut with your tap. Don't worry about threads into a galley, but there's a blind plug in the front and one in the back, so don't drill in too far. The most outward hole (3-4 flywheel side) the plug must sit flush or just a hair proud or it will hit the flywheel. I leave the rest of the plugs a bit proud. There's holes with galley right behind them, the 1/2 flywheel hole (IIRC) is a hole really close to a cam galley, leave the plug almost half proud or some builders back cut the plug. Never over torque the pipe plug, but I know I put more torque on a steel plug than you ever could on an aluminum or brass plug. One thing I've never measured is the torque, the plug just stops in the taper, I give one more try and you're done.
Do install all the plugs before you start engine assembly, if there's any issue with depth you want to know before assembly.