Pipe Plugs for Oil Galley and Extra Timing Chain Oil

B

Blown&Injected

Active Member
Joined
May 31, 2001
Hi:
I looked and looked but could not find the post about which threaded pipe plugs to use for the oil galley in the front of the block.

Went to clean the block and then went daaaaa think I ought to do this after drilling and tapping the thing:eek:

All I could find at the hardware store were set screws, not NPT pipe plugs and the NPT pipe plugs they did have had a head on them, not a allen socket.

Looks like one of the galley plugs will need to be very carefully (shallow) because of the way the oil passage meets the galley - it is close to the surface.

Any thoughts on drilling a small hole in one of the plugs to provide some oil to the timing set?

TIA
 
There's enough oil coming through the stock camshaft hole, for T/C lube (if you run a austemper roller or a stock flat tappet cam). Use 1/4 NPT tap. Tap the holes SHALLOW on the passenger side so the plug doesn't have to go so far in. Or, if you do go too far with the tap, install the plug and re-drill through the oil pressure sending unit/turbo feed hole with a long drill. You can also grind the back side of the pug off and after the lock-tite/epoxy dries you can grind the face off. You will have to drill it out at rebuild, time, but it's no big deal. I have built them out of steel (drill rod) and kept widdling on it untill it fit perfect. Then I cut a screw driver slot into the face so it could be removed after set-up, then I lock-tited it in place. Use a Propane torch to break lock-tite free. Check with your local parts store or hot-rodshop for allen plugs. I think that Duttweiler offers special plugs.
 
size

3/8 in. NPT--NPT is a tapered thread and does not need Loctite but does need teflon (liquid or ribbon tape) to lube threads so they go in fully. True that you will need allen heads and you must NOT block oil feed to drivers side. Takes some patience and grinding on both sides of plug to achieve this. Also must be flush with front of block. No need to drill lube hole in plug assuming you use slinger.
 
I got 0.57 on the on the oil galleys. It looks like a 14" NPT will work but based on this chart I found, maybe 3/8" is better for keeping the plug from going too deep.

All the local shop had were set screws. Those look right but straight threads do not match NPT threads.

NPT Size.....Tap Drill Size (in.)..(Decimal) (in.)

1/16 - 27.......... "C" ...................(0.242)
1/8 - 27 ............"Q".................. (0.332)
1/4 - 18 ............7/16................. (0.438)
3/8 - 18 ............9/16................. (0.562)
1/2 - 14 ............45/64............... (0.703)
3/4 - 14 ............29/32............... (0.906)
 
TA Performance has the right plugs for this. They even machined one of the plugs to prevent blocking the oil passage. Both plugs have allen heads in them.

Billy T.
gnxtc2@aol.com
 
Thanks - yeah I found the link (it took me to TA Performance) but was hoping to find it locally but all the stuff I have found are set screws and plugs with big heads
 
OK, definitely 3/8-18. The oil galley hole is .57" and the drill chart says .5625" for 3/8-18 NPT tap.

It seems like the way to go is to just run the tap in a bit and then test the plug
No drilling since the hole is already a tiny bit bigger than the recommended 9/16 drill

Dose this sound right?

Thanks Again.
 
Yes that sounds right. I mis spoke on the 1/4 NPT, sorry. Memory loss I guess. Cutting threads for a pipe tap can be tricky. But, if you go at it slowly, you'll be fine. Be sure to seal them with pipe sealer or alot of guys use epoxy. You'll just have to heat the plug with a propane torch to loosen the epoxy, for disassembly in the future. Most of the endurance V6 builders epoxy AND stake the plugs for safety.
 
I couldn't find the Allen plugs around here, either. I bought steel plugs with the square heads, and a pipe nipple to screw them into from Lowe's. In turn, I screwed them into the nipple 3-4 threads, and then cut off the back of the plug with a Dremel tool, extra threads and square head togehter. You will then be left with just your shallow plug screwed into the nipple. I then took the Dremel and cut a screw head slot into the plug while still in the nipple. Then, simply take a flat head screw driver and unscrew the plug from the nipple. You are done! I bought a few extra, just in case I botched one up. It took maybe 15 minutes and about 3 bucks altogether to modify the square head plugs into low profile, solid steel, screwdriver slotted head units. I wasted the first one, but the next two worked like a charm. You can even use the nipple as a thread straightener by screwing the plug into the hole and back out again. No waiting, and nice solid steel plugs in hand in a few minutes. Thanks, Counterman.
 
Found the plugs, tapped the oil galley plugs, and ground down the plugs to be flush with the front of the block.

Yes, I got some pics - may as well post them in an engine build thread, it might be helpful and I may learn some new ways to do things.
 
For future reference, McMaster-Carr sells "Flush-Mount Steel Hex-Socket Plugs" , for under $1 each. Search for part # 4534K43, for example (3/8 NPT).
 
You must log in or register to reply here.

Similar threads

we2man
Timing chain guide screw
Replies
3
Views
614
we2man
we2man
S
1987 Buick Grand National 23k miles Massachusetts
Replies
1
Views
3K
Sneaky_Pete
S
ShaunKris
Slight Knock
Replies
9
Views
4K
ShaunKris
ShaunKris
Cryptic
No Start After Timing Chain Job
2
Replies
21
Views
2K
Cryptic
Cryptic
8
Heavy white smoke on rebuilt motor upon startup
2
Replies
26
Views
2K
TexasT
TexasT
Top