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Just got my 327 back from the machine shop after a full rebuild. I was priming the engine for installation and noticed a leak from the galley plug directly above the oil filter. It is a 3/8 press in plug. Should it be? I figured this would be a threaded plug. Pic of plug
If removed by the Rebuilder.......Have him pull, clean and replace.....While the block is accessible.......If that is not the case, IMO......I would remove, clean the galley, mud up the replacement plug with a high heat gasket maker and press in.......Remember....That is what I would do!!!!! I haven't removed and replaced a "Freeze Plug" for 50 years....(912 Porsche Engine rebuild).....LOL!
HELL, after looking at the picture.....It could be that the plug was put in backwards????
Others, Please chime in.............
Pic from when the engine came out. Looks to be a screw in plug. Hard to tell. Maybe I should just pull the galley plug out and see if it is threaded behind it
Originally Posted by dcamick
If removed by the Rebuilder.......Have him pull, clean and replace.....While the block is accessible.......If that is not the case, IMO......I would remove, clean the galley, mud up the replacement plug with a high heat gasket maker and press in.......Remember....That is what I would do!!!!! I haven't removed and replaced a "Freeze Plug" for 50 years....(912 Porsche Engine rebuild).....LOL!
Others, Please chime in.............
Pic from when the engine came out. Looks to be a screw in plug. Hard to tell. Maybe I should just pull the galley plug out and see if it is threaded behind it
Partsguy1965,
Look at my edited statement......I believe the concave side of the plug should be facing out prior to being punched into the galley...I can't tell if that is the case from the picture......You would need to pull to see if it is threaded. If it is....then check to see if you can start a tap to check for thread damage.........
As I mentioned before, this is not a thread in OR standard size soft plug. Don't want to rain on your parade, but your in for a bit of a fight. Same as the one on the top under the driver side head in the rear. I would not tap them as you will probably never find the right size threaded plug.
You could drill larger and tap to correct size but drill and tap shavings into the engine is a potential problem, if doing so should be done before block cleaning. The OEM plug is not your normal type oil galley plug. It is a solid 1/2" plug about 1/4" thick. This change to threaded was around 1968 from the Tonawanda plant as I recall
That hole size, as I recall, measures .560" (nominal) from G.M. when pressed in. This would require a .562"+ (nominal) plug to fit correctly. Can be fixed by machining a solid type plug to the correct size (.563"), and loctite it, and pressed it in place. When I had my block bored the machine shop told me they never take these out on the older blocks because you can never get them to seal properly and they always leak. (old shop that has been building racing engine for 40 years)Check all your numbers but this is correct as I recall, as they say, "been there done that" Good Luck
Thank you for the reply. I pulled the old plug out and bought a plug. I coated to with sealant and pressed it in to the step in the back of the hole. The one that was there was only pressed flush with the bore, so I am hoping the sealant and the fact it is pressed all the way to the step works. I am letting the sealant dry overnight to be sure.
I always remove every oil gallery plug so they can be cleaned properly. A lot of the early blocks had the thin drive in plugs but the solid is much better. I'm helping a guy with a 64 327 now and I drilled all of the plugs out. I will tap them for pipe th evaded plugs before we finish but that is before final cleaning.
Check your PMs.
Last edited by Robert61; Mar 24, 2019 at 05:07 PM.
You might want to put some JB weld on the outer side also as this is a high pressure port and you don't want it to blow out and lose oil pressure to the mains.
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