3 replies to this topic

[Redbaron6969uk]

Could anyone advise the best sealant to use when replacing my new core plugs and oil gallery plugs please?

Cheers

[Guess-Works.com]

Oil gallery plug use nothing, core plugs I use a very thin smear of hylomar blue, then wipe the excess off.

Obviously make sure the holes which the plugs go in are clean and free of any rust or previously used material before putting new plugs in.

[tiger99]

Green Hermetite used to be recommended for core plugs, but any hard-setting gasket compound should be ok. In one emergency situation I used Araldite Rapid, as it was all that I had, and it was ok for many years.

If the oil gallery plugs are tapered brass, they are just hammered in with a flat-nosed drift or punch, and make a perfect seal without any sealant, as the softer brass deforms to fit the hole exactly, while remaining very tight. Personally, I prefer to put them in dry, as stray sealant will only migrate to where you really do not want it to go.

[dklawson]

Over the years I have used epoxy and RTV silicone rubber on core plugs. Both work, however, if you use RTV, wipe the excess off completely (gasoline on a paper towel or two) so that when you paint the block the paint will adhere properly.

If your block has threaded galley plugs (once a common change during rebuilds) then a bit of non-hardening gasket sealant on the threads will seal them well enough. If they are the stock tapered plugs then no sealant should be required.