Thread: Welsh plug maybe?

Yes, this is a Welsh plug or Core plug. They are there for two reasons, to get the casting sand out of the water jacket when the casting for the block is made, and to give the bock some chance of surviving the water jacket freezing, hence they are sometimes called frost plugs, although not usually in this country.

Lever out the remains with a suitable spike or screwdriver and clean up the seat. Measure the diameter and go to your nearest car parts supplier, should be able to get one, although there might be problems since it is certainly an imperial size - in this case try one of the Landrover parts suppliers (not a dealer). The plugs come in two types, the cup type which is a drive fit and the slightly domed type which is inserted domed side out and expands when driven in. They come in either steel or alloy, the latter is probably the best, but not much to choose. In either case the edges should be sealed with Stag or a setting gasket sealer.

You may find the job easier with the mudguard and manifolds removed, and check all the other plugs. There are three along that side and one on the back. There is also a screwed plug just next to the one you are looking at.

John