Thread: Core / Welch Plugs

Originally Posted by Lotz-A-Landies

Except those three items (cups) are core plugs and not Welch Plugs!

Welch plugs require a shoulder inside the core hole, these shoulders are not present in Land Rover blocks.

my engine has both domed welch plugs and cupped welch plugs

which is how they have always been referenced in the trade in australia since before my entrance in 1971 till now in my experience

you get get a pretty comprehensive list of those available here

The thread system used in the screwed ones is British Standard Conduit (BSCon) which is thoroughly obsolete and no longer used except by restorers or sparkies attempting to match up to very old work. Taps and dies are almost unavailable and very difficult to source. Demand is so small that I haven't bothered stocking any for probably ten years. Damien White, 07 3807 0798 did have some as did Bruce Gardner at BSF Bolts, 0408 056 255.

BSCon is a 55 degree Whitworth thread form. Not to be confused with BSC which is British Standard Cycle, a 60 degree thread form.

Originally Posted by Lotz-A-Landies

Except those three items (cups) are core plugs and not Welch Plugs!

Welch plugs require a shoulder inside the core hole, these shoulders are not present in Land Rover blocks.

They are all strictly speaking 'core plugs' ie. plugs that seal holes that were used to support the core for the water passageways during the casting process.
Welch plug refers to the domed type that expand when hit in the centre.

A lot of things change name and a general name is adopted over the years. I think most people know what is meant by a Welch plug and/or a core plug.

At least they're not being referred to as 'freeze plugs'.

Some interesting notes from the original manufacturer of the Welch Brothers 'Welch' plug.
http://hubbardspring.com/subcategory...ansion%20Plugs



Colin

Originally Posted by Brian Hjelm

The thread system used in the screwed ones is British Standard Conduit (BSCon) which is thoroughly obsolete and no longer used except by restorers or sparkies attempting to match up to very old work. Taps and dies are almost unavailable and very difficult to source. Demand is so small that I haven't bothered stocking any for probably ten years. Damien White, 07 3807 0798 did have some as did Bruce Gardner at BSF Bolts, 0408 056 255.

BSCon is a 55 degree Whitworth thread form. Not to be confused with BSC which is British Standard Cycle, a 60 degree thread form.

and i lend mine out with a security deposit that they get back when i get my tap back in good nick.

Originally Posted by gromit

They are all strictly speaking 'core plugs' ie. plugs that seal holes that were used to support the core for the water passageways during the casting process.
Welch plug refers to the domed type that expand when hit in the centre.

<snip>

Colin

Absolutely agree that they are both types of core plugs, however as a teenager with my first 80" and a core plug leak I went to the auto parts store (they knew what they were talking about then) and asked for the correct size welch plug. Then spent the rest of the day trying to work out how the hold the plug so it didn't push through.

In the dim memory of my current dotage, I even seem to remember losing the disk into the block.

The problem was solved with a correct cup shaped core plug.

Interestingly, last year other AAVA members were attempting to fit a cup type into a WWII International Harvester half track and it kept falling out. When I was eventually allowed to have a look by the greater minds present, the hole was designed for a welch plug. When the correct item was acquired the plug went in without problem. I think the minds learned something new that day!

Originally Posted by incisor

my engine has both domed welch plugs and cupped welch plugs

which is how they have always been referenced in the trade in australia since before my entrance in 1971 till now in my experience

you get get a pretty comprehensive list of those available here

It's pretty sad when the suppliers get it wrong.

where ever it leads....

I guess I'm being rather pedantic.

Is this the place where I can talk about my Discovery 4 Jeep?