Reusing Welsh Plugs

[losh1971]

Would repco have the genuine ones in stock, or do they usually have to order specific stuff like that in?

Stock varies from store to store, you would need to call them.

 

[losh1971]

These will probably be the closest ones to Yass.

 

[EYY]

You'll probably find that they were stainless units originally fitted and those are damm expensive. just the one in the rear of the head is around $12.00 each in stainless.

Wouldn't touch steel ones in a fit, but the cheaper alternative to stainless is Brass.

Nah they’re just mild steel - that’s why they rust out. Done on purpose from the factory as the plugs are more willing to corrode than the cast iron. In other words they’re a scraficial anode.

You lose this when you go to a brass Welch plug but if the correct coolants are used and the block is adequately earthed there shouldn’t be any issue with regards to corrosion.

I usually pay $35-50 for a full engine set depending on what it’s for.

 

[Tristan Cupit]

View attachment 202987

These will probably be the closest ones to Yass.

Thanks for that. All of this has been much appreciated.

 

[Tristan Cupit]

Nah they’re just mild steel - that’s why they rust out. Done on purpose from the factory as the plugs are more willing to corrode than the cast iron. In other words they’re a scraficial anode.

You lose this when you go to a brass Welch plug but if the correct coolants are used and the block is adequately earthed there shouldn’t be any issue with regards to corrosion.

I usually pay $35-50 for a full engine set depending on what it’s for.

I know it's a kind of dumb question and not quite relevant to the rest of this thread, but how can you reasonably prevent the block from rusting to all buggery if I put brass plugs in? Water is the coolant stuff and "water" isn't it? Wouldn't that rust?

 

[lmoengnr]

I know it's a kind of dumb question and not quite relevant to the rest of this thread, but how can you reasonably prevent the block from rusting to all buggery if I put brass plugs in? Water is the coolant stuff and "water" isn't it? Wouldn't that rust?

That's why you use the correct coolant! They have rust inhibitors...

 

[vs-lover]

Nah they’re just mild steel - that’s why they rust out.

Well that's strange as the one owner 45,000km damaged (crashed) VS Series I that I purchased as an engine donor for my wagon had stainless plugs in both the block and heads and this vehicle was genuine out of the factory and not messed around with, also after I knocked out a plug from the block and both of the rear head units I found them to be bright shiny steel and as such I didn't proceed to knock the other out.

I proceeded to go to Motor Traders in Adelaide (Coventrys in Perth) who were GM parts distributors and they told me that they haven't sold any of those in years as they are stainless. They actually had to order me one of the rear head plugs from HSPO in Melbourne as they only had a single in stock. Believe me Traders stock levels were always high due to their massive sales to the trade (in both panel and mechanical) and to only hold one was proof that they sold none, and why would that be ?

Sorry but I don't quite buy the sacrifical anode story as these are just used to seal off the casting pouring inlets and are the provision for the casting sand to come out of the internals of a block. Mild steel is purely used due to cost cutting and thus why Brass and stainless units are available but at a higher costing.

As far as making sure you are buying genuine brass, I'd take a small magnet with me and give them the quick once over when they are handed to you to ensure you're buying brass and not brass plated mild steel as a con.

 

[losh1971]

Only ever had one welsh plug leak in 31 years of car ownership and that was on an old 67 Morris Mini that only ever run straight water. Not saying don't replace them if you have the engine out but the need for brass or stainless, I'm not convinced they are needed if the correct additives are used.

 

[vs-lover]

Losh you are absolutely correct, if you used the correct coolants etc. you'd never have an issue, but there are so many folks out there that couldn't give a rats and just use water as it's cheaper. This shows up especially in South Australia as we have the hardest water in the country and it doesn't take long to chew out anything using straight water.

As you suggest in a roundabout way that if you have an engine out and intend on the car being a keeper, putting new welch plugs in is a given as try replacing one while the engine is installed, especially the rear ones.

 

[EYY]

Well that's strange as the one owner 45,000km VS Series I that I purchased as an engine donor for my wagon had stainless plugs in both the block and heads and this vehicle was genuine out of the factory and messed around with, also after I knocked out a plug from the block and both of the rear head units I found them to be bright shiny steel and as such I didn't proceed to knock the other out.

I proceeded to go to Motor Traders in Adelaide (Coventrys in Perth) who were GM parts distributors and they told me that they haven't sold any of those in years as they are stainless. The actually had to order me one of the rear head units from HSPO in Melbourne as they only had a single in stock. Believe me Traders stock levels were always high due to their massive sales to the trade (panel and mechanical) and to only hold one was proof that they sold none, and why would that be ?

Sorry but I don't quite buy the sacrifical anode story as these are just used to seal off the casting pouring inlets and are the provision for the casting sand to come out of the internals of a block. Mild steel is purely used due to cost cutting and thus why Brass and stainless units are available but at a higher costing.

As far as making sure you are buying genuine brass, I'd take a small magnet with me and give them the quick once over when they are handed to you to ensure you're buying brass and not brass plated mild steel as a con.

My mistake - they did use stainless on the 6’s from vr-vy. Definitely not on the 304’s though which is what I spend most of my time with.

I understand how the casting process works very well. And also galvanic protection. It’s a two birds, one stone sorta deal. Well, really, 3 birds when you consider them ‘freeze plugs’.