hiya boys, I was hoping some one could clear this up for me.

 

I had my 4a block acid dipped and bored ready for it's rebuild and was told by my father in law that, if i have a engine block acid dipped that i have to replace all the core plugs and any non ferrous metals parts that might be on it. (he is a yardy and has given me heaps of bum steers)

 

I was thinking about replacing them any way, but I wanted to know is:

 

Does the core plug "NEED" to be replaced, is it "just in case" or while it's out do every thing you can.

 

 

Thanks

 

 

 

Chris

Just FYI, engines aren't actually put in an acid solution, its a strong alkali so base your decisions on that. Any metal thats going to degrade in an alkali will need to be replaced. Probably the main metal to look for that will be adversely affected is aluminium.

hiya boys, I was hoping some one could clear this up for me.

 

I had my 4a block acid dipped and bored ready for it's rebuild and was told by my father in law that, if i have a engine block acid dipped that i have to replace all the core plugs and any non ferrous metals parts that might be on it. (he is a yardy and has given me heaps of bum steers)

 

I was thinking about replacing them any way, but I wanted to know is:

 

Does the core plug "NEED" to be replaced, is it "just in case" or while it's out do every thing you can.

 

 

Thanks

 

 

 

Chris

 

 

G`day mate, I haven`t actually worked on a 4A motor, so I am assuming that the plugs in question will be similar to the 4K variety. They have some alloy plugs and some steel plugs. Because the acid dipping process uses a hot caustic solution, it is not impossible that the alloy ones will be effected. Maybe not on the outside, but where there has been scale buildup/corrosion on the inside.

What I personally would do,considering the minor extra cost, is replace them all just for peace of mind. You have obviously done the right thing by your engine having it bored, new pistons etc so it would be a tragedy to have a "new" motor fail because of a set of welsh plugs that cost very little and are a simple job to fit.

Good luck with the build.

Steel ones wont dissolve, Brass ones may also be fine BUT - for arguments sake, we are talking about 2 dollar parts; theres about 7 of them in a K series block, of varying sizes, by my conservative overestimate, it will cost you 15 dollars to do them.

 

And to be honest, you would be CRAZY to rebuild a whole engine from scratch and not replace the welsh plugs.

 

Not really a problem for you as it's an OHC motor, but K engines and other pushrod motors need to have the camshaft bearings replaced as the hot dipping eats that out.