235 6 expansion plugs

Just wanted to get a little advice on the expansion plug on the front of the 1954 235 6cyl., started mine after the rebuild and found that the front expansion plug (the one just behind the water pump) was leaking (now it has a hole in it). My question is why is this a different type of plug than the ones in the side of the block (it appears to be put in cup side first, I know that is how it is supposed to be, just wondering why), and is there any specific installation tips/tricks that I need to be aware of, or do i just get a BFH and whack away at it till its in? The part store guys around here are not much help so I just wanted to get some opinions before I do something stupid.

 

Clean the rust and crap out of the hole and then put in a new one with the convex side facing you. Tap the convex bulge down gently until it is flat. That explains why it stays in. The plug size expands as you tap it flat. I can't explain why it is a different design than the ones on the side.

 

put sealer on it too, something like Permatex Aviation Gasket Sealer

 

I always wanted to know why as well. If it contiues to leak put gasket sealer on it. I had to change my thermostate and asked my self the same question 4 years ago.

 

I always thought it was that way for water flow - But I think I have put one in like all the others - There again I Think I Have!

 

If one has a rust hole in it you can bet the others are not far off. I replaced a rusted out one one my 216 and in 2 weeks the one on the front side started peeing a stream so I switched them all.

 

Thanks for the info! The machine shop that boiled the block replaced all the other ones but that one...I don't know why they left that one in. When I pulled it out there was a big glob of rust/scale/crap that came out with it and it gives a really good view of the water jackets pretty far back so it would have been a good one to remove for cleaning. I used to use (a very long time ago...in the 80's...man I'm getting old), the brown Permatex goop that never hardens up to put in freeze plugs and to seal up the water pump, I seem to remember it worked pretty good, is that the stuff you guys are talking about? Or would it be better to use a silicone sealer?

 

Yeah, the brown goopy stuff. It's traditional, too.

 

Awesome! I like that stuff, though it gets all over the place (fingers, hands, hair, nose, zippers, etc.).

 

New plug is in, and a new waterpump, no leaks as of yet.