Technical Which freeze plug is best?

I know that br*** ones would not rust but I seem to recall someone saying before that steel is better and I don't remember why. Also, should some form of sealer like Permatex or similar be applied? It is for my 1972 Plymouth 318 engine. Thanks for any info.
John

 

Br***

 

Br*** if you can find them,,forget the sealer. HRP

 

Some say that br*** expands at a different rate than iron so are more likely to pop out. Haven't seen it happen personally though. I always use Permatex on my freeze plugs. You can coat the inside to prevent rust, but with a properly maintained cooling system that should not be an issue.

Next topic: the difference between core plugs and freeze/expansion plugs.

 

Br*** is much better lasts forever unlike steel thats rusts away even when coated.

 

I built a couple inthe 1980's that when I put the frostplugs in I used indianhead shellac on the backs of them , no rust thru yet . and one of the motors is run with straight water . I like br*** as it forms to the hole better if its old and rusted , but had good luck with steel units too .

 

I am sorry that I can be of no ***istance to you

 

I like the cup style br*** ones with permatex #2. If the block hasnt been tanked and the holes are dirty/rusty you will need to clean them up with a small br*** wire wheel on a drill or preferably an air grinder. Core plugs and #2 wont hold in a dirty.rusty hole.

 

That's funny,and a name like freeze plug! HRP

 

Steel, and use sealer.

And the strange thing is, we both are right.

 

I've worked in the marine business for years so I always use br*** ones. Most machine shops can get them for you, maybe even NAPA and other auto parts stores too.

I also coat the mating surfaces with Permatex.

Don

 

Br*** plugs are great if you don't maintain your engine.

 

Has anyone used the new expanding rubber plugs? I used them in an old jeep where access was an issue. They also worked nicely for plugging up valve cover holes.

 

I have used expando plugs where a rotted out soft plug was in a hard to reach area and pulling tghe engine was out of the question. I would not use expando plugs in an engine that was out of the vehicle.

I like br*** but I don't think that they are any better then steel.

 

Agreed. Expando rubber plugs are just for a quick fix, not long-term. And they are certainly nothing new.

There is a technique to removing steel & br*** plugs. Cannot remember how many engines I have built where someone just punched them all the way in and installed a new one. Can you say blocked coolant p***age?

 

We always used the br*** ones on boat engines, steel on cars. NAPA or whoever carries both. I did use an expandable behind a motor mount once, too cold to lift the engine at the time, and it was in there for years.

Bob

 

i was able to find BOTH sizes that my plymouth engine calls for in br***, and on the shelf at a napa store.
the br*** is more forgiving and will work better for an engine that wasn't all cleaned up properly.

 

As Squirrel inferred, system maintenance makes either one work well and last a life time.