The Stovebolt Site Forums The Shop Area Engine Shop Brass or Steel Expansion Plugs?

NAPA sells both the original steel style and the newer brass style for L216. Any opinions on or preferences for. I'm thinking steel like original for the block end plugs and brass for the block side and main oil supply galley plugs.

I would go with the original steel simply because its not as soft as brass.

i would use brass

well, i've seen steel ones rust thru- brass won't. oviously if you take care of the cooling system it prob won't that soon. i like the way brass ones drive in and i feel they are the best choice and what i have used. however i am no pro. i wouldn't worry about it being softer.

Okay,that's helpful. Brass it is. Should I use sealant?

Hy guys, I'm just going to put this out there for you to consider, I prefer to use steel. The brass ones work just fine, but disimilar metals can cause electolisis, and frost plugs are a lot of metal.

i think most machine shops install them dry. i use a tad of rtv, haven't had a leak in mine. good point 3B, but there are several brass parts making conections like fittings and temp units. who knows if it's that big a problem.

Everything is relative when dealing with galvanic corrosion of metal (which, technically, is not electrolysis, which is the breakdown of the fluid conductor).

The less "noble" the metal the more reactive it is (resulting in greater galvanic corrosion of that metal).

Less Noble to More Noble order:

Less Nobel (more reactive)
Mild Steel
Cast Iron
Brass
Stainless Steel (certain types in certin electrolytes)
More Nobel (less reactive(

So, it looks like cast iron would corrode more relative to brass; however, steel would corrode more rapidly relative to cast iron).

http://www.answers.com/topic/galvanic-corrosion-1

No matter what you use, no more time that it takes to use some sealer is time and money well spent. Try and get by without using it just once, and see how much grief you'll put on your own head when you have to pull it all back out and do it over. Just my .02 and the voice of experience talking.

Thanks for the informative responses. One article I recently read suggested using Red or Green Loctite.

Brass is generally used in marine applications. Electrolysis is not a problem unless you are using a conductive fluid like salt water. With distilled water and ethylene glycol, there is no electrolysis. Plus, anything aluminum would disappear before iron or brass.

"Electrolysis is not a problem unless you are using a conductive fluid like salt water. With distilled water and ethylene glycol, there is no electrolysis."

If electrolysis (galvanic corrosion") is not problem when you use anti-freeze, why is this topic being discussed?

"Plus, anything aluminum would disappear before iron or brass."
Why would aluminum disappear if there is no electrolysis (galvanic corrosion)?

There is no question that aluminum would corrode faster than iron and that iron would corrode faster than brass (as long as they are all inter-connected to each other and in the presence of an electrolyte).

The link above shows:

Less Nobel (more reactive in the presence of an electrolyte)
magnesium,
zinc,
aluminum,
mild steel,
cast iron,
stainless steel (type 410, active),
lead,
Monel,
Muntzmetal,
manganese bronze,
naval brass,
yellow brass,
aluminum bronze,
copper,
silicon bronze,
nickel, and
stainless steel (types 304, 316, and 410, passive)
More Nobel (less reactive in the presence of an electrolyte)

The 1954 235 engine that I am now working on has copper/brass block-casting plugs (they actually are not freeze plugs or expansion plugs) and they look OK. After looking up a little information related to this topic, I now feel more comfortable leaving these plugs in place.

Why dont aluminum radiators fail quickly? (or do they?)

well i don't know about the rest of you guys but i always use a bimetallic union when i install my freeze plugs. a alum rad doesn't touch the engine it's seperated by the rubber hoses. i think if you keep the cooling system in proper shape and change your antifreeze and only use distilled or di water you won't have that much a problem. no ions to conduct current, i guess. i have heard of this ruining parts even on newer vehicles if they cooling fluid was let go to pot.

My machinist used brass on my 1954 261 block.