Freeze Plugs

[Straightliner59]

I thought this might be an interesting detail to add to the engine for my supermodified racer. It's the kind of detail that will probably never be noticed. It's also the kind of tiny detail that might put a model over the top, in a closely-contested...uhh...contest. I just wanted to see if I could do it, what it would look like. That's why I do most of this silly stuff. It's what I enjoy!

Pictured here are the tools  and materials used to make and install the freeze plugs in the Small Block Chevy from Monogram's Don Edmunds Supermodified kit. Unfortunately, I forgot to include the plastic rod and drill in the photo. I used a Micro Mark punch and die set, but, any punch will work, so long as you can retain the discs. Select a punch to create a disc slightly larger (say .040") in diameter than the holes you drilled. The pin punch should be about .020" smaller than the discs you make. A small hammer will suffice, here--we aren't looking to kill anything! The material I used to create the freeze plugs is Maid-O-Metal 36 ga. tooling aluminum. This material is nicely malleable, and is slightly softer than the aluminum from disposable baking sheets, although, those would work just fine, in this application.

Begin by drilling out the molded-in plugs. Select some plastic rod that fits snugly into the holes you just drilled, and cut four pieces (in my case--circumstances may vary) approximately 3/16" long. Insert them, one at a time, into their respective holes. Here, I used my thumbnail as a simple depth gauge to push them about .030" deep, into the holes and cement them into place. Set it aside to dry.

Now, punch some aluminum discs. It's always a good idea to make extras, while you have the tools out.

Now, center the pin punch (brass or steel rod will also work) on a disc, on a cutting mat, and tap it firmly with the hammer.

You should end up with something like this:

All that's left to do is to insert them into the holes you drilled earlier. The lengths of rod inserted earlier provide a solid backstop for the newly-formed freeze plugs, making installation a breeze!

Before I paint the block, I will dab tiny bits of petroleum jelly (how's that, for old-school masking agent?!) on the plugs. Once the paint is dry, a quick swirl of a cotton swab will expose the metal beneath, creating  realistic-looking freeze plugs for your next project.

 

[4mula1fan]

Very creative! I'll have to try this on some big scale projects. 

Edited October 2, 2021 by 4mula1fan

[Straightliner59]

1 hour ago, 4mula1fan said:

Very creative! I'll have to try this on some big scale projects. 

It should work just fine, in any scale. Have fun!

[deuces wild]

It might also work with soft brass sheet if that stuff is available....🤔

[Straightliner59]

40 minutes ago, deuces wild said:

It might also work with soft brass sheet if that stuff is available....🤔

K&S makes stuff called "shim brass" that would work, beautifully, once annealed!

[deuces wild]

Cool, thanks!...👍

[iBorg]

Once again Dan you throw out something that is a great detail I'd never had thought of.

[Modelbuilder Mark]

Nice touch

 

[Straightliner59]

7 hours ago, iBorg said:

Once again Dan you throw out something that is a great detail I'd never had thought of.

Thank you, Mike. I appreciate that!

[Straightliner59]

3 hours ago, Modelbuilder Mark said:

Nice touch

 

A nice, simple detail can add so much to a model! Thanks, Mark.

[bobthehobbyguy]

Thanks for a cool detailing tip. 

[Straightliner59]

On 10/3/2021 at 10:55 AM, bobthehobbyguy said:

Thanks for a cool detailing tip. 

Always happy when I can help!

[peteski]

Interesting detail, but aren't those already molded on the engine blocks?

[Straightliner59]

1 hour ago, peteski said:

Interesting detail, but aren't those already molded on the engine blocks?

Sure, but molded-on is not always better! Besides ,  what's the fun, in that?! I😀

Edited October 5, 2021 by Straightliner59

[R. Thorne]

Outstanding job.  Thank you.

[HJK]

Hi Daniel, Thanks for this detailing hint. I've never heard the expression 'freeze plugs'. Can you please tell me what they are for and why are called like that? Thanks, Juergen.

[NOBLNG]

If you do not have a strong enough anti-freeze mixture in your coolant system, or just use water, it can freeze in cold weather. The inadequate coolant would expand and could crack your engine block casting. The freeze plugs are a press fit and are designed to be forced out by the expanding coolant in order to protect the block.

Edited October 8, 2021 by NOBLNG

[NOBLNG]

4 hours ago, HJK said:

Hi Daniel, Thanks for this detailing hint. I've never heard the expression 'freeze plugs'. Can you please tell me what they are for and why are called like that? Thanks, Juergen.

See above post. Also, the block heater is usually installed in place of one of the freeze plugs.

Edited October 8, 2021 by NOBLNG

[peteski]

There even is a Wikipedia article on them: https://en.wikipedia.org/wiki/Core_plug

[Classicgas]

Interesting detail, but factory stock plugs would have been painted engine color, so the molded in ones would be fine. Unless for some reason the kit engine has none. Very cool.

[Foghorn Leghorn]

20 hours ago, NOBLNG said:

The freeze plugs are a press fit and are designed to be forced out by the expanding coolant in order to protect the block.

That's an Old Wives Tale. The holes and plugs are there so the core sand can be shaken out after the casting process.

Here's one i done. I painted over everything later. But  stopped in midstream to make proof that i used brass plugs because mild steel plugs can rust thru from the outside-in.

I did put in the cam bearings right after this. The plug driver is handmade. It's crowned to mimic the curvature of the plug center.

 

Edited October 9, 2021 by Foghorn Leghorn

[Straightliner59]

4 hours ago, Classicgas said:

Interesting detail, but factory stock plugs would have been painted engine color, so the molded in ones would be fine. Unless for some reason the kit engine has none. Very cool.

My thought is to use tiny dabs of petroleum jelly as masking agent on the freeze plugs, before paint, then swabs it off with a Q-Tip, once the engine is painted. That should expose bits of metal, beneath. It should look pretty convincing. I hope!

[peteski]

3 hours ago, Foghorn Leghorn said:

That's an Old Wives Tale. The holes and plugs are there so the core sand can be shaken out after the casting process.

Can't they serve dual purpose?  Allow to drain the sand from the casting, and when plugged up, serve as freeze plugs?

1 hour ago, Straightliner59 said:

My thought is to use tiny dabs of petroleum jelly as masking agent on the freeze plugs, before paint, then swabs it off with a Q-Tip, once the engine is painted. That should expose bits of metal, beneath. It should look pretty convincing. I hope!

If you want to show them in natural-metal finish, why not install them after the block is painted?  Also, in factory stock engines they would be painted the same color as the block anyway.

[Straightliner59]

Just now, peteski said:

Can't they serve dual purpose?  Allow to drain the sand from the casting, and when plugged up, serve as freeze plugs?

If you want to show them in natural-metal finish, why not install them after the block is painted?  Also, in factory stock engines they would be painted the same color as the block anyway.

It's a racing engine. It's just something that I think will be an interesting touch, with little chips out of the paint, because it didn't adhere as well to the slicker surface.

[Foghorn Leghorn]

22 hours ago, peteski said:

Can't they serve dual purpose?  Allow to drain the sand from the casting, and when plugged up, serve as freeze plugs?

On this side of the pond, water turns to ice in half the country every winter. Come over here and tour a few scrapyards. Iron cylinder cases split open from when ice expands. Oh sure, sometimes the 'freeze plugs' are partly pushed out but there are never enough plugs to save the engine case. When the ice runs out of room to grow, it pushes its way out any way it can.

I remember one winter a kid that i knew had a 1969 Chevy Nova with a hot rebuilt engine. It got really cold one night and all he had was straight water in the engine. For some long-forgotten reason it couldn't run. He needed a heated garage but had no garage at all. So he put it on jackstands and built a charcoal fire on the ground under the engine. Desperate times require desperate actions. I never heard how it came out but he was in a panic that night due to his own poor planning.