Frost plugs

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erafuse

erafuse

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Have a 1973 Dart Swinger 318. One of the frost plugs started leaking (easiest to replace front head drivers side) I replaced it. To replace the rest of them does the motor have to come out or can you do it by taking the transmission out. 66,000 miles on the car since one started leaking I am assuming it’s better to replace them all.

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Royal pain in the *** to do this with the engine in the car. Get a kit that uses marine grade brass plugs and you will never do them again.

BTW those are called "core plugs" not frost plugs or freeze plugs. They have nothing to do with an engine block freezing and then popping out to save it. Oh they will pop out when water left in the block freezes, and the block will still be cracked.

They are called core plugs because these holes are where the casting sand was held in place for the water jackets when the engine block was cast. The rough sand cast openings are then machined for a finish plug for the water jacket.
 
Pull the engine so you can pop them all out, and then pressure wash all the nasty crap out while you’re at it. There are 2 in the back of the block, and then the 2 in the back of the heads that will all be much easier out on an engine stand. I had to do the same thing with a 71 Challenger once, and it snowballed into TTI headers, a 727 transmission, 7 1/4 to 8 3/4 swap, a new cam and a D4B intake I had laying around.....lol.
 
JDMopar said:
Pull the engine so you can pop them all out, and then pressure wash all the nasty crap out while you’re at it. There are 2 in the back of the block, and then the 2 in the back of the heads that will all be much easier out on an engine stand. I had to do the same thing with a 71 Challenger once, and it snowballed into TTI headers, a 727 transmission, 7 1/4 to 8 3/4 swap, a new cam and a D4B intake I had laying around.....lol.
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This?

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Make sure you use the correct plug installation tool to push them in. Using a socket in the dish of the plug will collapse the outer rim and coolant pressure with motor running will push them back out. 2 are behind the flywheel and you will be cussing when you have to yank the motor back out after doing so to replace them again. Ask me how I know.
 
On the Cosworth racing engines that my brother builds, during the block prep one of the steps is to drill 8/32 holes, tap and face the hole for a small washer that has a bit of the lip over the edge of the core plug to hold them in, one on each side of the plug..
 
ch1ll said:
Make sure you use the correct plug installation tool to push them in. Using a socket in the dish of the plug will collapse the outer rim and coolant pressure with motor running will push them back out. 2 are behind the flywheel and you will be cussing when you have to yank the motor back out after doing so to replace them again. Ask me how I know.
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Man and to think I have been doing it wrong for 50 years! Guess I’ve been lucky?
 
I always just took an oversize socket that when turned upside down would bridge the outer rim, stick an extension in the "nut" end and drive the thing in. Put some sealer on, of some sort.
 
ch1ll said:
Make sure you use the correct plug installation tool to push them in. Using a socket in the dish of the plug will collapse the outer rim and coolant pressure with motor running will push them back out. 2 are behind the flywheel and you will be cussing when you have to yank the motor back out after doing so to replace them again. Ask me how I know.
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OK. How do you know?
Just kidding. I have a dozen of those, "Ask me how I know" stories.
 
SGBARRACUDA said:
Man and to think I have been doing it wrong for 50 years! Guess I’ve been lucky?
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harrisonm said:
OK. How do you know?
Just kidding. I have a dozen of those, "Ask me how I know" stories.
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blew the same one out behind the flywheel twice on my first engine build. had to pull the motor twice. and they do make a tool for installation, drives on the lip and has a shoulder the inner diameter of the plug so it drives in straight and you don't hit your block.

just like the grease cup for your front spindles, they make a tool to drive those on too. every time I see someone drive one on with a hammer or channel locks or what ever is handy I think the hammer mechanic I used to be.
 
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