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Discussion Starter · #1 ·
I believe they are called soft plugs ,, I have a good 304 for my 74 CJ-5 & before I install it Im replacing a few things That are easy to get to ,, Water pump. New timing gears & chain & a new clutch assy,, & I noticed the soft plugs were rusted up pretty good & one had a small hole in it ,, ($.50 sized plugs on the heads & the block) What I need to know is do you put a sealer on the new ones as your reinstalling them ?? I looked on The search thingey but turned up nothin. This motor has 20 K on it but it was in a Cj that was rotting away for a couple years,,, Its been under a tarp since i had it ,,
 

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freeze plugs?
 

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Discussion Starter · #3 ·
Yeah thats what there called ,,, I had a brain fart & couldnt remimber...
 

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you do need sealant, but i dont know what kind...chiltons wont tell me /ubbthreads/images/graemlins/frown.gif

somewhere along the way i read that brass freeze plugs are better than steel since they wont rust on you
 

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Per the '78 FSM:

1 Remove core plugs with hammer, chisel and prying tool.

2 Apply sealer to edges of replacement plug and position plug with lip to outside of block.

3 Install with hammer and suitable tool.
 

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They are actually called 'Core Plugs' but common usage calls them 'Freeze Plugs' even though they have nothing to do with 'Freezing'...

If the engine's coolant freezes enough to pop one of the core plugs, the block is already shot anyway...

Core holes are there to clean the sand (or what ever casting material) from the manufacture mold out of the block.
This is also where the molds were held in place during the casting process.

Remember, any empty pockets in the block now, had something in them when the block was cast, and every place there is iron was a void during casting...

Those holes were actually where the mould pieces were held in place.
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You can use expandables, but a lot of people don't have good luck with expandables.
Some people don't have very good luck with drive in plugs either.

I prefer brass when I'm using drive in plugs.
A little harder to find, but worth the hunt!
They Seal better and for a longer period of time.
 

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pretty much any good sealant will work, we use rectorseal #5(pipe dope)on the ones on our equipment here at work, i believe permatex and the like would be good as well.

if memory serves (suspect, 'specially after all the abuse/ubbthreads/images/graemlins/grin.gif) the new ones will be slightly concave, seal it, gently tap into place, and give the center(point of the "concaveness") a good rap (hammer to brass drift pin) and it expands the plug slightly, completing the seal....

make sure you wait till whatever sealer you used has had enough time to cure before filling...
 

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[ QUOTE ]
They are actually called 'Core Plugs' but common usage calls them 'Freeze Plugs' even though they have nothing to do with 'Freezing'...

If the engine's coolant freezes enough to pop one of the core plugs, the block is already shot anyway...

Core holes are there to clean the sand (or what ever casting material) from the manufacture mold out of the block.
This is also where the molds were held in place during the casting process.

Remember, any empty pockets in the block now, had something in them when the block was cast, and every place there is iron was a void during casting...

Those holes were actually where the mould pieces were held in place.

[/ QUOTE ]

hhhmmm, thanks Aaron, didn't realize all that. I do understand the molding proccess fom making some Bronze scupltures before, but never really thought about it on an block.

7am, and I can check off "Learn something new today" from my list.
 

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Dang, Brent, that wasn't my goal!
I just wanted to waste some time and that was the only thing I could come up with.../ubbthreads/images/graemlins/grin.gif

I watched them cast heads one time. Very interesting...
(I almost said 'Very Cool!' but it was very hot/ubbthreads/images/graemlins/ooo.gif )

I had no idea about the 'slow cool' cure times or the reheating to keep the heads from cracking...
I always thought they were like casting bullets, pour the mould full and kick the bullet out! NOT SO!
(DOH! I can be so dumb sometimes!)

We've casted aluminum with a fair degree of success, but I suck at casting brass or bronze! /ubbthreads/images/graemlins/mad.gif
I tried to cast some black powder pistol frames and rings for black powder rifles and that was a disaster!
Might as well slept for a week, at least then I'd have been $100 up and well rested instead of broke, sweaty, exhausted and depressed!
There is some 'trick' to casting brass or bronze I'm just not getting...

I just start with a large block of yellow metal and make a small part and lots of shavings now!/ubbthreads/images/graemlins/cool.gif
Expensive, but at least the part turns out!
 

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Discussion Starter · #11 ·
Ijust recieved my Brass Expansion plugs from www.store.PartsDinosaur.com out of Phoenix AZ for $8.95 a set off of E-Bay ,, Plan on installing them this weekend ,,, Thanks for all your help ,,

Ill be driving my CJ before winter gets here... /ubbthreads/images/graemlins/smile.gif
 
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