ideas on freeze plug opening as water inlet/outlet port

Somebody has done it successfully, right?
How did you do it?
Rather not permanently alter the block, don't want it leaking, don't want it blowing out.
Links, ideas, pics, thinking out loud - all welcome

Thanks

 

Hemi, what if you used one of those rubber expansion plugs only instead of the bolth and nut you used a threaded fitting?

Just an idea.

Or what if you brazed a fitting into a soft plug then put the soft plug in place. You may need to glue it in with something like JB Weld?

 

Yep those are thoughts I've had. Just unsure of their success.

It's 1-5/8 BTW if it matters.

 

just tap the freeze plug hole like they did on the ford 427 and the boss 302's... I know you said you didnt really want to alter the block but if your idea of an inlet or outlet doesnt work then you just screw in a plug and be done.... just a thought

 

I kinda like trying a simpler, cheaper, approach first. You can experiment on an existing plug that is exposed; drill a hole in the plug, tap it slightly undersized and force a bushing or pet-cock in place. Worse case scenario is that it will leak and you get to replace it.

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The more invasive, the less options I will have.

 

I used to work on Detroit Diesels. One of the mods we used to make was putting a water feed into a freeze plug in the head. I think about an 1 1/2 dia plug, but that's not important.

What we did was make a slug out of mild steel, .001 to .002 over the size of the freeze plug hole. slight taper to get it started. But after that a straight sided plug. The ones we did had 1/2" pipe thread for an AN-8 line. But you could tap the center hole bigger if you needed. We used 1/4" plate to make the slug. If you used a larger pipe thread, you could increase the thickness of the plug to get more thread engaement.

These ran 7 lb pressure in the water jacket. Never lost one. I'd think they would easy run at 15 psi with out a problem. If one blew out, you could make a tighter press fit.

No modification to the head at all.

Frank

 

I would worry about a modified freeze plug getting twisted, or pulled loose by the hose attached to it. Maybe if you could braze an elbow or something to it, and use some nearby threaded hole to bolt it to as well.. might help take some of the strain off the press in plug to stay sealed ???

 

You want to come from the sides of the block to where?

 

Maybe a stupid question... but what's the purpose?

 

To get water in it out of the block, let's not complicate this thread. I promise ill start another one just for that issue.

 

It would be a 90* elbow & a length of hard line attached via brackets to the oilpan rail, then a hose.

 

I think just put a fitting into a freeze plug shouldnt be a big deal, NPT to 8 AN on a 90* should work fine.

 

I'd take a piece of 1 3/4" cold roll about 1 1/2" long and put it in a lathe and turn down a section on one end to what ever press fit size you wanted. The shoulder would give you a positive stop. Machine the rest of it to whatever you neded for a connection. If you had a convient bolt hole near by, build a retainer strap as well.

 

Vicky, they use similar methods to put block heaters in engines, it looks just like a beefier soft plug with the electric passing through it, and the heating element attached to the backside. I would say either the soft plug or making the heavier slug would work, but if you keep it as a soft plug, it will still work as intended if, heaven forbid, you ever did have the block freeze....

If you were going to machine a plug, consider brass, as it wil be easier to press in...

 

Nothing said yet about what block, exactly, is under consideration. From an EarlyHemi perspective, the oem 'freeze' plugs rarely "work as intended". I have a pile of broken blocks to prove their ineffectivness...

.

 

They are not there for freeze protection but to hold the core of the mold while the block is cast. The plugs are a cheap way to fill the hole left when the sand is removed.

Once water starts to crystalize (freeze) it expands in all directions. If you freeze a bucket of water you will see that it pushes out in all directions and splits the bucket insted of just raising the level in the bucket.

 

As Gary mentioned earlier, unless the inner step/stop is removed (assuming it is a Chrysler block) there is not much room to press in anything, let alone a plug of any type. How big of a line are you wanting to use?

Those who dont remember, these hemis use a disc type freeze plug. Once the center is driven in, you are not going to drill and tap with much success.

A guy could use one of the copper or stainless steel plugs that are held in with the T bolt arrangement. You would have to drill it, braze or weld the 90 on, and then bolt through the 90 to reach the T bar inside.

 

Here's successfully and how I did it. There are two Lehman water elbows for 1 1/4" hose in place of the two top plugs. Would have done the bottom two but oil filler tube was in the way of one of them.

Block mounted water pump was replaced with a crankshaft mounted pump with out put split to the two block inlets on the side.

 

Thanks guys !

The particular block this time for me is a 56 354 chrysler hemi. The ideas should be able to work on any block id think. Of course there's some particular things to the hemi like the ledge inside the hole to bottom the plug and I'm sure others.

I've never seen of of these plugs act as freeze protection either. Try to look them up by any other name and .....

 

Pontiac V-8's have what I think you are looking for. Passenger side head, rear most 'freeze plug' hole has a hose barb built in to it. I'm thinking these are 1" dia, but not certain.

 

solder your fitting into the expansion plug.
make a plug that holds an o-ring and a t-bolt for a retainer.thread pipe fitting off centre.done.