Threaded Freeze Plugs...

[icanfixall]

Some time back there was issues with freeze plugs here. I had two pop out because the crappy shop installed brass plugs instead of the factory stainless steel. They didn't use the special installer either.. The second plug let go pulling a grade and I burned down that motor with 5200 miles on it... They gave me nothing about replacing parts... So I have been looking into a differant type plug and found it finally.... We can use a Boss 429 threaded 1 1/4 inch plug.... They are available on the Ebay site but... The block needs some machine work. The lip that the oem plugs sit in needs to be machined out. Otherwise the hole is already 1 1/2 inch diameter. The size of the drill bit needed or machining out the hole is 1 1/2 inch for the 1 1/4 inch plugs.... That works out in our benifit. The thread is 11 1/2 threads per in and tapered, not cut straight. This is really more than most could do for machining but some have access to the proper machine shop so it can be done but not easily for most

 

[sassyrel]

Some time back there was issues with freeze plugs here. I had two pop out because the crappy shop installed brass plugs instead of the factory stainless steel. They didn't use the special installer either.. The second plug let go pulling a grade and I burned down that motor with 5200 miles on it... They gave me nothing about replacing parts... So I have been looking into a differant type plug and found it finally.... We can use a Boss 429 threaded 1 1/4 inch plug.... They are available on the Ebay site but... The block needs some machine work. The lip that the oem plugs sit in needs to be machined out. Otherwise the hole is already 1 1/2 inch diameter. The size of the drill bit needed or machining out the hole is 1 1/2 inch for the 1 1/4 inch plugs.... That works out in our benifit. The thread is 11 1/2 threads per in and tapered, not cut straight. This is really more than most could do for machining but some have access to the proper machine shop so it can be done but not easily for most

while that be true, the correct soft plugs are cheap from ford--and rsdsl has the proper tool--and if that tool is used--i dont see how they would ever come out--

 

[lotzagoodstuff]

Is it a standard tapered pipe thread? Although as general rule I hate pipe threads in hydraulic systems, I think a tapered thread makes lots of sense in a low pressure/high vibration application like an IDI freeze plug. Some good thread sealant and they'll probably last forever.

Let us know what you figure out.

 

[Knuckledragger]

screw in core plugs?

I considered doing that when I rebuilt my 6.9, but the stock plugs and the tool were available. I wouldn't even think of it unless I had a bare block to work with because they are heavy beasts to start with, and you have very little room boring into the block before you hit cylinder walls. Of course, an accomplished machinist like icanfixall or an arrogant hack like myself can do the job, but only because we know exactly what we are doing. This is not a project to do while laying under a truck with a hand drill or sawzall. The tap you need costs about $153 (more than the rotunda tool to install the stock plugs), and you need to know when to stop cutting threads because the pipe plugs are only about 1/2 inch thick. An extra turn of the tapered tap and you have a junk block.

The stock plugs are similar to what was used on model A engines, so it isn't high tech. But installed properly, they seem to last and work just fine, even though it seems they should pop out at any moment.

I wold be interested in using a straight thread plug with an o ring or other seal on the block, but that calls for more machining and special tools plus a special plug to be made. Until I can buy the solution at the 99 cent store, I'm staying with the stock plugs.

 

[hesutton]

That sounds like a good way to keep them in the block, but I have a few questions. How do you get them in and out? I mean, is there a hex head on them? How would they function if the coolant were to freeze (I know that's not going to be an issue for you Gary in Southern Cali). Are they functional at all?

Heath

 

[icanfixall]

Here ya go Heath....
http://cgi.ebay.com/ebaymotors/Ford...om/ebaymotors/Ford-Racing-M-6026-B302-Freeze-
and another set..http://cgi.ebay.com/ebaymotors/Ford...r_Truck_Parts_Accessories?hash=item5ad4b6c0ea.

 

[hesutton]

OK, I figured they'd have to be key'ed or have a hex head on them. Those certainly wouldn't be functional, but they look like they'd stay put for sure.

Heath