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Q - screw-in block core plug removal
#1
OK. older style coreplugs. A block which I feel like fiddling with to learn how to do things I haven't attempted.
What is the best way to remove the external core plugs with the slot in them... assuming they have been there a long time. Someone mentioned replacing with brass ones?
This block also has the little ?brazed/soldered extra plugged core holes at the ends of the valve area. 
Are these something worth disturbing for a clean up inside - or leave well alone?
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#2
I find that with most things that are tight and corroded in heat is the best way to assist removal provided there is nothing within them that may burn or catch fire. Anything aluminium should be heated slowly and with not to much heat to prevent distortion.

John Mason.
Would you believe it "Her who must be obeyed" refers to my Ruby as the toy.
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#3
Are these large slotted screw-in core plugs available form A7 suppliers?
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#4
I think these screw-in plugs are best left alone. As far as I know new ones are not available.
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#5
One leaked once, on the block still on the RP (P.S vintage blocks are better metal than later ones). We sealed the leaak with silver solder.

That was 30 years ago
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#6
I would leave them alone, you will do more harm than good. Heat would probably work but not worth the risk.
If you want to get it clean inside submerge it in BiltHamber for a week or so
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#7
I'm with david and gene.

Leave well alone.

I dont think suppliers have new ones, so if you damage the originals, you are into the cost of one offs.

But if you must, just for fun. 

And you damage them.

I'll own up just for this one job, and say If you find what the threads are. Im 90% sure I can get replacement plugs of the shelf.

Tony
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#8
no - very happy to go with professional experience! I need to know where the boundaries are and now I do.
So old blocks - leave be. Newer blocks - do the core plugs as you never quite know how thick they are, right?
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#9
I found a new screw-in plug in a lot of spares years ago - it is 1¼" x 16 tpi. However, it did not come out of a block so I can't guarantee that it is the correct one for the early blocks. The OD of the outer part is 1-9/16".
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#10
I don't think you stand much chance undoing/removing them.I've only done it once and that was by setting the block up on the milling machine,machining the head off then carefully drilling the threaded part out and loosening the bit left with heat and penetrant.
Then had to make the replacement plugs,I think  1 1/4 x16 I think.
The worst part for silting up is between the cylinder core and the tappet chest which is impossible to clear.The only time you can see how bad it is blocked is when you cut the block up.
Someone has suggested molassis previously ?
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