Unpleasant surprise

[Frango100]

When i took the starter motor out for rebuild, i had seen some strange looking surface on the engine block behind the starter motor. There was a bit of coolant leak from there, which i thought was the freeze plug. Yesterday i discovered that the strange looking surface was a kind of repair of the engine block with some epoxy stuff. I took that stuff of and didnīt see any crack, but they had cut a shallow groove in the block where after a while, the area is becoming slightly damp. So there must be some kind of crack in there. Looked for a good repair method for this, which doesnīt seem to be that easy.
Do you guys have any good experiences with stop leak stuff? I red about clogging heater core (which is bypassed on my bird), but what about clogging the radiator? (which is new)

[jopizz]

I've used various stop-leak products in the past to seal pin holes in the radiator with minimal success. As you mentioned they can cause blockages in your radiator. I don't know of any product you can add to the coolant that will seal a crack in the block. Sealing cast iron is much different than sealing thin copper or aluminum. Even if you could get good access, welding cast iron is tricky. You may be better off just trying to reseal it with a good waterproof epoxy and hope for the best. I've used J-B Weld for a number of different projects and it works very well. I would recommend draining the coolant from the block so the crack is completely dry. If you were here in the states it would be easy to find another FE block but I'm sure they are at a premium where you are.

John

[OX1]

This stuff welded a lower bellhousing "ear" (half of it anyway)
on a later model 302 block. I busted the outer edge
of it off, mounting block to engine stand with an off center
"tube" from stand, using an air gun.

Anyway, welded cast as easy as I usually weld mild steel.
Usually cast iron needs to be stick welded, but I'm
much better with a MIG. Not cheap, but neither is a
new engine.

https://www.ebay.com/itm/Crown-035-x-2-ROYAL-44-30-ER-NiFeMn-CI-MIG-2-lb-SPOOL/141713757642?hash=item20fecc55ca:g:zqAAAOSwPcVVnXBH

[sidewalkman]

Use a 2 part epoxy, never EVER use a stop leak product in your coolant. It does not discriminate between water journals in the radiator or a leak and plugs them all. I can't tell you how many people I know including myself that have seized a motor through overheating after using that crap. I don't understand how they can still sell it.

[Frango100]

Thanks for the answers guys. A new block would be a very rare find, not many cars where imported those years, so finding one is almost impossible. And if there is one, it would cost a fortune.
I used some epoxy on it, lets see how it will hold. I have the car a bit more then a year and didnīt see any drop from there before, so the old repair did hold for quite some time.