Rotor Weight and Spotted Iron
 

Not a builder so consider this as much of a bump to the top as any thing but....IIRC you can be off one letter either way on weight. So you should be OK if they're both the same and both from a tubo engine.
It looks like a casting flaw between the coolant seal grooves. Is that what your referring to? If so and it does intrude into a groove and is not raised I think your OK there too.

I would double check your rotor to make sure it is a duplicate sounds like its way out for weight balance ., check out the Pineapple Racing video about rotor weights..........the.damaged water jacket piece is usually caused bye a slight core shift which leaves a small casting on one side of the Iron to support the compression seal.. under heavy use or abuse,or (overheating, plugged cat,etc they can crack and blow out, allowing compression to leak into the water jacket and force out your coolant.. Toss out the broken one,it's.Time for another Iron ..........

Dang that's not what I wanted to hear. Is there any way to fill back in the casting?

Not really ..I would cost to much to weld it them machine it ..throw it away and replace it with another ...good one ......

i don't see anything wrong with that iron, and the rotor will be fine if it is letter matched. yes there is variances in weight but 55grams is nothing world crashing for a rotary engine. if the engine is being built for over 9k RPMs then yes, it should be balanced otherwise leave it alone.

Looks like dremel slip on that iron lol. But I'd get the rotor balanced/matched to the other one if it were me.

After having another look(must have had my glasses upside down) as long as there is no damage to the water jacket seal or comp seal and the casting is lower than the Rotor housing face it should be fine..sorry for the scare...

:icon_tup:

Thanks guys for all the help. I will plan on reusing them then.

similar question, can you save a iron with inner water jacket seal failure by using epoxy?

no, it must be welded to repair the water jacket. epoxy or JB weld will not hold the pressure that the wall sees.

if it is a stock iron then you should just find a replacement. if it is a ported iron and you want to save it or an iron that is difficult to replace like an RE cosmo iron then they can be repaired. i do sell sleeves for broken irons but still recommend repairing the break and is something i can do for $100 per break. the iron seal sleeve set and coolant seal set is $165.