S4 rebuild questions
 

Hey, I've been slowly tearing apart my car to do a rebuild after the coolant seals wore out and i noticed the front side iron is cracked/chipped off at part of the water jacket. My motor is out of '88 N/A s4 it has about 130k on everything. I have been searching all over google, this and other forums for answers to a few of my questions about the build, but i cant seem to find much.

My first question: I am wondering if it is possible to fix and reuse the old iron that cracked, and if not then can i replace the s4 iron with an s5 iron(mostly curious because of price and availability of used parts).

My second question: regarding rotor housing and the wear from the corner piece on the apex seal. They are out of spec by Mazda criteria, however if i follow the guidelines from the rotary aviation rebuild video they are ok to use and may have good results, however he recommends cleaning up any gouges or peeling chrome with a dremmel tool. Is this necessary and has anyone done it? I have yet to find any mention of this anywhere. and if so, what dremmel tool would you use to clean it up with and prevent damaging the rotor housing?

If anything is out of spec it compromises the integrity of anything else.
If your housing has wear then your new engine wont have the optimum compression and will make the new seals wear into that housing pattern.

If the housing has damage then 2 things: get a new set or housing or a replacement that is within spec.
The one that is out of spec would really cost you ANOTHER rebuild in the long run,and it's cheaper to do that NOW,Once,rather than later.

Best bet is to post pictures. Far easier for us to make a judgement.

Mazda's chrome specs are very wide though...I think something like 1/4" of chrome flaking is acceptable. In my opinion that's way too much damaged chrome to accept as a usable housing.