A crack in an exhaust port = useless head?

[eraezer]

Hello,
when I started porting my exhaust ports today I found a small crack What do I do now? Is the head useless?

Here is a picture:

 

[bioskyline]

id clean it up and sand that area a bit (ie start the port and polish process) and see if its just a surface crack or if it goes deeper. could possible be welded. if not then it will need to be replaced.

 

[suprarx7nut]

Clean it up and take another pic. Hard to tell anything from that one picture.

 

[eraezer]

the port process started before I took that pic. So I have already tried to grind it down.
The ports were black before and that's why I didnt see the crack until now.
The crack continues out to the manifold mating surface and stops where the black ring stops.
I'll try and take a better pic the next time.

This is bad news

 

[Typhoon]

Worst case, it will weld up easily. Given that it's at the edge of a casting, it will both be easy to prepare and weld and not introduce any real stresses into the casting. So don't stress out about it. If you get it welded, you can get the manifold surface machined too.

 

[hvyman]

Could be signs of a weak head. Migh be better to find another one. There not much either.

 

[eraezer]

hvyman, that's a good point.
Since I'm spending a lot of my hard earned money (still in school, working mostly during the summer break = not so much money) I don't want this to fail due to a shortcut.
I picked up another head yesterday which is in far better condition overall and no cracks But the exh. studs are thrashed, so they will be helicoild.
I will keep the old head and weld it myself when I have access to some better equipment.

 

[MRSUPRA]

A good machine shop can fix it properly. Just be prepaired to spend $$

 

[Typhoon]

I wonder how many here have any actual experience with anything to do with engines? It will cost $40 or so to get that welded and another $40 or so to have the exhaust face machined.
As for a sign of a bad head, nonsense.

 

[NashMan]

I fixed mine cracked right under the valve seat


just have to grind it all out and weld then ball peen the slag out of the weld then re weld ball peen slag repeat tell done.


I have pic' of mine getting done it's in my build thread

http://www.supramania.com/forums/showthread.php?74680-Ryan-s-92-build-thread-aka-NashMan/page40


ps the only reason why I did this was my head was ported and had brand new cut vavles and stuff


cost was alot less then yours will ever be

 

[radiod]

I'd get it hardness tested to see if the head has annealed. Granted, the exhaust ports are going to always be the worst, but not a bad idea to get the rest of it checked out. Last thing you want is cracks between the combustion chamber and coolant passages .