Cracked Heads - can these be fixed?

[mcandmar]

First off the ABY head from my project engine, had a helicoil installed (rather badly) to fix the no3 spark plug threads in a previous life. BUT ot has three large cracks around it so i take it thats a total bin job

[mcandmar]

Then i turned to my spare head off an AAN to find it has a bloody crack in it too

[mcandmar]

Is there anyway at all these are fixable? Looks like my ABY project has fallen flat on its face so i'm off to cry into a beer..

[Jamo]

Those cracks are common on the ABY / AAN head.

Search for SteveH threads on heads he's had the same trouble and had them fixed can't remember where though.

[Mark Halligan]

From the AAN repair manual:

Cylinder heads with cracks between valve seats or between valve seat and spark plug threads may be reused without reducing service life, provided cracks do not exceed 0.5 mm (0.020 in.) width, or when no more than first threads are cracked.

I have seen these cracks welded and ground before (on one head anyway). While your at it it if your not happy with the helicoil you could have it replaced with a T-cert.

[Mark Halligan]

more info

http://www.s2forum.com/forum/showthread.php?t=7400

[porkkis]

I've used a cracked head for about 70kkm now. It was and is pretty bad. No problems whatsoever.

[mcandmar]

Thanks guys, i'm not as freaked out now after reading those threads. The cracks dont seem to have moved down the plug threads or the valve ports so i may just leave well alone by the sound of things. Bit of a polish up and cross the fingers

Thanks,

Mark.

[mcandmar]

Its a junker, has a crack about an inch long down one of the exhaust ports

[WabTheKing]

http://www.cast-iron-repair.com/

try these guys they repaired the cracks in my head

[mcandmar]

Thanks Will but i just don’t think it’s worth saving to be honest. I was going to replace all the valve guides, lifters, valves, 3 angle valve jobs, port and polish etc etc. I'm just loathed to spend a grand rebuilding a head that may cause problems down the road. Would rather get a clean head (without a poxy helicoil) and put the money into that.

[WabTheKing]

i have a 7A head for sale

[Puglife]

the cracks are common due to the heat and distance between inlet and exhaust valve... very common and even new heads will crack after a hundred miles or so...

as long as its only small don't worry

[mcandmar]

I had thought of using my 7A one as its had a port and polish already, just seems like a PITA to get the water manifold and cam sensor mounts machined on it. I'll reserve that as plan B.

@puglife: The crack is about an inch long, on the above pic is the top left crack from the spark plug threads to the exhaust valve, then runs down the exhaust port about an inch. I suspect it had been leaking before i bought the engine

[WabTheKing]

I had thought of using my 7A one as its had a port and polish already, just seems like a PITA to get the water manifold and cam sensor mounts machined on it. I'll reserve that as plan B.

@puglife: The crack is about an inch long, on the above pic is the top left crack from the spark plug threads to the exhaust valve, then runs down the exhaust port about an inch. I suspect it had been leaking before i bought the engine

if you have one to copy its easy! you need a man with a milling machine!!