Cracks between spark plug and valve seats?

[A_J_T]

One of my heads has cracks on both spark plug holes protruding towards the valve seats. I’ve been reading around about this issue and it does appear to be rather common.

http://forums.nasioc.com/forums/showthread.php?t=2012107

http://forums.nasioc.com/forums/showthread.php?t=2269015

http://forums.nasioc.com/forums/showthread.php?t=2435567

What are everyone’s thoughts on these apparently common cracks? So far my options appear to be ignore and continue or find a replacement head/s.

[Rosssub]

The version 7 STI heads that sold on trademe last week had the same cracks. Getting them pressure tested should let you know if they'll cause issues or not, hot compression loss etc.

[Guest]

Just twist brians arm for the v8 sti longblock...get an ecu and play happy families. Ive probably got all the loom plugs you need for conversion.

[A_J_T]

 Rosssub']The version 7 STI heads that sold on trademe last week had the same cracks. Getting them pressure tested should let you know if they'll cause issues or not, hot compression loss etc.

So providing they pass testing you would use them? feels so wrong, somthing like that could/should only get worse?

[quote name='evowrx said:

Just twist brians arm for the v8 sti longblock...get an ecu and play happy families. Ive probably got all the loom plugs you need for conversion.

Yes this will happen one day just not today haha, i do not have the coin.

[kamineko]

 A_J_T said:

feels so wrong, somthing like that could/should only get worse?.

sigh, this exactly. almost wish i never noticed the cracks in my RA heads. bought some G heads to replace, went to lots of trouble etc only to find the replacement heads i've been working on have fine cracks as well

what do you do?

[Rosssub]

 A_J_T said:

So providing they pass testing you would use them?

Yip, if they pass. Chances are any replacements of the same model/casting will be the same, or end up the same.

[Guest]

Common in v7 sti avcs heads.

[pedro]

Seen a lot of 4 valve heads on bikes and cars that have cracked like this..Never had any problems using them and never personally seen one drop a valve seat..But always in the back of the mind knowing things aren't quite right..

[hijacka]

Common in v5-v6 heads as well, your old heads had cracks in them to clint, not all cyl just 2 but i'm using them without issue(haven't comp tested but runs fine), i would probably get them checked by a head specialist if the crack had effected the valve seat though wouldn't want it to fall out and i would say compression would be effected in that case.

[A_J_T]

Cool cool, ill get them pressure tested and if all comes out ok ill slap them back on and forget i ever saw the cracks.

[Minaj]

I had cracks in mine and it worked out fine no problems, just the dropped valve problem atm due to some other circumstance lol.