Cracks between valves:S

[LoneWolf]

ive got the  head of my GTD, and it looks like its cracked between the valves on every cylinder :?

 is this a common occurance?

[bigblockchev]

This is very common. There is even a spec for it in the Bentley manual, too much and you turf the head, less than that it is ok to reuse. Generally less than 1mm is normal. Cracks in other areas are a different matter however. Cheers Dan

[LoneWolf]

mine are just between the valves.

 the car threw its coolant out of the exhaust, so i stripped it, and couldnt find anything wrong with the gaskett, so i rebuilt it with a new steel HG and set it up again, then it wouldnt run, but what it did do was to pressurise the coolant bottle so much that it split right open!

 i stripped it down AGAIN this morning and tahts when i noticed the cracks.

 is it safe to say that the heads damaged and thats whats making it blow up and not run?

[bigblockchev]

The coolant could be coming out from a blowthrough in the casting in the prechamber , this happened to me. The head looked ok on the surface but leaked when installed. Either way it is shot. You may be able to find a machine shop to pressure test it before condeming it. Cheers Dan

[LoneWolf]

so i could be better off putting in a new engine and saving the time really. ive got another head, but i didnt think about the block being damaged

[DCC]

so i could be better off putting in a new engine and saving the time really. ive got another head, but i didnt think about the block being damaged

Well, the cracks are very, very common. Almost every GTD head I've seen with some mileage had them. Have that head tested before arriving to any conclusion. Maybe the block is ok.

[burn_your_money]

Test what you have if it isn't crazy expensive. Who's to say the other engine won't have issues.