3b head crack

[bizzjet]

Im just come from the head shop. Here the result. No leak from pressurise but crack between valve. I got two other head and found the same on one or two cylinder. If someone knew if those crack are dangerous?

tks

 

[amaurer]

cracks there are VERYY common for 3b's.

Opinions vary, but if it passed a pressure test I'd run it. In fact, I AM running a head with the same cracks.

I think its pretty easy to swap a head on a 3B so I'd gamble and perhaps save the $700 for a new head.

 

[VTCDN]

Those are a semi normal crack that I have seen.
Some engine Manufactures allow specs of .XXXXX max allowed , and trying to measure a crack is done by a Tweaker gauge ??

As amaurer posted , Run it with a steel head gasket. Pre Cups look good ?
gerg was / has a fuel pump . Hope you got the e-mail ..

VT

 

[gerg]

I am into my second year with a head with identical cracks in each cylinder to yours. I plan on changing my head for a new one because of it though.

Given how I have pushed my engine with egts, boost, overheating... and it still passed the last pressure test... Id say these cracks progress fairly slowly. I am of the opinion that cracks, once started, don't stop until they hit an opening... like a jacket or journal, or the other side of the head.
g

 

[gerg]

If there is even the slightest cracks in the pre cups id change them. Actully id change them even if there weren't any unless they were recently replaced. John at Raddcruisers has these for a good price and is super fast with shipping.
g

 

[DieselCruiser81]

Cracks

My head had close to identical cracks and I kept having overheating issues. You could see that it had been causing problems once I pulled the head off. A local machine shop fixed the head and my overheating issues seemed to have stopped.
-Chris

 

[bizzjet]

i decide to use a other head a got in my shop. I was supposed to sell this head show on picture to a guy but he decide to not take it since crack was discover... But in meantimes i have to repair my bj70 that got a explode connecting rod bolt failure. So i put a new block in my bj70 and send the order head i got here to the same head shop. Surprise!!! the other head have been repaired and all the crack have been filled (stich repair). Why install a cracked one if i got one already repair!