Is this head repairable?

[turbogrill]

Hi

 

There is a crack in my N47 head in a coolant passage.

 

Can it be repaired?

 

Crack is marked with red arrow.

[BluDestiny]

Any idea how deep it goes? Have you put some dye and a black light on it? 

[seattlejester]

Depends on how far it propagates. I'm not sure welding would be an option given the location. Maybe some compound could be used, or maybe a sleeve, but without knowing how deep it goes down or how far it goes back can't give a solid answer.

 

Unless there has been a lot of work done to it, it may be easier to find another N47

[turbogrill]

Hi,

 

 

Any idea how deep it goes? Have you put some dye and a black light on it? 

 

I haven't! Didn't know that was a thing. I have tried to look at it with a flashlight but it's very tiny.

 

 

Depends on how far it propagates. I'm not sure welding would be an option given the location. Maybe some compound could be used, or maybe a sleeve, but without knowing how deep it goes down or how far it goes back can't give a solid answer.

 

Unless there has been a lot of work done to it, it may be easier to find another N47

 

It has a nice port and valve job. 

 

I will have an "expert" examine it, maybe it will justify the cost to fix it. Otherwise I might sell a kidney and get a P79 shimmed, shaved and ported.

 

It's for my crap can race car, so it's a budget racer but still a racer. So it will see high RPM for many many hours non stop. 

[seattlejester]

Hmm I'm just not sure how a deep hole repair like that would go. On an iron block or head I believe the standard practice is to grind it all out and build the material back up via welding, but welding cast aluminum is quite tedious even to begin with (not that welding cast iron is easy). 

 

Would be interested in what an expert has to say. I know my local machine shop offers repairs for things like iron heads and blocks, but I don't recall a similar offering for an aluminum head.

[TimZ]

Hi

 

There is a crack in my N47 head in a coolant passage.

 

Can it be repaired?

 

Crack is marked with red arrow.

How deep does the hole go?  It's just a coolant passage and it likely opens into a larger coolant passage inside the head.  At the surfaceit looks like the crack doesn't run very deep - if the hole doesn't run real deep you could likely take a die grinder with a small carbide bit and just grind the crack out and leave the hole oblong.

[turbogrill]

How deep does the hole go?  It's just a coolant passage and it likely opens into a larger coolant passage inside the head.  At the surfaceit looks like the crack doesn't run very deep - if the hole doesn't run real deep you could likely take a die grinder with a small carbide bit and just grind the crack out and leave the hole oblong.

 

Interesting, so basically just grind the away the crack?

 

The coolant passage will be a little wider at that point, but maybe that doesn't  matter?

[TimZ]

Interesting, so basically just grind the away the crack?

 

The coolant passage will be a little wider at that point, but maybe that doesn't  matter?

Yes, exactly.  You have to get all the way to the root of the crack for the length of the crack, though.  This will eliminate the stress riser and stop the cracking.