Cracked Cylinder Head... Repairable/weldable???

[jmz]

In the process of having a 2.8 race motor rebuilt and this showed up... Builder thinks maybe it was torqued down on an uneven surface.

Any thoughts on if this can be welded up and repaired?

[JJK78-951]

The ones up top don't look bad but that big one, yikes! Not in an extremely sensitive area so I would think a repair is possible with the right skill set. Only problem is how deep is the crack and what kind of adverse effects could be caused by it. Worth it to build the whole motor with a questionable head or just replace it?

Personally I think it would cost less to replace it then to risk using it and having a problem, that is of course unless you are doing all of the work yourself and don't mind re-doing it, but I'm sure your builder doesn't work for free so... Cost of a new head vs cost of another engine rebuild?

Not sure I would go down the repair path, but hopefully someone with more experience will chime in with a more definite answer.

$.02
J

[jmz]

Originally Posted by JJK78-951

The ones up top don't look bad but that big one, yikes! Not in an extremely sensitive area so I would think a repair is possible with the right skill set. Only problem is how deep is the crack and what kind of adverse effects could be caused by it. Worth it to build the whole motor with a questionable head or just replace it?

Personally I think it would cost less to replace it then to risk using it and having a problem, that is of course unless you are doing all of the work yourself and don't mind re-doing it, but I'm sure your builder doesn't work for free so... Cost of a new head vs cost of another engine rebuild?

Not sure I would go down the repair path, but hopefully someone with more experience will chime in with a more definite answer.

$.02
J

...Thanks, part of the problem with replacing a head other than finding one is it will need to be twin plugged and then ported to match the other 5.

[JJK78-951]

Originally Posted by jmz

...Thanks, part of the problem with replacing a head other than finding one is it will need to be twin plugged and then ported to match the other 5.

Yeah that definitely sucks, but again, what is the cost if that head fails? Then you HAVE to replace the head AND rebuild the motor...

I'm lucky to be broke enough to not have those problems, but if it was mine, I'd replace it.

Good luck!
J

[jmz]

Originally Posted by JJK78-951

Yeah that definitely sucks, but again, what is the cost if that head fails? Then you HAVE to replace the head AND rebuild the motor...

I'm lucky to be broke enough to not have those problems, but if it was mine, I'd replace it.

Good luck!
J

Yes if it needs replacing for sure I will. I've sent a photo to Walt at Competition Engineering. He is not certain but thinks he could bandaid it up with a weld. I trust his skills so will probably send him the one head and then the rest if they will need to be resurfaced...

[JJK78-951]

Yeah Walt is the man to ask for sure! Like I said being in a non-critical area it seems like it would be OK. Hopefully Walt comes back with good news for ya!

[winders]

Competition Engineering? I can think of five places I would go before them and I don't like two of those.....

I would check with German Precision in CA or Extreme Cylinder Heads in Florida.

[jmz]

Originally Posted by winders

Competition Engineering? I can think of five places I would go before them and I don't like two of those.....

I would check with German Precision in CA or Extreme Cylinder Heads in Florida.

OK, All I know is that when I did my engine on my 3.0 a 10-12 yrs back Walt took good care of me.

[Tippy]

No expert, but I think that head is done. The fact the cracks propagates on a few different surfaces tells me its deep.

But, until you grind into the crack, it's a guessing game.

[911pcars]

I suggest getting the head crack tested, even x-rayed to assess the condition of the head. If okay, have it welded. CE and other reliable Porsche people will have the resources to get this done.

MHO,
Sherwood

[Henry Schmidt]

Originally Posted by jmz

In the process of having a 2.8 race motor rebuilt and this showed up... Builder thinks maybe it was torqued down on an uneven surface.

Any thoughts on if this can be welded up and repaired?

I can't tell by the photo but if it can be fixed, we can fix it.
If it can't be fixed, I have a plethora of core heads, the ability to twin plug one head and match the ports.
My guess is $250 (CIS head) for a core head, $200 to port the exhaust and intake and about $ 125 to twin plug one head.

These crates are full of heads......

[jmz]

Originally Posted by Henry Schmidt

I can't tell by the photo but if it can be fixed, we can fix it.
If it can't be fixed, I have a plethora of core heads, the ability to twin plug one head and match the ports.
My guess is $250 (CIS head) for a core head, $200 to port the exhaust and intake and about $ 125 to twin plug one head.

These crates are full of heads......

Thanks Henry. For what it's worth although I'm running carbs these ar MFI heads date coded 71. Not that imporant but I may at some point decide to do fuel injection so if I should have to start with a core head it would either be an MFI head or an MFI injection port added. ...wouldn't mind it to be a matching date code just for grins.

[Henry Schmidt]

Originally Posted by jmz

Thanks Henry. For what it's worth although I'm running carbs these ar MFI heads date coded 71. Not that imporant but I may at some point decide to do fuel injection so if I should have to start with a core head it would either be an MFI head or an MFI injection port added. ...wouldn't mind it to be a matching date code just for grins.

We have some MFI heads in stock and we can also add an MFI port to almost any head.
Send it and I see what we can do.

[304065]

That head is an ashtray. I bet Henry has a 71 head in that treasure trove.

[boosted79]

That head will make nice beer cans.