I have a LT1 aluminum head that has a cracked exhaust port.

Took it to get welded and they could not get the torch into the port very well due to the angle/position of the crack, also the metal was thin around the crack so a penny size hole opened up.

They covered the opening with a few beads and pressure tested the port, a few pinhole leaks were still apparent.

Now they put a aluminum repair compound under pressure and forced it into the holes, and are baking it into the head to seal the port.

I am concerned about the durability, anyone with similar experiance/comments?

 

I would keep your eyes open for another set of heads (or head).

 

Sounds like good time to upgrade to set of ported heads with a hot cam. If cracked in area of thin metal already I am willing to bet prone to cracking again, especially since cannot get welded up. Besides, money you are spending to get heads fixed right now could probably get a used set for same or less. Good luck.

 

These are ported heads

 

i have a stock set on ebay right now, pm me interest.

 

Time for some new heads as even if they were able to get in there, no telling when it will let go with the vibrations and heat cycles of your motor. Cracked head = replace in my book.

 

I'd rely on a competent machine shop to tell me if it's best to try to repair it or or to junk it. I don't agree that a crack necessarily = junk. It depends where it is and what the head is. Most any crack CAN be repaired, but it could way too time consuming (= expensive) to do so.

Rich

 

Welding in ports is not fun, a lot of the time you need to grind yourself a pathway through the start of the port to get the torch in there, then weld it back up on your way out = $$


The Seal Coat they are using is good stuff - I have used it in the past quite a few times for weeping BBC exhaust guides and after extensive welding and pin repair. I have not tried to use it where the leak is in an exhaust port and I would be a little apprehensive about using it there.

 

I had one of my exhaust ports developed a leak at the end of last year racing season. I took it to a guy that does very very good job of welding. He was able to get it welded up and so far no leaks. It started out as a pinhole leak and then a small crack started to develope. I do remember that when he started the repair the hole got bigger then he started his magic of filling the hole back up.

I'm hopeing that these will last through this racing season so I can get some different ones, might go to aftermarket heads.

Cost wise it was not bad at all he was a good friend of a friend type of deal.