Sealing porous heads?

[TRDirks]

I have recently aquired a set of M&A heads. Upon pressure testing it was clear that they have a porousity problem. there is a total of 6 leaks between the two heads. All but one of the leaks are external with the one leaking under the valve cover. All of the leaks have been attemted to be repaired by a previous owner via either welding or apoxy unsuccesfully. I have heard about GM tablet sealer and K&W sealer which both would be done after install. A freind mentioned some type of ceramic coating that would be poured into the coolant passages, adhearing to the inside of the passages and sealing from the inside. Do any of you know about this procees? What is it and where can I get it done? Is there any other type of sealer or process (permanent) that can be done to fix the porousity of the coolant passages with the heads off the car?

TIA

 

[Wicked]

I wouldn't use them, especially with a leak in valve cover area. I saw this on a set of champions years ago.
Champion couldn't even seal the heads. After debate due to champion not wanting to send a new set of heads they finally sent a new set to him. His leaked externally around the exhaust ports. Just an expierience and my 2 cents.

 

[Jeff Rand]

I had a stage 1 that was cracked at the freeze out plugs and I used a ceramic sealer that worked very well. Below is the web site. (Cost is about $12 and it is easier to use vs the KW product)

http://irontite.com/adds.htm
Good Luck,
Jeff

 

[TRDirks]

Jeff,
Is that sealer put in to the cooling system after assembly? I would really prefer to seal them off of the engine somehow. That way I could pressure test and be somewhat confident of the results.

Anyone else have any idea's?

 

[Jeff Rand]

Originally posted by TRDirks
Jeff,
Is that sealer put in to the cooling system after assembly? I would really prefer to seal them off of the engine somehow. That way I could pressure test and be somewhat confident of the results.

Anyone else have any idea's?

Yes, this sealer is placed into the engine after assembly.
Jeff