a racing buddy of mine has a set of bulldog heads on his duster that have had issues with porosity. specifically, one of the exhaust ports is seeping coolant. he's had it welded, and it's seeping again, in the bowl area. his welder said it's not repairable this time. do any of you guys have any experience with this problem? any "miracle cures"?
Posted By: dOc !
Re: ALUMINUM HEAD POROSITY - 08/17/11 07:19 PM
There is a 3 step stop-leak process that I helped a friend with some years back. It stopped a head-gasket leak ...so it should "cure" a little porosity.
Posted By: mafo
Re: ALUMINUM HEAD POROSITY - 08/17/11 10:19 PM
Goodson sell a very good product called SEAL ALL block and head sealer, works for me
Posted By: POS Dakota
Re: ALUMINUM HEAD POROSITY - 08/17/11 11:18 PM
I saw a thread on this subject on speedtalk forum a while bck and there was some good useful info on this very subject. Might be worth checking it out. I remember several concotions being mentioned. One thaat's poured into the head then I think baked. Forgot what it was called though...
One of the brands was called "kreme" I think.
Posted By: B G Racing
Re: ALUMINUM HEAD POROSITY - 08/17/11 11:22 PM
Sometimes it is to thin in the area to weld,we usually lightly peen the area with a round head punch and rub some high temp Lab Metal or similar into the porosity holes.Them we put a sealer in the cooling system,usually Dyke or other sealer.
Posted By: HEMIFRED
Re: ALUMINUM HEAD POROSITY - 08/18/11 12:11 AM
We had a B/B that leaked coolant into the oil from what was thought to come from the head. it was found that it leaked only the engine got hot and pressure in the radiator rose to 14lb. No way would it stop everything was tried with no luck until the coolant was replaced with EVANS which does not boil until 370 degrees. so it never got that hot and only a zero lb cap on the radiator. last chance repair is still working
Posted By: Twostick
Re: ALUMINUM HEAD POROSITY - 08/18/11 02:53 AM
Try some Waterglass
http://en.wikipedia.org/wiki/Sodium_silicateOld school cure that is cheap and effective.
Kevin
Posted By: 40ford
Re: ALUMINUM HEAD POROSITY - 08/18/11 03:02 PM
We have dealt with cylinder head (and block) porosity for years---starting with W2s that had been ported too far. And W5s, early Arringtons, W7s, and even the aluminum sprint blocks. We found the best repair was to carry the problem part(s) to a full line cylinder head repair shop. There, they use a waterglass solution, under pressure, heated to stop the leak. Sometimes, the treatment only takes one hour, sometimes the treatment requires eight hours---but it has always gotten repaired. You probably will need to make your own block off plates for any heads(18 or 20 heads).
And, you get the advantage of better heat retention in aluminum heads=====better horsepower.
a lot of good info here. thanks all!
.... 
...