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Anyone successfully repair a cast iron head?

1084 Views 8 Replies 7 Participants Last post by  camachinist
Has anyone over ported an intake bowl to the point where he caused a pinhole into the water jacket and successfully repaired it??? I know that the correct answer is throw the head away and get another one. But because it is an intake there is no hot gases passing though under pressure. So if you used a liquid steel product and forced it into the hole so that it would spead in the water jacket enough to ancor it, and then spread a .060" layer a half inch or so around the area after roughing it up. Do you think it would work? Has anyone successfully (or not) tried it? What about welding?
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I would dnot try to patch it wils Liquid Steel, or any product like that. The only way to fix it, is to weld it. Take it to your machine shop, and let them make the decision....Putting a new motor together with a head that leaks is only asking for trouble....
I have seen several heads that were brazed up when that happened. It seemed to hold up OK. Brazing cast iron is a real art, though. It's way beyond my limits.

The only time I saw epoxy used, the hole wasn't into the water passage, so there wasn't any pressure on it. The first time it was done, the head wasn't clean enough and the patch came loose, causing a vacuum leak. It was patched again and held up until the car was sold several years later.
I'll probably get some flack from other posters but here goes...
If the hole is small enough drill and tap it, then smear on some JB weld on on a set screw and lock it down. Make sure you have no chance of it coming out, if there is not enough "meat" to hold the set screw then forget it. Welding might be the only option.
At least you didnt say you are going to catch "Flak".....

Im used to it though.
if I repaired a hole into the cooling of my motor I'd also consider KW block seal....seals BIG cooling breaches
If it is a valuable head it only makes sense to weld it. Check with shops that repair heavy equipment, they have blocks and heads welded a lot. There is a shop here in Tennessee about 30 miles from me that does excellant work (and who also happen to be Mustangers as well!). If it's just a run of the mill head, replacement is probably your best option.
I highly recommend Kelly's Block welding service in West Los Angeles. It's a family owned business, they have been machining my family's engines for 30+ years. Even repaired an aluminum cylinder head that was split into 3 sections.
Get another head unless this is a hi-po unit and you can't find one...IME, it's just not worth the effort, cost or time-wise, unless you have dozens of hours into the porting work and don't want to re-do another head. IME, furnace brazing is the best method of repair, but will require re-machining of all critical surfaces.

Even on a stock engine, the intake bowl area can get hotter than most epoxies can handle, long-term. Combine that with pressure and vibration and you have a repair that I definitely wouldn't send out with a warranty...*G*, especially in light of the fact that the underlying substrate had one pin hole and who knows how many others will pop up in that area...

If you are doing your own porting work (and I've done a fair amount of it), there is no substitute for cutting apart a junk stock head to actually see what you're doing and what the head looks like inside. It won't stop these pesky porosities from showing up, but should help keep you out of trouble otherwise...

Lastly, if you know the area is still thick but just got a pinhole, and the area can be accessed with a drill bit, you can drill out the pinhole and tap the hole and install a cast iron pin with sealant and then remove the excess pin material....I wouldn't do this unless I had a core head cut up to follow for the procedure...

Good luck!
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