Repairing a small hole in an intake port of a cast iron head....

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Hi all,I have a client who owns an auto repair shop.  He was porting the intake port of a manifold with a die grinder and cut away too much, leaving a small hole.  He asked if I could weld it shut.  The hole penetrated the water jacket.  The hole is about the size of the tip of a 3/32" rod.  My question is, what would be the best way to seal it.  It is about in inch into the port and reachable with a welding rod.My gut feeling is to clean it well and hit it with a spot of nickel rod.  My worry is that being that it was worn thin I might open up a larger hole.  My thinking is that if that were to happen, it would burn back to thicker metal leaving a larger surface to  begin sealing it up.  The engine is in the car and the manifold removed for access.I have never welded a cylinder head in this fashion before.  Is there anything I should watch for?  I would put a spot of weld down, let it cool, put another spot down, etc. until it is sealed.  I would not let it get hot.Any thoughts on This?  I asked the client to send me a picture of the hole but he hasn't done it yet so far.Thanks in advance,Tony                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 lllllll
Reply:Originally Posted by therrera The engine is in the car and the manifold removed for access.
Reply:That head will need lots of preheat, and controlled cooling in order to avoid a crack from your repair, if welded.Could the repair be TIG brazed? Head and intake temps on the intake side shouldnt reach more than 300-500 degrees at a maximum.
Reply:Thanks for the replies.  I think he saw the hole while doing the grinding.  Tig brazing is certainly an option I hadn't considered.  I think my main concern is how the metal would behave to the heat of even a drop of weld metal being applied.  I had planned on using a 3/32 ni-rod.  From time to time I use a technique that has worked for me in very thin situations.  I use a second electrode stripped of flux and let it drip onto the metal and then I fuse it.  The extra metal tends to cool the area briefly and prevents the burn through I want to avoid.  I have never attempted it on cast iron though.Do you think it would crack the metal even if I place just the equivalent of a light tack on the hole?   The thought occurred to me to go another route altogether.  There's a story involved but I'd like to share it.When I was about 18 I had a 1962 Renault Dalphine.  I overheated it one day and it started throwing white smoke out of the exhaust.  It was an aluminum head if I remember correctly.  I took the spark plug out the cylinders that was missing and a stream of water shot out into the air.  I thought the engine was shot.  At the time I didn't know enough about engine construction to realize that it was the head that was affected.Anyway out of desperation I went to the auto parts store and bought a pack of that aluminum powder stop leak.  I opened the radiator, poured the stuff in, started the car and let it warm up.  I swear to God that within a few minutes that stream of water that was shooting out of the spark plug hole slowly diminished until it was entirely gone!!! The stuff had sealed a hole or crack in the combustion chamber!!!I drove the car for two more years without any incident until the tranny went out on me and I junked the car.  I had purchased it at a city auto auction for $62 so I figured I more than got my money out of it.I am temped to tell my client to try that approach first exactly as I did and see if it works before attempting the welding approach.  What do you guys think?  I know it may sound cheesy to some, but if it works??Finally, I used this approach for another client here in Phoenix that had me weld (in position) a small hole that had developed on one of the heads on a V8 right near where the head is bolted to the block.  I sealed the hole, but in doing so the heat from the tig damaged the head gasket.  I had told him that this might happen but he figured he had nothing to lose as if it had to be taken apart anyway to fix it nothing was lost attempting the tig repair.    His business requires him to travel from Phoenix to Los Angeles weekly to pick up a load of batteries (he sells batteries).I told him about the aluminum powder sealant.  He was very skeptical but as I said, he had nothing to lose and he had to make a run in a few days.  I checked on him about a week later and he said that it worked fine.  He has been running it like that for four years.  I buy my batteries from him and sometimes drop by just to say hi when a service call takes me to his part of town.  We have since become friends and I always ask him how the truck is holding up.Any thoughts on it?Thanks,TonyLast edited by therrera; 07-20-2014 at 12:45 PM.Reason: to add calrity.
Reply:What about zinc rod with propane torch and sold out.   There are companies selling this as miracle welding rod via infomercials, but it's nothing special.  It's soldering basicallyTiger Sales:  AHP Distributor    www.tigersalesco.comAHP200x; AHP 160ST; MM350P,  Spoolmatic 30A; Everlast PowerTig 185; Thermal Dynamics 60i plasma.  For Sale:  Cobra Mig 250 w/ Push-pull gun.  Lincoln Wirematic 250
Reply:I think situations like this were the inspiration for JB weld.old Miller spectrum 625 Lincoln SP-135 T, CO2+0.025 wireMiller model 250 and WP-18V torchCraftsman 100amp AC/DC and WP-17V torchCentury 115-004 HF arc stabilizerHome made 4 transformer spot welderHome made alternator welder
Reply:If you strike an arc you will likely have a much bigger hole to contend with. Any other method will fail eventually. Time for him to bite the bullet and buy another head, and leave the porting to the guys who know what they are doing.
Reply:I'm not one to normally say this but run away from this.  Your client is a tool for porting heads installed in the car, on the engine and you can bet when his customer brings it back leaking you will catch ****.
Reply:Originally Posted by cd19I'm not one to normally say this but run away from this.  Your client is a tool for porting heads installed in the car, on the engine and you can bet when his customer brings it back leaking you will catch ****.
Reply:I wouldn't attempt on motor but.... if you are-expect to blow a bigger hole if you light arc on that thin area. I get many ported heads cracked because they are too thin to hold up under running conditions and they are a challenge! Welding on a few thousandths thick port wall is nearly impossible, but spray welding or brazing are best methods. Good news though, epoxy will work for some time in a intake port. No welding and a little Manley a b epoxy usually will seal intake port. From reading some of your past posts I understand you probably are going to give it a shot. Without proper preheat postheat and pressure test I wouldn't attempt but I do lots of these and guarantee my work.  PeterEquipment:2  old paws2  eyes (that don't look so good)1  bad back
Reply:Thanks for the replies.  I gave the client the forewarning that my attempt to repair it most likely will make a larger hole.  Castweld, given that your experience is that thin metal can lead to cracks in any case then even if I succeeded in sealing it, most likely the head would fail since the rest of the porting job would have thinned out the area too much.  I think you guys are right that I should not attempt it, at least not in position.  Taking it to a welder that has metal spraying capabilities would make more sense.  When I worked in the steel mills decades ago, I used metal spraying to build up shafts and worn parts.  I think it is the best solution.Given that, I will propose that he use the aluminum sealer to see if it holds as has been my experience and be prepared to pay for a head repair for the client when (if) it fails.  A man has to know his limitations.  I don't want to walk into a trap.Thanks,Tony
Reply:I missed that the first time. If they ported the head with the engine in the car I don't think you have to worry about it lasting very long.old Miller spectrum 625 Lincoln SP-135 T, CO2+0.025 wireMiller model 250 and WP-18V torchCraftsman 100amp AC/DC and WP-17V torchCentury 115-004 HF arc stabilizerHome made 4 transformer spot welderHome made alternator welder
Reply:Tony IIIIIII,I'm not a good enough tig weldor to attempt that type of repair. A good weldor has to understand their limitations. But I might attempt it by brazing with o/a; it doesn't blow holes.I say "might" as I haven't seen the repair area.Or I might use epoxy.My point is, only you know your limitations and capabilities.Also regarding the stop leak, there's much better stuff nowadays.  Spendy, but better.Lincoln SA 200Esab Caddy 160Thermal Arc 201TSMiller Dialarc HFI don't like making plans for the day because then the word "premeditated" gets thrown around the courtroom....
Reply:Hi dubl_t,The problem is that being cast iron, it will be prone to crack ON TOP OF the issue of blowing a hole in it.  Even torch brazing will require heating the area dull to cherry red wherein lies the danger of it cracking either upon expanding or upon contracting.  That's why it was suggested that this type of repair would require pre heat and post heat so that the entire part expands and contracts uniformly.  Not having that option because its in place puts the odds against my being able to successfully repair it and instead having it turn into a nightmare. I was hoping that quick tack welds could be employed heating the area only for a blink of an eye and not allowing it to get hot enough to reach cracking temperatures.  However because of the danger of it opening a large (larger) hole I would expose a larger area to heat and its resulting cracking danger in my attempt to close up the resulting hole.  Not to mention that even if I sealed it, a crack could develop because the port is too thin due to the grinding already done as castweld mentioned above.  That's why I think metal spraying is the best route to take but it will still require the head be out of the car.I'd rather avoid that scenario.  This could easily turn into an all day job if it goes south on me, and I might STILL not be able to make an acceptable repair.  Life is too short for the stress involved if that were to happen.However, having said that, what other types of sealers exist that could be used in this situation?  I am all ears as I would mention this to my client so he could explore that route.  I know the aluminum powder stuff works, I've seen it used this way twice already.  However this is a souped up V8 that operates way above the pressures and temperatures of a 60's vintage four banger where I first tried the stuff.  It might not hold up now that I think about it.  Please, do you have a brand name or manufacturer name I could research?Thanks,ToinyLast edited by therrera; 07-21-2014 at 05:10 AM.Reason: to ad more information
Reply:Z-spar Splash Zone is the most commonly used one that I know of for reshaping intake ports.  Epoxying of intake ports is very common in racing cylinder heads to relocate/reshape the intake side.
Reply:Yea Tony, I see what you're saying.  I thought the head, while ported on the car, was removed for you to repair.Re: sealers, look up Blue Devil, I got it at Napa. There are similar and maybe better, but that's what I used for a bad headgasket.Lincoln SA 200Esab Caddy 160Thermal Arc 201TSMiller Dialarc HFI don't like making plans for the day because then the word "premeditated" gets thrown around the courtroom....
Reply:Hi all,The last word on this project is that I told the client the reality he was facing and suggested two approaches.  One was to use the aluminum sealer I mentioned already and two was to pull the head and take it to a shop that is equipped with a metal sprayer.  He said he'd see what he can do.Thanks again for the feedback,Tony