Aluminum Cadillac Engine Block ?

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A customer asked me to weld this in the car. Well thats impossible, cant get to it. He said he could get it pulled out and then I could get to it. But, before he goes that far I thought I'd ask and see if any of you have had or heard of people whom have had luck welding a Northstar engine. Appreciate any help good or not good.
Reply:We had a cast 4.3L V6 block welded on the outside.  Unfortunately we later found out that more times than not once they crack on the outside they also crack on the inside- once we got it running again (swapped it into a 1977 porsche) it was shot and required rebuilding.Also do you know what alloy the block is made of? I am new to aluminum but if I were to guess I would say it would be 5xxx series maybe 5052?? I would do some research to find out exactly what it is as an engine constantly sees temps above 150 degrees and neither 4043 or 5554 filler material make strong welds in 5052 and are required for that temp requirement.  If it is 3xxx series like 3003 4043 would be a fine choice... Also remember wherever you weld you will revert to 0 temper strength so if that block had heat treatments done to it for strength they will be gone in the area of the weld and maybe more the more heat you put into it.  You are going to need a lot of heat as well to weld an aluminum block as it is so large it is going to dissipate lots of power.  I wouldn't make any promises unless you have welded a lot of aluminum engines as he will probably need a new short block regardless of what you do as I mentioned before if its busted on the outside its also likely busted on the inside.Last edited by hpfiend; 04-06-2009 at 01:39 PM.
Reply:I've checked with a GM dealership about the alloy but can you imagine they can't tell me the alloy. A Lincoln rep. gave me some hints on how to narrow that down but,I don't feel thats good enough for such an instance. The 0 temper thing you mentioned raised an eyebrow though. Thanks
Reply:I am by no means any kind of expert at cast aluminum welding, but I do it once in a long while.  One job, I tried to weld a cast aluminum heavy duty truck tranny housing and it turned out to be a mess.  Not enough power from my TA185 for that much mass of aluminum and the casting was very very dirty and porous.   I warned the customer before hand that I might not be able to fix it, so he wasn't worried about it when I called and told him it was a no-go.   The crack was all the way through the case, all the way around the bell housing, it was practically in 3 pieces when he brought it to me, so it was a lost cause before I ever touched it.MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op
Reply:There are folks here that have welded up aluminum blocks before and they will probably give you some very good advice on how this can be done, but I will bet you that you'ld have to pull the engine, disassemble it and clean the snot ouf of it to get is done correctly.  Do you suspect he is trying to patch it up for the NEXT buyer?Smithboy...if it ain't broke, you ain't tryin'.
Reply:Originally Posted by smithboyDo you suspect he is trying to patch it up for the NEXT buyer?
Reply:Originally Posted by Craig in DenverMan, that would suck!
Reply:Originally Posted by smithboy. Do you suspect he is trying to patch it up for the NEXT buyer?
Reply:All the alloys mentioned so far are wrought aluminium, cast Al uses a different designation system. Cast alloys most often encountered will be silicon rich (ease of casting + some other reasons)...aluminium-silicon casting alloysThis has been discussed a few times before on various forums... I think general consensus was that the alloy used was A319-T5 (Al, Si, Cu alloy), with A356 being the other contender. I can't remember if it was the northstar specifically that was being discussed or an LS6 (which IS a319-T5) thoughLocation of the crack(s) is going to play a big role in deciding if repair is economic- if the crack isn't completely removed it'll just grow back.
Reply:Good point hotrodder- I wasn't lying when I said I was new to aluminum ;-)However if I am reading my chart correctly, if it is a 319.0 alloy with T5 treatment meaning it has been artificially aged.  I am not sure what the heat from welding will do that or how to duplicate the artificial aging in the welded area as I am not sure how that procedure is done.  It cannot be o/a welded.  It can be flux or inert gas arc welded in most applications.  You will need to use either 2319 or 4145 filler allloy (4043/4047 will not work).  For crack free easy welding 4145 is slightly better (A versus B rating) but has less strength, ductility, and corrosion resistance than 2319 (all Bs versus As)- both are suitable for sustained temps above 150.  If it were me I would probably use the 2319.  I have never welded cast aluminum yet but I have been told that you need to v-groove it in the area that is damaged until you get to clean metal under an arc.Hope this helps,AndrewLast edited by hpfiend; 04-07-2009 at 01:31 PM.
Reply:Depending one what the crack is.   if its just a coolant leak all you need to do is spackle over the top of the crack to hold water.   If its some thing structural then your going to have issuesVantage 500's LN-25's, VI-400's, cobramatics, Miller migs, synch 350 LX, Powcon inverters, XMT's, 250 Ton Acurrpress 12' brake, 1/4" 10' Atlantic shear,Koikie plasma table W/ esab plasmas. marvel & hyd-mech saws, pirrana & metal muncher punches.
Reply:The crack is a bolt hole about 1 to 2 " deep. Sorta as if some body overtightened a bolt and snapped the casting. But, in this case a belt broke ripped the pulley off and the cast. Appreciate all the info fellas !
Reply:I've welded quite a bit of cast alum. just did the side casing on a sportster on the bike! Done outboard boat motors and props as well, and I've found that 4043 works fine. You do have to "V" it out as much as possible and clean with solvent and wire brush any oxide from weld zone. As far as the location of your particular situation, Good luck!
Reply:There's at least one thread in the pics and projects forum showing a similar repair, may be helpful. IIRC poster may have been Castweld?What that Alcotec filler selection doesn't show is the filler chemistry (there are more detailed pdfs for the various filler alloys on the site). 2319 has very little silicon, 4145 is a much closer match if the block is 319...Artificial aging 319.0 (from 'as cast') would be something along the lines of 8 hours at 205C for a T5 temper. Welding heat treated alloys typically results in a combination of annealed/partially annealed areas and over aged areas in the weld and HAZ. Annealed/partially annealed areas will make a partial recovery with time (varies with different alloys) which can be improved by artificial aging but aging has little effect on overaged areas. For something simple like a bolt hole lug my approach is usually to minimise the amount of overaging that occurs- a gentle preheat to keep the temperature gradient sensible and minimize the heat input.
Reply:AH now that I know the whole situation. I too had a similar problem but mine was with a bolt that was galvanicly welded into a front accessory cover on a diesel.   even after soaking the bolt with every known spray on earth the housing still galled and broke out when I tried to remove the bolt.  Easiest fix without taking the entire front gear train off the motor was epoxy a piece of metric threaded rod into the accessory drive housing and use a nut to secure the oil cooler header.   put 100,000 more miles on that truck and its sitting outside right now.   still holding strong.Their was JUST enough of a remaining thread to hold the bolt while I worked the epoxy putty in and around the broken casting area.Vantage 500's LN-25's, VI-400's, cobramatics, Miller migs, synch 350 LX, Powcon inverters, XMT's, 250 Ton Acurrpress 12' brake, 1/4" 10' Atlantic shear,Koikie plasma table W/ esab plasmas. marvel & hyd-mech saws, pirrana & metal muncher punches.
Reply:Originally Posted by abbascraigI've welded quite a bit of cast alum. just did the side casing on a sportster on the bike! Done outboard boat motors and props as well, and I've found that 4043 works fine. You do have to "V" it out as much as possible and clean with solvent and wire brush any oxide from weld zone. As far as the location of your particular situation, Good luck!
Reply:I geuss I should have asked at the begining about filler. I've welded quite a bit of cast aluminum from hogs to pump/gear housings. I'd prefer not to weld hog stuff, it seams the stuff is so precious no one wants to pay for something that cant be purchased any more. But I know Cadillac is also special thought maybe somebody has welded a newer Cad. block. Once again thanks for the info fellas.
Reply:Originally Posted by hotrodderThere's at least one thread in the pics and projects forum showing a similar repair, may be helpful. IIRC poster may have been Castweld?What that Alcotec filler selection doesn't show is the filler chemistry (there are more detailed pdfs for the various filler alloys on the site). 2319 has very little silicon, 4145 is a much closer match if the block is 319...Artificial aging 319.0 (from 'as cast') would be something along the lines of 8 hours at 205C for a T5 temper. Welding heat treated alloys typically results in a combination of annealed/partially annealed areas and over aged areas in the weld and HAZ. Annealed/partially annealed areas will make a partial recovery with time (varies with different alloys) which can be improved by artificial aging but aging has little effect on overaged areas. For something simple like a bolt hole lug my approach is usually to minimise the amount of overaging that occurs- a gentle preheat to keep the temperature gradient sensible and minimize the heat input.
Reply:I told him to bring it in.
Reply:I have a Cadilliac Sedan DeVille engine Northstar 32 Valve V8 with a crack block.  is there anyone in the Tampa bay area that does aluminium welding?  I have attached pictures.
Reply:Hi You may contact these guys they have been working with the northerstar engine for some time.  http://www.chrfab.com/.Years ago I had a problem at work with a busted bolt boss like that and a local welder used a mig gun to aluminum weld build up.  And we drilled and taped it with great results. have funTom
Reply:yeah on a deal like that as long as you have access your pretty much ready to go with mig or tig.......the hardest part will be drilling and tapping after the build up......I see that your damaged threaded area is close to a gasket surface......Be ready to get some air on that area when done welding it will take that gasket out if you don't, and might anyway so be aware of that deal....Last edited by B_C; 05-04-2011 at 12:27 PM.  Miller Dynasty 350Twenty Six HammersThree Crow BarsBig Rock
Reply:If your problem is similar to Arobina07's pics, I do a bunch of this for the local salvage yards. Get some carbon rod slightly under thread bore size in the bad hole. Tig with 4043 pushing the puddle against the carbon. Drill carbon rod out and tap. Most of the time tap will pick up orig thread and I don't have to use a thread insert.PeterEquipment:2  old paws2  eyes (that don't look so good)1  bad back
Reply:Cool good to know......where do you get the carbon rod?  Miller Dynasty 350Twenty Six HammersThree Crow BarsBig Rock
Reply:http://www.mcmaster.com/#graphite-rodsThe stuff at the top of the page is carbon fiber with expoy.  The stuff lower down I believe is solid carbon.  It says up to 800F in air, but 5000F in an inert atmosphere.  You may have to turn up the shielding gas and hold the torch over it a while for it to cool down so it doesn't catch on fire.Last edited by AndyA; 05-06-2011 at 02:09 PM.Dynasty200DX w/coolmate1MM210MM VintageESAB miniarc161ltsLincoln AC225Victor O/A, Smith AW1ACutmaster 81IR 2475N7.5FPRage3Jancy USA1019" SBAEAD-200LEI did the same type of repair on a hot rod Chebby motor with a broken starter ear..You may get some ideas from it..http://weldingweb.com/vbb/showthread.php...hlight=Starter...zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:Originally Posted by B_CCool good to know......where do you get the carbon rod?