Ford block

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A customer came in with a block that has some cracks around the motor block and asked if I could braze it up.  One of my concerns is the amount of heat that I have to pour into the block may melt some (what looks like) lead (melting point of 621.43 °F).  Also, because it is such a large piece, will a regular electric stove get it to a temperature I can work with?And I found some additional cracking in between the water jackets. Attached ImagesCommon sense in an uncommon degree is what the world calls wisdom.
Reply:I'm one of the worst people for trying to salvage the unsalvagable, but....is it worth it or is the block irreplaceable. Looks like a lot of work that you're going ot have to charge for...Mike
Reply:That could be a 75 year old Ford "B" or maybe a Ford industrial block, a crack-free replacement would probably be tough to find.I think an electric oven would warm it up just fine. I don't know if you have to bake it way up to 600 degrees. You could give it some extra local heating with a torch, in the repair areas.Good Luck
Reply:Electric stove as pre-heat source?  IMHO, nopeElectric oven as pre-heat source?  Sure.And while PURE lead melts at 621.42F, various lead alloys can have melting points/ranges from 361.4F (lowest melting point for a tin/lead solder, specifically the 63/37 Sn/Pb eutectic solder,  used primarily for electronic/electrical soldering) to a high 579-689F solidus-liquidus for 94.5Pb-5.5Ag lead-silver solder.  Other 'lead' looking metals may have various melting points higher or lower than that.The found cracks that were circled/outlined were just from a visual inspection, or was a dye-penetrant or mag-particle inspection done?  If visual only, I'd suggest doing the 'goop' testing as well.  Suggestion:  preheat well and then let it cool s-l-o-w-l-y after the repair.  As in preheat then do the repair and then put it back into the oven and let it sit at the pre-heat temp and then drop the temp maybe 25F per hour or so.  Yes that means a day or two of cooling (in the oven).  If you have a programable time-vs-temp controller, all the better.  If not, a lot of manual thermostat babying (with some 'extended' equalization durations from about 8PM to 6AM or so, depending on how late you will be at the shop one day and how early you will get back there the next morning.    )  The best laid schemes ... Gang oft agley ...
Reply:Ever seen this system in use http://www.locknstitch.com/RepairExamples.htm ? Have a look at their examples good pics and explanation. It's unreal the repairs they've done in anything from turbines to engine blocks, the Wartsila generator is unreal...Mike
Reply:Oh, and the electric oven has to be able to get HOT enough.  500+ F at a minimum. Some 'home' ovens can (barely) get there.  Max temp of about 1200F, but if you are brazing you probably don't want or need to get that high.  The best laid schemes ... Gang oft agley ...
Reply:I'd stich it, the babbit will melt somewhere between 400 to 600 degrees. Even w/o preheat welding the water jacket bottom may transfer enough heat into main web to melt babbit. looks like an A?If needed you can get babbit re-poured but places that still do this are getting scarce. Check prices for re-pour before deciding what to do.A's are still common and may be cheaper to replace than repair.Peter