Welding freeze-cracked engine block

[Vtnewbie]

GM V8 engine block cracked down above/along bottom skirt due to water in the block last winter. Prior to welding, do I need to drill the ends of the cracks (as for stress cracks) to stop the cracks propagating? I'm concerned about the amount of heat I'd be introducing to fill full-depth holes, rather than just covering the v'd out cracks.....

 

[Shield Arc]

Ever do this before?

 

[ak9]

Quick answer is yes ....... But b4 you put any electric to it ...there is the prep.....pre heat to 500 F ish slowly then the electric weld with high nickel rod then the slow cool down to 200 F ....best to mag flux or other means to determine the Very end of the cracks tho . I've found to enlist a pair of "other" hands to hold the pre-heat torch and the no contact themo to be most helpful in doing this type of repair

 

[Vtnewbie]

Thank you sir!

 

[stuckmotor]

Ak9,
How far from the sides and ends of the crack should the pre heat extend? I'm just curious.

 

[flusher]

GM V8 engine block cracked down above/along bottom skirt due to water in the block last winter. Prior to welding, do I need to drill the ends of the cracks (as for stress cracks) to stop the cracks propagating? I'm concerned about the amount of heat I'd be introducing to fill full-depth holes, rather than just covering the v'd out cracks.....

I recommend this rod:

Super Missileweld | The Harris Products Group

I've used 1/8" rod to a weld broken flange back onto the engine block of my Farmall Cub using my Hobart Stickmate LX welder. Works fine. Just follow the manufacturer's recommendations for polarity and amps for the rod size you select.

I didn't use preheat. Just made 1" long stringer welds. Measured the temperature with an inexpensive IR thermometer from Harbor Freight. Kept the temperature below 400F and let the block cool down to 100F or so between stringers. Peened the welds with a pointed air chisel during the cooldown to relieve stresses.

Good luck.

 

[Shield Arc]

We used Super Missile Weld for quite some time, trying to keep cast steel pile driving equipment together. Then we switched to 312 stainless steel.

 

[arkydog]

look under repairing dodge cummins diesel 5.9. engine block #57 cast on block side. there is a company the makes a insert that you drill along the crack and use their tool and insert and side by side you repair the cracked block. its a fix for the block that cracks because it was made too thin.

 

[yomax4]

Super Missile Weld Is 312 Stainless. I prefer Spray Powder on any cast under 1/2" thick. ( Nickel Iron powder ) Never Fails. On the thicker material I recommend short 1" stich welds. One at one end and one at the other after drilling the ends, Let it cool while peening the bead to relieve stress and repeat the steps again. Buy premium rod like MG 289. Just my opinion. I used to sell maintenance and repair alloys and have burned a lot of nickel and spray powder. There are some very good Nickel Free synthetic Nickel rods out there too. Good luck..

 

[pmsmechanic]

I've had good results using ArcTeck 223 welding rods for cast. I've never welded a block though. I'll learn something here.