Cracked 5.7 block at Starter Bolts

[man-a-fre]

Believe it or not you can mig weld it, I have mig welded a few I would tap the crack closed with a hammer grind a small v in the crack and stitch mig it like welding on a panel. I always make sure there is a brace on my Chevy starters seen this too many times.

 

[mattyg]

Believe it or not you can mig weld it, I have mig welded a few I would tap the crack closed with a hammer grind a small v in the crack and stitch mig it like welding on a panel. I always make sure there is a brace on my Chevy starters seen this too many times.

Did you use any preheat or post heat? I’ve welded cast but normally I’ll preheat to 400-600f, then cool slowly.

 

[drewcrew]

Getting a head start on pulling the engine, the cordless impacts and ratchet makes these jobs really enjoyable.

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If you would like more enjoyment stop by my house. No need to pull the engine just a couple small jobs. I'll supply the coffee. Thanks

 

[drewcrew]

Did you use any preheat or post heat? I’ve welded cast but normally I’ll preheat to 400-600f, then cool slowly. Did you use nyrod ? Spelling is probably wrong ? I think it has a high nickel content.

 

[Schurkey]

If that were mine, I'd fix it in-place.

Weld/braze the crack, drill for a 3/8-16 helicoil if required. The worst thing about a repair like this is that the hole in the block is sized to be a snug fit on the knurl of the starter bolt, and when you drill for the heli-coil, you're going to lose the snug fit, which means you lose the precision alignment of starter to flywheel. You'd get that back by drilling, tapping, screwing in the helicoil, then boring the lower part of the hole oversize again, and poke in a short sleeve to tighten the fit on the knurl.

 

[Frank Enstein]

If all else fails, THIS https://www.summitracing.com/parts/dck-10100 and

THIS https://www.summitracing.com/parts/pwm-3635/make/chevrolet/model/bel-air/year/1957

will take care of it!

 

[mattyg]

If you would like more enjoyment stop by my house. No need to pull the engine just a couple small jobs. I'll supply the coffee. Thanks

Sure if you cover the flight.

 

[kennythewelder]

There are a few different ways to repair that. All of them need to be drilled at the ends of the crack. If you braze then no preheat is needed. If you fill weld, then it needs to be V groved first, then preheated, to as mentioned 400° to 600° F, and slow cooled. A post heat after welding will help in this. If I was doing it, I would drill the ends with about a 3/16 drill bit or a 3/16 bur bit. Then V grove the crack, and TIG weld it with some N-99 rods, or just braze it after drilling holes, and call it a day. Depending on how the repair comes out, I mite add a all steel strap over the weld, and weld that for extra straight. And then, why did this happen to begin with. How is the fly wheel ? Is this a high compression engine ? Does it have a high torque starter on it ?

 

[mattyg]

There are a few different ways to repair that. All of them need to be drilled at the ends of the crack. If you braze then no preheat is needed. If you fill weld, then it needs to be V groved first, then preheated, to as mentioned 400° to 600° F, and slow cooled. A post heat after welding will help in this. If I was doing it, I would drill the ends with about a 3/16 drill bit or a 3/16 bur bit. Then V grove the crack, and TIG weld it with some N-99 rods, or just braze it after drilling holes, and call it a day. Depending on how the repair comes out, I mite add a all steel strap over the weld, and weld that for extra straight. And then, why did this happen to begin with. How is the fly wheel ? Is this a high compression engine ? Does it have a high torque starter on it ?

Flywheel is chewed up in spots, stock 5.7, starter is OEM direct drive. I am going to MIG weld it with pre and post heat. The entire ear is broken off, I will grind a Vee and pulse. I will post my results, tomorrow or Sunday. I am putting in a new flex plate so the motor is coming out. Good times.

 

[man-a-fre]

Did you use any preheat or post heat? I’ve welded cast but normally I’ll preheat to 400-600f, then cool slowly.

short bursts with mig no preheat several small tacks. I suppose you could preheat but I never had to.