(01-20-2020, 11:40 AM)rasmeidirt Wrote:

(01-20-2020, 01:54 AM)fixkick Wrote: one more. (there are 3 paths for air leaks) here is path 2. (1 is crack.) 3 is head to exh port gasket bad.
brand new out of the box,

see the header collector port there, huge round and a bad gasket there will do the same thing, suck in illegal oxygen. mine too cracked, so, I replaced it.

Regarding the welding of cast iron, I have got four comments or suggestions as follows.

1- Some people can weld cast iron. i don't recommend it.

2- Not if its done correctly. Cast Iron is weldable, but requires special arc rods and the item needs proper prep and pre-heating. Brazing will crack again, but if its prepped and pre heated and cooled correctly then hot welded it will take a while. Nickel based arc would be better. Cold weld method is below. Can do it hot, hot is preferable, weld at 350F straight from the oven, and wrap in a weld blanket or cover in hot sand to slow cooling and relieve stresses. Cronatron 211 cast iron rods are the best i've found. Heat casting to 350F minimum to bake off any impurities, let cool slowly (blanket method will do here). V-groove the joint 90 degrees, leaving a small root, 1/16" to 3/32", then grind the surface of the casting to clean up the porosity about 1/4" away from the joint. Use low heat, 60 - 80 amps for a 3/32 rod, and weld stringer beads, not more than 2 - 3 inches in length. Peen the weldment between passes, and let the casting cool between passes so you can touch it with your bare hand. The more peening during cooling, the better. Avoid weaving because it contracts the edges of the groove too much and causes cracking. I've used many different types of cast rods for repair, Ni Rod, Arctec supercast 80 and 90, Arctect cast 3, Certainium alloys, and another, Cronetron 211. Cronetron 211, as put, "the cast iron problem solver', is by far the best I've encountered in the past twelve years. Any of these electrodes will work, as long as they contain a sufficent amount of nickel. You want a rod that has a good elongation, so it doesn't allow cracking before you peen. Some electrodes are designed for hot cast welding, where temps are controlled for lengths of time, and some are more forgiving. After the joint is filled, you can grind the face reinforcement off and finish the weld repair with a needle scaler to give it a 'as cast look' which also relieves stress at the same time.

3- Yes, cast iron can be welded and there is lots of information online. Most of what you read will be about static pieces that were broken. This is a piece that cracked from a bad design with stresses in the part itself. If you have it welded, check the gasket surface for flatness, before you reinstall. Welding can cause the piece to warp slightly. The longest surface is for the gasket. Welding on the runners can cause stress in different places, causing it to warp as it cools. Welding the part after it has been heated, will help.

4- If I were welding this, I would use TIG, as it will weld with low heat and not change the stress.

What do you think which one is the best to try?

(01-20-2020, 02:18 PM)rasmeidirt Wrote:

(01-20-2020, 11:40 AM)rasmeidirt Wrote:

(01-20-2020, 01:54 AM)fixkick Wrote: one more. (there are 3 paths for air leaks) here is path 2. (1 is crack.) 3 is head to exh port gasket bad.
brand new out of the box,

see the header collector port there, huge round and a bad gasket there will do the same thing, suck in illegal oxygen. mine too cracked, so, I replaced it.

Regarding the welding of cast iron, I have got four comments or suggestions as follows.

1- Some people can weld cast iron. i don't recommend it.

2- Not if its done correctly. Cast Iron is weldable, but requires special arc rods and the item needs proper prep and pre-heating. Brazing will crack again, but if its prepped and pre heated and cooled correctly then hot welded it will take a while. Nickel based arc would be better. Cold weld method is below. Can do it hot, hot is preferable, weld at 350F straight from the oven, and wrap in a weld blanket or cover in hot sand to slow cooling and relieve stresses. Cronatron 211 cast iron rods are the best i've found. Heat casting to 350F minimum to bake off any impurities, let cool slowly (blanket method will do here). V-groove the joint 90 degrees, leaving a small root, 1/16" to 3/32", then grind the surface of the casting to clean up the porosity about 1/4" away from the joint. Use low heat, 60 - 80 amps for a 3/32 rod, and weld stringer beads, not more than 2 - 3 inches in length. Peen the weldment between passes, and let the casting cool between passes so you can touch it with your bare hand. The more peening during cooling, the better. Avoid weaving because it contracts the edges of the groove too much and causes cracking. I've used many different types of cast rods for repair, Ni Rod, Arctec supercast 80 and 90, Arctect cast 3, Certainium alloys, and another, Cronetron 211. Cronetron 211, as put, "the cast iron problem solver', is by far the best I've encountered in the past twelve years. Any of these electrodes will work, as long as they contain a sufficent amount of nickel. You want a rod that has a good elongation, so it doesn't allow cracking before you peen. Some electrodes are designed for hot cast welding, where temps are controlled for lengths of time, and some are more forgiving. After the joint is filled, you can grind the face reinforcement off and finish the weld repair with a needle scaler to give it a 'as cast look' which also relieves stress at the same time.

3- Yes, cast iron can be welded and there is lots of information online. Most of what you read will be about static pieces that were broken. This is a piece that cracked from a bad design with stresses in the part itself. If you have it welded, check the gasket surface for flatness, before you reinstall. Welding can cause the piece to warp slightly. The longest surface is for the gasket. Welding on the runners can cause stress in different places, causing it to warp as it cools. Welding the part after it has been heated, will help.

4- If I were welding this, I would use TIG, as it will weld with low heat and not change the stress.

What do you think which one is the best to try?

FSM short and Long Terms https://imgur.com/gdYL13Q

Output from ECM https://imgur.com/4NcMAsa Output from ECM https://imgur.com/ZV7ajWa