An friend and associate just purchased a used supercharger for his 15 year old Mustang, which he keeps in the garage and drives for special occasions. The super charger itself was in good shape, but when the previous owners engine failed something must have hit the drain plug boss on the bottom casting of the supercharger and cracked it. The first three pictures show the dent in the casting and some of the cracks that were present.



New castings are no longer available from Ford, so he asked me to weld it up. The first question is what Aluminum alloy was the casting made of. The casting was very smooth and there were what I believe might be ejector pin locators, which would indicate that it was die cast. Usually the ejector pins are 1/8 or 1/4 inch, but these were larger so I wasn't sure.
4. Ejector Pins ?

The most common alloy for die cast Aluminum is 380. To confirm the alloy my friend brought it to a metal scrap yard and had them shoot it with their X-ray gun. The concentration of the various elements matched the Aluminum 380 alloy, so I purchased one pound of 2319 welding wire, which is recommended for welding this alloy.
I decided to machine off the existing boss because the crack around it would be difficult to grind out and the threads in the boss were stripped as shown below anyway. What was left of the threads were also filled with RTV.
5. Stripped threads on drain plug boss
New castings are no longer available from Ford, so he asked me to weld it up. The first question is what Aluminum alloy was the casting made of. The casting was very smooth and there were what I believe might be ejector pin locators, which would indicate that it was die cast. Usually the ejector pins are 1/8 or 1/4 inch, but these were larger so I wasn't sure.
4. Ejector Pins ?
The most common alloy for die cast Aluminum is 380. To confirm the alloy my friend brought it to a metal scrap yard and had them shoot it with their X-ray gun. The concentration of the various elements matched the Aluminum 380 alloy, so I purchased one pound of 2319 welding wire, which is recommended for welding this alloy.
I decided to machine off the existing boss because the crack around it would be difficult to grind out and the threads in the boss were stripped as shown below anyway. What was left of the threads were also filled with RTV.
5. Stripped threads on drain plug boss
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