Motorgen - Automotive Events, Meets, Cruises and Forums - View Single Post - Time For The Cobra To Get A New Engine

SkunkLookingCar · 10-12-2012, 05:49 PM

Little late replying but I might be a bit hesitant reusing the pistons with nicks in them. Worst case scenario, if they are made of a high silicon alloy like hypereutetic castings or a 4032 forging, then they are brittle and you probably already have cracks in the pistons which will propagate over time. Best case scenario would be if they are a 2618 forging; it is a much tougher material and the nicks would only act as a stress riser. Blending out the damage would help but now you don't have a compressive layer from the shot peening process. It is tough throwing out parts that are 99% perfect but it is really just a coin toss without doing some sort of non destructive testing like sonic and penetrant inspection. By the time you get that done, you are probably better off dollar wise getting new slugs. My 2 cents.

10-12-2012, 05:49 PM	#17
SkunkLookingCar Member Join Date: Nov 2010 Posts: 92 Tweet	Little late replying but I might be a bit hesitant reusing the pistons with nicks in them. Worst case scenario, if they are made of a high silicon alloy like hypereutetic castings or a 4032 forging, then they are brittle and you probably already have cracks in the pistons which will propagate over time. Best case scenario would be if they are a 2618 forging; it is a much tougher material and the nicks would only act as a stress riser. Blending out the damage would help but now you don't have a compressive layer from the shot peening process. It is tough throwing out parts that are 99% perfect but it is really just a coin toss without doing some sort of non destructive testing like sonic and penetrant inspection. By the time you get that done, you are probably better off dollar wise getting new slugs. My 2 cents. __________________ Easily entertained.