Super Jet FPP Chamber and Water Boxes - Cracking?

[Midlake Crisis]

A couple of years ago I chased my tail for months with a used FPP chamber I bought that cracked and re-cracked in a different place after I had the first cracks welded. Now I have a used FPP water box that seemed great when I got it and now has cracked just below the inlet. WTHeck? Is this common or just bad luck?

 

[badvinny]

They are light, so they are thin too. Any stress's or tensions from the manifold or hosing will give you trouble's like that. Its not a Pfp thing but an "aftermarket' thing, you have to fit stuff like that perfect yourself, its not OEM.
Although I do think the angles built into their waterbox fittings dont line up to their own pipe, OK, its a PFP thing!

 

[kevbo]

A couple of years ago I chased my tail for months with a used FPP chamber I bought that cracked and re-cracked in a different place after I had the first cracks welded. Now I have a used FPP water box that seemed great when I got it and now has cracked just below the inlet. WTHeck? Is this common or just bad luck?

Aluminum has very low fatigue life compared to steel. FPP used thin aluminum on SJ chambers because it hangs off the coupler. The side effect is cracking over time.