Center section of manifold cracking..

[Rawze]

(01-18-2025 )marek4792 Wrote:  Bumping the post yet again. So it cracked the 2nd aftermarket manifold. Noticed white smoke on start up and when it first gets going and an occasional haze prior to and after overhaul. At this point we're strongly suspecting an injector is running afowl in a loaded condition, while passing a leak down test with 500 psi loss in a minute. EGTs 1075 at its highest since removing the radiator shrouds.

Cracking an exhaust manifold is not a common thing. Its usually due to improper install or some form of engine abuse (excessive hp/torque vs. the components). Are you pushing the engine past its factory HP/torque ratings?. What is the average engine loads looking like in the graph?.

are you sure your not over-tightening the manifold bolts and they are not allowing for heat expansion?. Are the expansion joints of the 3 sections seized up?. Has anyone surfaced the manifold as a whole to ensure it sits flat and there is not stress?.

1050F exhaust temps are not excessive (post turbo). Above 1100F+ would be.

Has I reviewed the programming to ensure its not abusive?.

also, aftermarket manifolds... I don't trust em, and there are no engine/efficiency/etc. gains for using them.