Ive been looking at few different crate engines, and one of the things ive been having the hardest time doing, is deciding if nodular iron is strong enough to handle more power. From wat i know, cast is weakest, nodular is in the middle, and forged is at the top. How much power will the nodular iron cranshaft handle? The engine im leaning on makes 355 hp and 405 tq with 10:1 compression. Also its says it is a Nodular iron H/P crankshaft. What does the h/p stand for? Any help would be great. thanks

mitch

 

Ive seen cast cranks handle more power than that, so a NI crank should be fine.

 

"Strength" is a relative term, and can be defined in several ways. Each material has its advantages and disadvantages.

Nodular iron is more ductile than cast gray iron, so it will be a bit less brittle. It can tolerate more harmonics and shock loading. Yield strength is about the same or actually a bit lower than gray iron. For a crankshaft, nodular iron will survive high loading better since the major loads are impulsive.