When do you replace the factory valvesprings?

[Morse]

I've heard of people running very low 11's and still running factory valvesprings. When is it actually a requirement? I have a single 74 and much larger injectors on their way to me, and plan on pushing the 06 pretty hard. It's currently trapping in the high 112 mph range with just a PS62 and 90hp DDP injectors. When does the factory valvetrain need to be upgraded to prevent damage?

 

[jelag]

The factory valve springs are well designed... . I currently do not know a manufacturer of a spring that's better than the factory one... . On the 12V engines we'd change them to the HD spring used by Cummins in some of their industrial engines to support the exhaust brakes... .

Unless your intent is to exceed the current RPM limits of this engine I can't see why you'd want to make this change... .

 

[JHardwick]

Unless your intent is to exceed the current RPM limits of this engine I can't see why you'd want to make this change... .

Agreed, RPM is the spring killer.

 

[WUnderwood]

I'd go with some F1 valvesprings, so you dont float the valves.

cheap insurance, I think

 

[Vaughn MacKenzie]

helix 24v springs