Small Block & Big Block Chevy Specific - engine redline

alright guys, when building a engine how do u find or determine the engines max redline. that way i can know what to set the limiters or tach limiter at and know what speed not to spin it at. is there a formula or something?

Your engines redline is a combination of the springs stiffness and the cam's power curve. If you cam peaks at 6500RPM and your springs are stiff enough to run it up the high then you can set your limiter/light at say 6600RPM. If the cam peaks but still carries power for several hundred RPMs then you can shift as high as you feel comfortable

Your bottom end also plays a role in maximum rpm, different pistons (hyper, forged) have different maximum speed ratings.

so would it be safe to say after the peak happens give a hundred or some rpms then limit it?

The bottom end is one of the main limiting factors.

so how do engine builders or auto companies decide what is the redline of a engine?

so how do engine builders or auto companies decide what is the redline of a engine?

Cam specs. No sense running an engine to 7k when it runs out of breath at 6k. The bottom end and valvetrain are then built to handle the cam's powerband.