Custom cam or regrind on your standard cam

[thexav]

Which would be better a custom new perfromance cam or a performance regrind on your standard cam?

Are they the same thing or does the regrind come with a downside?

 

[old-git]

Regrinding existing cams is fine for low stages of tune. For serious tuning trying to fit the desired profile within the existing profile requires compromises.

For example, on single cam engines, the LSA (Lobe Separation Angle or the number of degrees between the intake and exhaust lobe centerlines) cannot realistically be altered.

Hopefully, this image explains why billet cams are better:

 

[TCJBOLDIE]

My understanding is when the cam is reground the BCD is reduced to keep/increase the lift.

 

[PDDesign]

Fresh grind is pretty much always better as you can have both duration and lift. Lift is more important from the point of view of torque at lower rpm. Regrinds attempt to increase lift through reducing the base circle diameter, but my experience is that this is limited.

If you want a motorcycle type response and you've got the bottom end that will stand it, then a regrind concentrating on duration is fine.

However, for a road car a billet grind is better

 

[TCJBOLDIE]

When billet cams are no longer made for your motor them the lobes can be welded to build them higher so they can be reground for more lift/duration without having to reduce the BCD at all.