Camshaft mixing: Largeport & Smallport

[dr.occa]

I haven't done this myself but was just studying camshaft profiles from the Miata 1.6 (90-93) and postulated that there maybe be some gains to be had by using a largeport exhaust cam (7.56mm lift 240° duration) in a smallport engine while retaining the smallport intake cam (7.1mm lift 232° duration); both camshafts would be using the factory cam gears with no adjustment.

If I had another 86 to try this out in it would be done "yesterday" but unfortunately I don't.

If anything, this might even be the direction to go when going boost.

[AznTKDmstr]

i have big port cams in my smallport - i've read somewhere that you get slight power gains doing that... but i have no idea what a stock smallport feels like to compare the two