Non land mana sources that produce 3+ mana (one of which has to be white).
Steps
Cast Stonecloaker.
Paradox engine triggers untapping all our non-lands.
On resolution, Stonecloaker's ETB effects trigger, to preserve your own graveyard stack them as bounce, then exile, but to just exile all yards, order doesn't matter.
Tap all non-land mana sources for mana.
Responding to the exile trigger by casting Stonecloaker again allows you to repeat this process ad nauseum while only selecting a finite number of targets before letting the exile effects resolve.
Results
Infinite ETB.
Infinite untap all non-lands at instant speed.
Possibly infinite mana (requires nan land mana sources of 4+ mana).