A V-type vehicle engine includes a main engine body with a front bank and a rear bank defining a V-type structure. A plurality of valve actuation units are respectively located in valve chambers in the front bank and the rear bank, to minimize the size of a cylinder head and a cylinder head cover in at least one of the front bank and the rear bank. A first valve actuation unit, with a double overhead camshaft structure having intake-side and exhaust-side camshafts individually corresponding to the intake valve and the exhaust valve, is located in a valve chamber in one of the front bank and the rear bank. A second valve actuation unit, having a common single camshaft for the intake valve and the exhaust valve, is located in a valve chamber in the other one of the front bank and the rear bank.