How much antifreeze is "a lot"- - - - -a quart, a gallon, or a few ounces? Was the oil milky-looking? Some 216's have a hard time maintaining any oil pressure at all at idle, particularly if they've been assembled with main bearing clearances a little on the wide side. Since the rod bearings aren't pressure-lubricated, they can be a little loose without dropping oil pressure. Not so with main and cam bearings! How much oil pressure did the engine have when cold and the pump being run by a drill motor?
Jerry
