I have a crusader 270 which is currently burning about 3 quarts of oil over a 5 to 6 hour cruise at about 2900 RPM's. Both heads and head gaskets were replaced over the past three and four years. The boat sat idle all season last year due to replacing the other engine. This seems to have happened this year. Prior years, the oil consumption was normal. There is no blue smoke coming out of exhaust, but a slight sheen of apparent oil. No sheen from other engine. The engine starts well and seems to run strong. Had done an oil change at beginning of the season and had limited use until recently. No misses or hesitations. There is no evidence of oil leaking beneath the engine. Durning the head gasket and head replacements, there was antifreeze in a few of the cylinders which was cleaned out prior to new head gaskets and heads. This engine does not seem to have an oil cooler, only a transmission oil cooler. Manifolds risers and elbows about four years old but again, no use last year. I am baffled, any input would be greatly appreciated!