"I am going through my 40a's and they consume motor oil without the usual signs. They run fine, no smoke, etc. The oil pressure is low. After 10 minutes of running, it needs a quart or two. I am in the process of getting the head ground and resealing the oil cooler. There is no oil in the fresh water, but there is a small amount of water in the oil. Any suggestions on what to look for next?"