The dumps work. No more leaking circulating pumps. My oil temp at wot is lower. The Merc pumps move lots of volume. If there is not a good way for the water to get out the pressure will be high. Thanks for the test results.
Dan

I have talked with a few engine builders about water psi and it's effect on head gaskets. I spoke with Eickert and his feeling are that he does not like to see pressure above 25psi. I was asking for a friend.

My concerns were the oposite, because my motors run 8-10 psi at 4500 plus rpms. But when i thought about it water pressure is a mesurement of not how much water you are flowing, but how much restrictions you are putting to the water. I am moving plenty of water volume to keep my motors cool, have plenty of water dumping out my exhaust just not many restrictions.

Had to gut the stats to get them down to 15PSI @ WOT.