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-   -   Theory ... water flow (https://www.offshoreonly.com/forums/general-q/148666-theory-water-flow.html)

PatriYacht 01-19-2007 09:37 AM

Re: Theory ... water flow
 
I am also running steam hoses on my intake. It is common enough that most hi perf intake makers cast bosses in the proper place so you can drill and tap them.

the duke 01-19-2007 11:51 AM

Re: Theory ... water flow
 

Originally Posted by Stingray69 (Post 1997850)
The deal with using NO thermostat is you will run too cold. It acts to restrict the QUANTITY of water, so that the block CAN warm to 140-ish. but IF you run with no T-stat and NO circ pump, the pressure in the block WILL be more than the gaskets can take. Instant milkshake following a WOT run, or dyno pull. Watched two buds do this for themselves; I don't need to go there, myself, to see I don't want to. This is where the Merc pressure relief valve dumping overboard, comes in.

running with cold water is not a big deal, IF your oil temp is where it should be, which is above 212*. As far as the pressure into the block no thermostat and no circ pump has very little to do with it. There are a ton of restrictions there already, starting with the thermostat housing. Its a function of several things, the main one being how fast you are running the boat. At X speed, you are pushing X amount of water into the pickup. At that speed, the amount of water being pushed into the pickup doesn't change if you do or don't have a stat/circ pump. Your gauge should show just about zero water pressure when you are not moving, and it increases to a certain point as your speed increases. In most cases, water dumps are not needed until you get into very very high performance/high speed boats. I've run in boats at near 100 with no dumps,no circ pump, and they are only making in the low 20's water pressure. An OL running 150 with twin blower motors is a totally different story.

99% of what applies to cooling in a car does not apply to a boat. Cars are not running at anywhere near the load that boats are. Plus they have computers and emmissions that need the high temps to run correctly. I run 130 water/230 oil in any temp lake water from 50* to 75*. I do run a restrictor in place of the stat, BUT that is because without it my oil temp was not running above 180, which caused condensation. It runs right about 20 psi at WOT of 5600 RPM.

what water/oil temps are you running, and what water pressure? and at what speed

monstaaa 01-20-2007 10:05 AM

Re: Theory ... water flow
 

Originally Posted by PatriYacht (Post 1998257)
I am also running steam hoses on my intake. It is common enough that most hi perf intake makers cast bosses in the proper place so you can drill and tap them.

exactly.

monstaaa 01-20-2007 10:07 AM

Re: Theory ... water flow
 

Originally Posted by the duke (Post 1998410)
running with cold water is not a big deal, IF your oil temp is where it should be, which is above 212*. As far as the pressure into the block no thermostat and no circ pump has very little to do with it. There are a ton of restrictions there already, starting with the thermostat housing. Its a function of several things, the main one being how fast you are running the boat. At X speed, you are pushing X amount of water into the pickup. At that speed, the amount of water being pushed into the pickup doesn't change if you do or don't have a stat/circ pump. Your gauge should show just about zero water pressure when you are not moving, and it increases to a certain point as your speed increases. In most cases, water dumps are not needed until you get into very very high performance/high speed boats. I've run in boats at near 100 with no dumps,no circ pump, and they are only making in the low 20's water pressure. An OL running 150 with twin blower motors is a totally different story.

99% of what applies to cooling in a car does not apply to a boat. Cars are not running at anywhere near the load that boats are. Plus they have computers and emmissions that need the high temps to run correctly. I run 130 water/230 oil in any temp lake water from 50* to 75*. I do run a restrictor in place of the stat, BUT that is because without it my oil temp was not running above 180, which caused condensation. It runs right about 20 psi at WOT of 5600 RPM.

what water/oil temps are you running, and what water pressure? and at what speed


some times oversizing the oil cooler for the application causes the issue of lack of temp , as far as low oli temps.


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