SoCal Jet Boats
Tech Talk => Engine Mechanical / Electrical => Topic started by: havasudre on May 21, 2007, 06:37:41 PM
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my boat runs super cold my friend said i need to put a thermostat in it
like a car / should i even worry about this problem ?
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my boat runs super cold my friend said i need to put a thermostat in it
like a car / should i even worry about this problem ?
Adjust the valve going from your pump to your engine so that there is less water going into your engine.
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I'm not that knowledgeable on boat engines but should it even matter as long as you're getting a good idle?
Better that it runs cool rather than hot as long as it idles as desired; maybe I'm wrong.
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I'm not that knowledgeable on boat engines but should it even matter as long as you're getting a good idle?
Better that it runs cool rather than hot as long as it idles as desired; maybe I'm wrong.
You'll find about ? 5 ? really good ways to keep your jet boat cool and not too cold or too hot. There is an excellant post in here somewhere, I think it was called how do you keep your boat cool?, I think? When the jet boats were built that we're generally talking about in here they did not come with thermostats. The temperature was regulated by how much water was allowed to through through the engine which was controlled by the valve coming out of the pump. Car engines in cars use thermostats. Marine engines in boats and car engines in boats have much higher cylinder temperatures than car engines in cars. With that in mind you want the water temp gauge to show a lower temp in a boat than you do in a car. Also, somewhere I read that the Berkeley pump puts out like 200-250 pounds of water peressure. If you install a thermostat you are blocking that pressure with that thermostat unless you devise, or follow, a way to get rid of that extreme pressure. A cars water pressure is what? Like 15 pounds?? Anyway I'm sure you get it. You can't install a thermostat in a jet boat and do nothing else, your engine is sure to blow up either by water pressure or by cylinder temperature.
Try to find that post and print it out and read it. ;)
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The thread was called How I keep it cool!
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The thread was called How I keep it cool!
We know you keep it cool Marc....Ya' proved that at El Capitan! ;D
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You can run a pressure relief at 15-20# and dump the excess overboard... This should keep the same volume of water going to your block with moderated pressure, possibly allowing the block to heat up a bit more. From there you can run a t-stat if you need more heat. I think "optimal" engine temp is ~180. My jet won't see 120 if the gate is left wide open -if I close it, it would be reducing volume, not pressure and steaming up in there. I'm a newb, so I'm sure others can chime in on this subject and explain it much better.
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the motor is a fresh rebuilt
can i go the weekend with out it ? it idles just fine
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If you've got a thermostat in there with no means to relieve the water pressure - then I doubt if it would last the weekend, But I'm not an expert by ANY means.
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Heres how mine is done . I have a gate valve at the pump and at an idle the motor wont go over 180 which I think is kind of high but not terminal so I really dont care . When I jump on the gas it goes down to about 140 -150 and my theory is that the water pressure is turned down (I dont know how much because I dont have a gage) enough by the valve to not let the motor over heat but at speed cool the engine enough to still make enough heat for good performance . Another plus is that with the pressure turned down , the pump wont blow out any gaskets . Now tell me how many times do you here of people complaining about how they got milkshake in there motor and it turns out its a blown gasket.
-beerjet-
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Heres how mine is done . I have a gate valve at the pump and at an idle the motor wont go over 180 which I think is kind of high but not terminal so I really dont care . When I jump on the gas it goes down to about 140 -150 and my theory is that the water pressure is turned down (I dont know how much because I dont have a gage) enough by the valve to not let the motor over heat but at speed cool the engine enough to still make enough heat for good performance . Another plus is that with the pressure turned down , the pump wont blow out any gaskets . Now tell me how many times do you here of people complaining about how they got milkshake in there motor and it turns out its a blown gasket.
-beerjet-
I think that's what I recomended at first as well. Turn the valve down so there ain't as uch water going in thereby relieving the pressure. ;D That's how they built them when they were new. ;)
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You don't want to run a normal automotive thermostat in a boat engine because even a cool thermostat is going to be 155-160 degrees and even with running the water through the exhaust manifolds first it may only reach 140-150 degrees. What you can do is get an assortment of water flow restrictors from Moroso (variety of discs with different size holes in them to regulate flow). The engine will run better if you can get your water temperature above 150-160. Good Luck.
Keith
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I think that's what I recomended at first as well. Turn the valve down so there ain't as uch water going in thereby relieving the pressure. ;D That's how they built them when they were new. ;)
If you control off the gate isn't there the same pressure, just reduced volume? If you have 50# in 1/2", you would still have the same 50# but going through 1/4" (or whatever size) so same pressure but lower volume. You would run cooler at higher rpm vs. idle because the increased pressure will move more volume through the block until the pressure is maxed, then you get mikshake. I'm going to run a pressure relief for safe keeping and also hoping to get more heat to the block...
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If you control off the gate...
... That's how they built them when they were new. ;)
My G/F's uncle has a early to mid 70's Kona that he bought new that still has the never touched 427 Chevy in it. I dunno, maybe it's just because it's a CHEVY!?! >:D ;D
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If you control off the gate isn't there the same pressure, just reduced volume? If you have 50# in 1/2", you would still have the same 50# but going through 1/4" (or whatever size) so same pressure but lower volume. You would run cooler at higher rpm vs. idle because the increased pressure will move more volume through the block until the pressure is maxed, then you get mikshake. I'm going to run a pressure relief for safe keeping and also hoping to get more heat to the block...
I dont think so . If you go out to the water spigot in your yard and open it , volume will increase as well as pressure and thats with a constant pressure feeding the valve . Besides he could also try running the water through his snails also before feeding the motor (if it isnt already like this )or reducing the size of the line feeding the motor . I'm just goin on my personal experience and without lookin at it or some real detailed pictures with hose routing I'm just "stabbin in the dark ."
-beerjet-