What Temp Is Your Jet Boat Motor Running?
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Mine idles at 150 and wot it runs 105-110
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hand
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I use to shut my gate valve down to try to keep things 140-150 until I discovered to get there I was about 1.5 turns from all the way shut.)eek) Now that I've opened it all the way up and added a bypass my temp gauge doesn't move off the lowest. To my suprise it made no real noticeable difference in my oil temp.
)eek) Now that I've opened it all the way up and added a bypass my temp gauge doesn't move off the lowest. To my suprise it made no real noticeable difference in my oil temp.
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I would think that your engine should run at least 180, however due to the jet boat configurations and cool continuous water flow most do not reach that. As everyone has said, it falls far short of that. while technically you should be able to make more hp at lower engine temps, cooler temps are not good for the wear factor.
I run a thermostat and a pressure bypass to my wet logs. whenever the thermostat is closed the pressure bypass valve allows water to go around the engine and directly to the wet logs. when the engine reaches running temp, the thermostat opens dropping the pressure and the pressure valve closes. it has worked very well thus far running at around 190. however i do have an open mounted engine, meaning my engine compartment is not enclosed. I would be wary and watchfull of compartment temps if this is done on a boat with enclosed engine.
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160 at idle last night when I put my foot under the dumps and burnt it to hell
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You will want your temp to be different depending on whether you had the motor built to run in a jet or not.
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There are articles all over the internet about it...but yes you can in fact overcool an engine. A cold engine will also need a richer fuel/air mixture to run properly...waste of fuel IMO.Someone correct me if I'm wrong.....but isn't water temp irrelavent, I thought oil temp was the one that mattered.
Here's a really good article that talks about water plumbing and jet boat engine cooling systems. Talks about temperature spikes and how they're not good for a performance engine.
http://www.performancejet.com/ttjetboatenginecooling.html
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My performance engine runs 110* all day long. Most of the time im lucky to get it to 110* where i boat.
Ran it 110* on the dyno to. Seems to be working for me. I would like to get a bit more temp in it at times, but i pay attention to the oil temp more then the engine temp. You cant really get a good temp ready from the temp sender on the manifold because the water is moving to fast and it's not a closed system.
Ran it 110* on the dyno to. Seems to be working for me. I would like to get a bit more temp in it at times, but i pay attention to the oil temp more then the engine temp. You cant really get a good temp ready from the temp sender on the manifold because the water is moving to fast and it's not a closed system.
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Idling, 155 degrees, cruising or WFO, 125 degrees.
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That's basically what t-stats and restrictor plates do...slows the water flow through the block WAY down (almost down to a trickle) and keeps it in there longer so it has time to absorb heat from the block and heads. But there has to be some sort of a bypass for it to do it correctly.
If you look at the physical diagram of a raw water t-stat controlled cooling system, it's exactly the same as a closed cooling system...you just have a radiator with too much water for the engine to heat very much of it.
If you look at the physical diagram of a raw water t-stat controlled cooling system, it's exactly the same as a closed cooling system...you just have a radiator with too much water for the engine to heat very much of it.
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Well Skippy, that wont work for my engine. It was designed to run where it's running. To much bs with the T stat BS IMO. Mine works just fine the way it is. The engine gets torn down and inspected every year, so....If it aint broke, don't fix it.
And yes, I am running an inlet regulator set @ 22 psi.
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Jon I guess my point is ...if my oil temp is 190-200 and my water temp says 110, what one do you think is a better indicator of what the engine temp REALLY is??? One of the first things I learned back on HB is that water temp in a jet boat means pretty much nothing. Maybe the school of thought has changed since then,but I doubt it. The only thing I KNOW FOR SURE is that on my set up changing the water temp from 150-160 to not moving the needle made ZERO difference in rpm's, or my af reading on my wide band. One of the times we talked on the phone I asked you if you had a set up to monitor oil temp. Seems like you were working on it, what's your oil temp? If you pull you thermostat and run it "cold on the water gauge" you'll see it doesn't have hardly any effect. At least it didn't on mine. Different strokes for different folks I guess. Mofo out.....
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If your running at 110* and your oil temp is 190-220, i would pay more attention to the oil temp. I try to get my oil temp up before I call it a day to burn out the moisture. I also run a vacuum pump, and I seem to pull more water out of it then oil.
All in all, It sounds like your running fine right where your at.
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