Operating Temp? Thermostat Kit Or Not?

[H20MOFO]

My Boat Likes It Hot, I Have Aluminum Heads, And Have Heard, That They Are Different Than Iron Heads. Timing Wise ,temp Wise,jetting,ect.(gotta Heat Em HOT To Make Some Power) Whatta Ya Think?

[Sleeper CP]

Not all that different. You can run about one point more compression without detonation.
Some people run their boats cold at 120 or so. I run the BB Ford at 140-150 on the temp gauge, because at that temp the oil gets to 180-190.
I really just use the water temp to control the oil temp through the heat exchanger/cooler. It can run for miles at 140 water temp and 190 oil temp at 3,800-4,000 rpm's. Then when we put a hard load on it racing back to back the oil will get to 210-220 degree's.
Sleeper CP
Big Inch Ford Lover

[GAWnCA]

So Sleeper, How do you control the temp? Thermostat or water flow? Do you have a gage at the engine?

[Sleeper CP]

So Sleeper, How do you control the temp? Thermostat or water flow? Do you have a gage at the engine?
Sorry about that: water flow.
I dislike electrical gauges so they are all AutoMeter liquid filled mechanicals.
Gauges are mounted in dash. Oil pres, oil temp and water temp.
Sleeper Cp
Big inch Ford Lover

[76miller]

Water flow. Use a water pressure regulater for the flow coming into your block, and a gate valve after it leaves the block. You can adjust the gate valve to fine tune your temp. With a thermostat you don't have any adjustment.

[H20MOFO]

Cp, Or Anyone. If You Control Temp With The Gate Valve ,have You Re-routed The Valve Where You Can Get At It Without Diving Under Your Headers?(back Of Boat)

[Sleeper CP]

We have just got use to the valve at the back of the boat. There is so
much crap in our bildge that we just left it comming off the pump.
I saw a picture on a thread somewhere on Just Jets where a guy put a
3/4" house pressure regulator in his system before it went to the engine.
Sleeper CP
Big Inch Ford Lover

[centerhill condor]

I run a prv year 'round. In the winter I install a thermostat. Summer no stat. Works very well and I have no high or low temp issues.
CC

[bp]

My Boat Likes It Hot, I Have Aluminum Heads, And Have Heard, That They Are Different Than Iron Heads. Timing Wise ,temp Wise,jetting,ect.(gotta Heat Em HOT To Make Some Power) Whatta Ya Think?
this topic has been hashed many times on here over the years. several of us use a zurn-wilkins 600lpv water pressure regulator off the pump. this regulator controls outlet pressure to a preset value, the range being 10-35psi. factory setting is 20psi out. the purpose of the regulator is to prevent overpressurization of the heat generator (engine), not to control temp. when running, jets can generate anywhere from 5lbs to 500, depending on how much power is applied - the 600lpv can regulate up to 350psi down to 110, which is plenty good for 1200 hp (approx).
water temp is not a direct measurement of engine temp in a single pass system open system, compared to a closed cooling system you would have in your car/truck. it is simply telling you water temp out.
the amount of heat being removed from the engine via the cooling water can be calculated by subtracting the Tin from the Tout, multiplying the result by the volume of water pumped through the engine (heat generator), in lbm/hr. the Tout-Tin is the temperature difference, or delta T.
given that the engine will remain consistent in the amount of heat generated at various loads, and at anything over 2000 rpm the pump is discharging over 10 psi, the only way to increase the delta t is to reduce flow through the engine. this will only result in less heat removal, and can dramatically affect performance in a negative way. i'll try it this way: the engine will create the same heat no matter what you do to try and get your water temp higher. failure to remove that via the cooling system can result in harm to your engine. you can run the Tout at 115-120 for years with no problem. if you think your heads are too cool, go back and put your hand on them after running for 15-20 minutes at this water temp, and see if they feel "too cool".
you'll notice a difference in delta T when lake/river temps change. in the middle of winter, Tout will drop way off because Tin might be 10-20 degrees cooler. again, the engine is still creating the same heat, but air temp will cool it off quicker than in the summer.
ask bruleracer about engine performance at various Touts. you'll find that engines (with alum heads) make more power at lower Touts.
jon mentioned he's running an oil cooler, which is not a bad idea when running a lot on the river in the summer - higher water temps, higher air temps make it harder to adequately remove engine heat generated. however, i dislike liquid filled gauges because the readings can change quite dramatically with barometric pressure.

[GAWnCA]

So, with all this said, what is your solution to both temp and pressure control?

[Sleeper CP]

Hey BP,
I have experienced a lot of what you wrote.
At the beginning of boating season when the water is cooler the water valve is closed down 1 - 1 1/4 turns more than in July-Sept(early) when the water is a few degree's warmer.
When my brother and I first got into boats 20 years ago I asked a lot of people about the water temp deal. I heard more off the wall answers and when I brought up the single pass/open water system I just got blank stares or "no the engine temp is the water temp". No it's not, not in a open loop system. That is when my brother and I decided to control the oil temp.
If the oil is hot, the engine is hot. If the oil is cold the engine is cold. Pretty simple. I still don't know if it's the best way to do it. I just know that I can control it and know what it is.
On the gauges: I don't like electronic sending units, that's all. And the 2 5/8 inch liquid filled guages look best.;)
As far as pressure goes: A 3/4" house regulator for $ 75.00 from HomeDepot will probably work or a $300. special marine one will do the job on the inlet side before the water enters the engine.
Sleeper CP
Big Inch Ford Lover

[bp]

i don't have any problems with elec gauges. in fact, just installed a whole new set, plus oil temp, in my brand new 30 year old 23' hallet supertanker jet. they work great, especially since i rewired the entire underdash.
oil lubricates and removes heat, so oil temp is critical. however, cylinder walls and heads aren't cooled by oil; heat is removed from those areas via water (and air). if you're keeping your water out temp at 140 or less at speed, you're probably ok with the oil cooler. but people that try to raise the water temp to 180 (because that's where there car temp is) stand a real good chance of having inadequate heat removal via those water passages and damaging the engine.
the thing about a regulator, zurn or the bypass duane sells, is that it must be able to provide 10-15psi out with fluctuating inlet pressures, which can get up there. wherever they come from, home depot, lowes etc., they have to function correctly all the time. i dismantle mine once a year and make sure everything is clean and spiffy.
i've seen pics of cooling systems with so many hoses running all over the place that you can't even see the engine, which is absurd and unnecessary. i've seen guys successfully run their cooling systems backwards (in at the top, out at the bottom of the block). i had one old friend (now deceased) that purchased a brand new 1974 witchcraft, 425 olds/jac. that engine's water temp never exceeded 120, running 500-600 lake hours per year for 25 years (he finally had it rebuilt in '99). the only problems he ever had were the occassional dead battery, and one time the voltage regulator went south.
for h20, keep it cool for best performance and longevity.