closed cooling

[Moody Blu']

is it worth it to get a closed cooling system?
my boat keeps almost over heating after wot run in less than a minute the temp starts to go up, once I slow down it cools down, WHAT GIVES?????
iVE BEEN THINKING ABOUT BUYING A CLOSED COOLING SYSTEM OVER THE WINTER, is it worth it?
my dad says I still have to run a pump for the heat exchanger?
can someone point me in the right way?
I am going out to eat I will be back soon.
grizzly help me!!!!
you to forrest!!!

[BigGrizzly]

There is no question the closed system is the way to go, especially in salt water. All my boats have them. Just designed one for my supercharged 502 with 698 HP. I came from the Point Pleasent NJ area and our 1966 16 has hade one since 1968. They stabalise the engine temp, My Corsican actually gets better fuel economy. and runs stronger longer. I keep the engine temp at 190 deg, and the echaust at 150-160. Sen-Dur made the exchanger and surge tank. I used auto stuff for the rest-its just like your car

Randy

[Moody Blu']

hey griz, or someone could you clue me in to what consist of a closed cooling sytem and if I could make one cheaer than the kits? what about air? dont you need some air to blow on the radiator?
I have no lcue how these closed systems work, I know what cars work like. but could someone explain this to me like I have no clue? cause I really dont.

[MOP]

What you are experiancing is what old boat mechanics call false over heat, when you chop the throttle after a hard run the hot water in the block rises as does the gauge it lasts maybe 2-3 minutes then cools to normal temp. Take a minute to read the rest!
Hi words from an old fart marine mechanic, I am now in my 60's I worked as a wrench for over 30 years and was a forman of one of the largest small boat yards on Long Island (SALT WATER). If I had TEN over heats a month NINE were fresh water cooled. Fresh water cooling does have its merits but is way over blown you will wear or blow them up before you rot them through. You are stealing horse power with the added pump and weight. Look under the cowl of the factory racers NO fresh cooling water there. These boys do the same as thousands of others FLUSH when done, I have 1/4 turn cocks on my block I dump the salt out put the rabbit ears on let the water run till it comes out the exhaust then start it and run it for 15 minutes. If you guys want to do something really good for your pony pusher add an oil cooler, use an over sized one necked down to fit your intake hose not to ad any flow resriction. Salt is bad but the brain can be much smarter use your head it is not that bad prepping and running in salt and you will without doubt be faster without fresh water cooling.

Phil / Long Island

[Moody Blu']

Thanks phil but, my problem is not exactly that.
if I go wide open for like 30 seconds or more, the temp starts rising. If I kept going it would overheat, and kill my waranty,(there are heat tabs on the block some where,if they melt bye bye waranty)
I am using a jabsco water pump run directly off of the crank(holman and moody design)

Hey one thing is that I am not using a thermostat.
the engine runs at 120 all day except for wot
I tried using a thermostat and my pump started to leak and so did my strainer, so I took the thermostat out.
I guess you could say I have a low pressure cooling system.
I know you guys are gonna say that the engine is operating inefficiently but I feel it has more power. maybe not.
please scold me now....

[BigGrizzly]

The closed colling system is just like the system in a car the heat exchanger replaces the rad. As for the mis conception that closed cooling systems do not increase horse power is bull. I run my motors at 195deg with the exhaust watte jacket at 140 to 160. the extra heat in the engine is more effience than an engine on the dyno I have the numbers to prove it. My Corsican with a 351 Clevland puts out 22 more HP at 190 than 160 deg, which makes it 425 hp. My Criterion with a supercharged 502 makes 42 more Hp at 185 than at 145deg to bring it up to 685.5 hp. Every boat I have had since 1966 has bennifited from a closed colling system, this includes my dad's 40 foot Qwens cruiser. I don't experience this hot chop problem with a closed system. and I am an old fart machanic of 55 years old. You do have maintain the system with antifrezze just like a car.
Racers eliminate the coolers for weight reasons. They do suffer through a multitude of other problems because of the way they are cooled. But than what do I know my boat only runs low to mid 80's.

[Moody Blu']

mad poodle, you may be right.the 750cfm that I have WAS leaned out a bit.

big griz is there any way I can tell if my engine is running to lean?
I know for a fact that the carb was leaned out from the previous owner, he told me he had a 383 stroker and it would bog down so he leaned it out, but the carb was just to big, but he had a car, a boat is a bit different.

big griz, or some body, could you please tell me what a closed cooling system consists of,
a radiator?
what else?
do I need airflow, or do fans on the radiator suffice?
how do you run the headers at a different temp?
are you running two different pumps? one for closed cooling and one for the headers?
pretty please could you tell me what a complete closed cooling system consist of.
maybe I could go to a junk yard and make my own.

p.s.,
if you have two different pumps,(one for the headers and one for the engine) and you run the engines at 195 degrees, doesnt the second pump ROB the horsepower that you are making?

thanks in adavnce for answering the questions I have presented :)

[Formula Jr]

Thanks Big Griz for the confirmation on 195 degrees. I always felt thats the way they should run, but no one ever tested it like you have. I have a 302 with - if you can suspend disbelief, 300K on it. The rest of the van is falling apart, but the engine still gives me 147 PSI all around on a compression test. You Have to get the oil up to temp to let it flow and stablize the engine block temp, the oil is the first of the two cooling systems, so I know what Phil is talking about with the oil coolers. But I also don't have three people on salary to take care of a race boat.

Insane French Dog.......Way-cool, on the plugs!
:)

[Moody Blu']

for anyone who is willing to figure out if my carb is to lean here are the specs.

its an edelbrock 750
#407 primary& secondary jets
#6847 metering rods
and silver metering rod springs
i hope someone can get spmethin out of that

[BigGrizzly]

Hey Sky, There is a heat exchanger, takes place of the Rad. Most engines have two pumps except when using a crossover that replaces the circulating pump-as on a car. Anyway I just stick a heat exchanger in where the Rad hoses should be and the raw water pump does the cooling of the heat exchanger, it is really that simple. Up untill recently no one has tried to do this to a full blown racing engine. My heat exchanger is on loan and is being tested on a 1,100 supercharged big block. So far its working ok and keeping the temps stable.nThis is a real plus for supercharging. This is all I can tell you about the project at this time.