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Cooling Question??

Smuggler

Smuggler

Well-known member
If 2 radiators measure out the exact same size BUT 1 had 2 rows and the other had 3 rows for coolant to pass threw which one would be the better radiator? Or does it matter?
Thanks!

:?:
 
The more surface area available, the better the radiator does at dissipating a given amount of heat. It has more to do with the heat load of your engine. Exp. A small four cylinder engine may not generate enough heat to justify a three core radiator. A single or double core radiator may be sufficient to transfer the heat load to the air in that situation. However, if you have a big block engine, you have a much larger quantity of heat you are trying to dissipate. You could cool a large engine with a single core radiator if it was five feet by five feet. It is all about surface area and the amount of heat you are dealing with. Hope that helps.
 
ON ANOTHER NOTE ! AIR FLOW IS A CONSIDERATION ON A AIRBOAT ! A THREE ROW WONT COOL MUCH BETTER THAN A TWO IN THE REAL WORLD! SIMPLE THING S SEEM SO SIMPLE ! THICKER IS NOT ALWAYS BETTER !
 
Seems most of the aluminum Rad's are 2 row from what I see, 1/2" deep.. Then you throw in double pass like Waterthunder recommends!

I would like to know if the loss of push from rad in front of prop would be better/worse than HP loss of running like a clutch fan and shroud in front of the engine (conventional auto) and the resultant HP loss? I bet it would work up here?? :?
 
So then WHY are people concerned about drag caused by expanded steel, 2"X2", 2"x4" to 4"X4" wire on the cages and drag and decreased push? :?
 
That's all I'm trying to bring out in this discussion, Less drag, more push right? I want something that will still stop stuff from going into the prop but least drag . That brings up this 2'X3' obstruction at the bottom of the prop, (radiator,cont520 I know you dont have that problem). Logic leads me to believe you would have to trim the engine up less at the back of the boat to reduce riding on the nose and the end result would be more thrust? Am I nutz??? :? Do they hang radiators immediately behind the propeller of an airplane in airstream or would that be too much drag. I agree we are talking higher speeds. The money we spend on little improvements of HP or propeller technology maby their are some inexpensive changes we can make to improve efficiencies?If a double pass aluminum rad, (Pretty little on Waterthunders boat and I'm sure he never runs less than 500 HP) works in your temps and the electric fan trick has not really worked, Horizontal rads with electrics and ducting, etc. What about stuffing it in front of the engine with a conventional clutch fan? :lol: :lol:
 
COLD":1vk44kbv said:
I would like to know if the loss of push from rad in front of prop would be better/worse than HP loss of running like a clutch fan and shroud in front of the engine (conventional auto) and the resultant HP loss? I bet it would work up here?? :?
Click to expand...

I've wondered the same thing about the radiator restricting airflow directly in front of the prop. Not just the drag that it creates but the turbulence also. The smother the airflow across the prop, the more thrust and efficiency the system should have. The larger the wire spacing on the cage, the less disturbed air hitting the prop and less drag in front of the prop. I don't recommend it but I've always wondered if there would be a noticeable difference in performance on a boat with and without wire on the cage. I did notice on Thunder's old boat that his radiator was mounted further forward than most yet apparently cooled just fine.

Since the engine is already blocking the airflow near the center of the prop, it seems to make sense to locate the radiator in front of the engine. Perhaps the additional heat from an airboat engine cannot be handled with a traditional clutch or electric fan and it needs the all the airflow that the prop can provide.
 
Well I have always been told that a prop can only grab so much air then cavitation occurs . I dont know the physics behind the matter or how much it can grab thats just what I have been told is it right dont know . I run my oil cooler in front of my prop just behind and above my gas tank
 
THIS WILL BE A LONG THREAD ! MOVE YOUR RAD UP 6 IN GAIN 100 RPMS ! NO WIRE 200 RPMS ! REMOVE YOUR DRY BOX UNDER THE SEAT 300 RPMS ! YALL GOT TO REMEMBER LAST 10 INCHES OF YOUR PROP REALLY DONT BLOW NOTHING ! WATER THUNDERS BOAT ,THERE IS NOTHING IN THE WAY HIS PUSH NUMBERS ARE WAY UP THERE !HIS RAD IS 2 FT IN FRONT OF HIS PROP ! THATS WHY AIRCRAFT BOYS GET MORE PUSH THAN US CAR MOTORS GUYS ! WE PUT EVERTHING IN THE WAY OF THE PROP !I HAVE SEEN THE TESTING DONE ! EVERTHING MAKES A DIFFERENCE ! THESE SUPERWIDES NEED LOT OF AIR TO PUSH IF YOU CANT SUCK IT, CANT BLOW IT !JUST FACT !
 
The reason I asked is. The one I took off the boat was a 3 row and the one I bought (without checking first) is a 2 row but they both have the exact same core dimensions. I am running the new ZZ383 on a 14' Alumitec hull. Should I take this 2 row back and get a 3 row? Or do you all think it will be fine. Remember the 2 row is still in the box and it hasn't been installed so I can still take it back. However if I put it on and it doesn't do the job, there is no taking it back. What would you do?

On another note.. It is interesting about the airflow issues. Why did everyone drop them and move them to the back? Is it because you can make the rigging shorter for shorter hulls? Very interesting talk!!!

Thanks for all the input!!
 
Hey Fatboy,

How does removing restrictions in front of the prop increase rpms? I'm not doubting the results of your testing, I just don't understand the mechanics of the results. I would think that the more air available at a given rpm would produce more thrust but how does that produce more rpm? Isn't rpm limited by the friction of the blade moving through the air? Less air = less friction it would seem that less friction would produce more rpm? A prop spinning in a vacuum would have no friction, thus what would the rpm be then? Would it go up or would the rpms go down? Again, I go back to the issue of turbulence vs smooth airflow. Perhaps disturbed air is harder for the prop to push through.

By moving the radiator forward as on Thunder's boat, it still produces the same amount of "friction" or "drag" to airflow, but air exiting the rear of the radiator has some time to smooth out before entering the prop.
 
Mudbug":jjbho5ft said:
Hey Fatboy,

How does removing restrictions in front of the prop increase rpms? I'm not doubting the results of your testing, I just don't understand the mechanics of the results. I would think that the more air available at a given rpm would produce more thrust but how does that produce more rpm? Isn't rpm limited by the friction of the blade moving through the air? Less air = less friction it would seem that less friction would produce more rpm? A prop spinning in a vacuum would have no friction, thus what would the rpm be then? Would it go up or would the rpms go down? Again, I go back to the issue of turbulence vs smooth airflow. Perhaps disturbed air is harder for the prop to push through.

By moving the radiator forward as on Thunder's boat, it still produces the same amount of "friction" or "drag" to airflow, but air exiting the rear of the radiator has some time to smooth out before entering the prop.
Click to expand...

This I know. On a trailer, more restriction (less airflow) is going to mean more rpms. Stick your hand over the nozzle of a vacuum cleaner and it speeds up because it's not doing any work.

This I think, but could be completely wrong. In the water and running, better airflow will let the boat run faster and as it runs faster, the angle of attack of the prop gets better and may allow more rpm.
 
WE ONLY TESTED SUPER WIDE PROPS AND THE FACTS WAS FOR MY SET UP !I UNDERSTAND WHAT YALL ARE SAYING ! WHICH IS TRUE TO A POINT ! BUT YALL WILL HAVE TOO REMEMBER OUR PROP SPEED WAS 1600 MAX ! WE WERE PULLING AIR FROM AROUND A FOOT AWAY FROM THE RIGGING EACH SIDE ! PEOPLE SAY WE PULL AIR FROM THE OUTSIDE ! WE DONT !ITS ALL IN A SMALL AREA THREW THE RIGGING ! AT LEASE ON MINE ! THE MORE AIR THAT IS NOT DISTURD OR HEATED OR ROLLED WILL LESSEN THE PULL ON A SUPERWIDE ! REALLY CANT COMMENT ON OTHER BLADES !ALWAYS HAD WIDE BLADES AND A 2.3 WHIRLWIND !THESE BLADES DONT CAVITATE LIKE SMALLER ONES ! THEY PULL A MORE LOT OF AIR THAN MOST BLADES ! PS A TWO CORE WORKS FINE FOR MY 506 CAD THEY NEED COOLING MORE THAN A SMALL BLOCK ! :D GATOR ! ONLY REASON THEY ARE WHERE THEY ARE IS FOR FROGGING AND IDLEING ! IF WE HAUL BUTT ALL THE TIME WE COULD PUT THE RAD UP FRONT ! :D
 
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