bubbles in the rad

[Soundguy]

Ummm...what?



QUOTE]

I saw that too

 

[wrenchturner]

Running an engine without pressure in the radiator could cause air to be sucked into the cooling system and definately will cause cavitation which will lead to no blades on the coolant pump and possibly eroding away the coolant pump housing. How do you think a squirrell cage fan functions? Centifugal force causes a low pressure in the center.

The simplest way to check for a leaking head or gasket is to remove the coolant pump belt, remove the upper radiator hose or thermostat housing , run the enigne and look for bubbles.

 

[Soundguy]

wow.. I need more posts like that. my farm is in dire need of fertalizer.

non pressure cooling systems were used on some tractors back in the day.

for either, as long as the inlet is submerged .. no air is going down.. remember rad top / top hose is OUTLET.. and N tanks are DESIGNED to have a large air space at the top.

mm.. got to remember taller boots..

soudnguy

 

[Short Game]

The suction side of the pump could create some vacuum bubbles. This would mean a lower pressure on the suction side of the pump. That pressure gradient is what the pump is supposed to create. The future of any vacuum bubble in water is to collapse as water falls into the evacuated space. Water on the pressure side of the pump vanes cannot be compressed, and it will push ahead, moving the water in front of it.

If a normally pressurized cooling system is full, the change in pressure by removing the pressure cap will only change the boiling point of the water. Some systems are designed to run above 212 degrees F. for better engine operation. In such a system, the water can boil out without a working pressure cap. If the radiator is working properly, and the engine is working properly, one should have plenty of time to look for bubbles before the water reaches 212. At any rate, cavitation bubbles can not exist on the pressure side of the pump.

I suppose there could be a case where a gasket could only leak when the water temp is above 212. In such a case, looking for bubbles in the radiator would not tell you anything useful.

 

[Egon]

Them cavitation bubbles might be hard to see at anytime.

 

[Short Game]

I learned about cavitation in a submarine. The main noise a propeller makes comes from cavitation, or vacuum bubbles, created when the leading edge of the screw moves water at a speed and power such that the viscosity of the water prevents the water from moving as fast as the edge of the screw, creating a temporary cavity. The noise of this cavitation comes from the clapping shut of the water as the fluid pressure overcomes the space the low pressure bubble had briefly occupied.

 

[jonyyuma]

I used to have cavitation problems with my boat motors. Stainless props and proper trim seemed to help it.

 

[Soundguy]

luckilly this ain't a sub.

I'm quite aware of what cavitation is and does. that made us go thru that in engineering school.

it simply isn't a bone picking issue in this application.

and IF someone thought it was.. an sca/dca addative can be added, or simply purchase a fleet pre-charged diesel antifreeze.

end of story.

soundguy