Running FZ6 w/ No Rad and/or Coolant

[DefyInertia]

You may very well be right... I Googled it and seems that the consensus is split on the subject... Some say yes the water pump needs coolant to be lubed, but it can survive periods on just water. Others say, no coolant is not needed if only to be used as a water pump lubricant.

And still others say...

Waterpumps dont need coolant. They have sealed bearings that are permanently lubricated.

bike by bike issue perhaps?

 

[xj750_Pete]

if you are going to run it without coolant to hear the exhaust, at least hook up all the hoses. That way the pump doesnt suck in unfiltered air. I'm not sure what kind of tolerances are used in water pumps, but I don't think tiny particles of sand and dust are good for it. I do agree with others that running the engine without coolant is safe as long as it is for only a short period of time and with little load. I remember when i was little my uncle was changing out his coolant in his truck. He pretty much opened the drain, started the engine and let the coolant run out for awhile and then he stuck a garden hose down the radiator. After about a minute or so he shut off the engine drained the water, refilled with antifreeze/water and away he went.

 

[wolfc70]

Can you or someone else expand on this???? I thought being partially filled would be a plus.

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I mean that there is air in the system. If there is air, the water pump can cavitate and cause the coolant to foam, thus decreasing the coolants ability to transfer heat. You would have some latent heat cooling for a while as the coolant changed state, but not for very long.(Water loses 970 BTU's per pound changing to steam). The bearing does not need coolant to run, but the seal needs some form of lubricant (water, coolant) to survive, just as any moving seal does. The short time you are going to run the engine, will not build up enough heat to damage the seal.

I would reconnect the hoses as when you start it, the coolant in the block will most likely exit the system when it is started.

 

[CHEMIKER]

So what did you end up doing DI? Did you start it? Did you and your bike live to tell the tale?

 

[flyer34]

Most likely you wouldn't do any damage just running it for a few seconds with no coolant, however I would NOT recommend it. Best case is nothing bad happens, worst case is you ruin your cylinder heads.

The hottest part of the engine is in the cylinder heads around the exhaust valve/port. There's no way to guess how fast these areas will heat up and how hot they will get with no coolant circulating around them. It's conceivable that they could heat up very quickly and crack.

Also, the fuel injection system probably incorporates a coolant temp sensor. If it does, the bike might not run right, or the computer might throw a code if run with no coolant. It's also conceivable that the sensor could burn out, depending on how it's designed.

The coolant pump itself is probably the least of your concerns. Most water pumps are a simple design with a single impeller pushing water through at relatively low pressures compared to something like an oil pump which usually have gears or two metal parts moving together to generate much higher pressures and friction.

 

[DefyInertia]

I ran it for 15 seconds or so with a few blips and then apologized to my bike for doing so.

Pipes sound great. I didn't lose any additional coolant and was able to hold my hands on the headers after a few seconds of cooling (all four were evenly warm).

Thanks for all the input...such a silly thread

 

[CHEMIKER]

I ran it for 15 seconds or so with a few blips and then apologized to my bike for doing so.

Pipes sound great. I didn't lose any additional coolant and was able to hold my hands on the headers after a few seconds of cooling (all four were evenly warm).

Thanks for all the input...such a silly thread

Glad to hear that it went well.

Happy also to hear that your pipes rock!

 

[HavBlue]

The waterpump on the FZ6 is mechanically driven as opposed to belt driven like a cage. The T-Stat begins to open at 160 degrees f. Running the engine for a brief period without coolant or water shouldn't hurt a thing which is also true in the case of a cage. We used to run the 468 Chevy in the boat I drove for roughly 2-3 minutes on the ramp before dropping it in the water. This allowed the engine to heat up to operating temperature in a much shorter period of time. If you put it in the water first it took much longer to actually hit the mark. Never had a single problem with the pump and we never had a drop of coolant, only cold river/lake water.

In the case of the FZ6 I don't see an issue providing the run time is brief.