Z482 coolant flow

[dieseldude]

Good evening,

I have been refreshing a z482 engine and recently managed to get it running well, although it has been short runs. Today is the first time I have run it for an extended time and all looks good, but I have a question about how much coolant should it be pumping. Since this is a custom project and I do not have a radiator attached, I'm using a modified bucket gravity feeding into the bottom connection and have the upper hose returning back. Water temp stays between 160-180, but the flow rate to me seems like a trickle. Would this be normal, or should I have better flow?

Thanks.

 

[motorhead]

Is the engine a thermo siphon or does it have a water pump and thermostat?

 

[dieseldude]

water pump and thermostat.

 

[Stumpy]

It sounds fairly normal. They way forced water systems are usually setup there will be minimal coolant flow through the radiator unless there's a load on the engine. When the thermostat is closed it redirects the coolant flow back into the block where it just circulates. When the coolant temp reaches the low end of it's opening range it just cracks to allow some of the flow through the radiator. As the coolant gets hotter more and more flow is sent to the radiator. When ever it opens with your bucket setup it gets a big gulp of comparatively cold coolant and slams shut again. You'd see more flow with a load on the engine and after the bucket has had time to come closer to the coolant temp.

 

[motorhead]

It sounds fairly normal. They way forced water systems are usually setup there will be minimal coolant flow through the radiator unless there's a load on the engine. When the thermostat is closed it redirects the coolant flow back into the block where it just circulates. When the coolant temp reaches the low end of it's opening range it just cracks to allow some of the flow through the radiator. As the coolant gets hotter more and more flow is sent to the radiator. When ever it opens with your bucket setup it gets a big gulp of comparatively cold coolant and slams shut again. You'd see more flow with a load on the engine and after the bucket has had time to come closer to the coolant temp.

Stumpy said it the same I would. The thermostat regulates the engine temperature by how far it opens. Well said Stumpy!

 

[dieseldude]

That explains it. I had been working on the assumption that it's either fully open or fully closed. I hadn't considered partial opening. Running with very light load isin't working hard enough to call for more flow. Thanks for the insight. Much apperciated.