Water Pump Ports

This is how I see it.

With a bypass, the heat within the block is more evenly distributed at all times. Why is that not a good thing?

My theory and I'm sticking to it.

 

I wonder if the thermostat closed fully when the bypass was not used. The Heavy duty thermostat I went to had v - notches and slowly closed. Also might collapse the radiator hose without the bypass.

 

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Maybe the bypass is to prevent cavitating the pump?

 

Which is what gives me the scratching my head issue. Seems like the bypass should either be there or not be there on all engines, regardless of whether they have heater or not. So why do some have it and some not. I guess I could maybe see an argument that in really cold climates, the bypass would allow the head to warmup quicker. And no need for the bypass at normal areas as it will heat up quick enough. Since Willie was bought and spent his entire life in central Texas, he would not need the bypass. But when we move to Colorado I may want to consider adding it for winter driving.

 

If it was a cavitation issue, all engines would have the issue. And warm climates it would be more likely to attemp to collapse a warm hose, thus the spring?

 

I meant all F134’s would have them.

 

I just have a intuitive feeling it may be the opposite - the bypass circulation may prevent 'hotspots' within the block passages when extreme cold prevents the thermostat from ever opening at all.

I have experienced an F-head violently boiling over at -20ºF. I attribute that to thermostat housing being very exposed to the cold air. It was after I installed a 180º thermostat, and stopped when I went back to the 165º unit.

 

A wise friend once told me that any thread of more than ten posts is discussing a distinction without a difference.

Except he didn't put it quite so politely.

 

Saw a couple LHeads yesterday - 3A and 2A. One had the bypass fully hooked up and the other wasn’t even drilled/tapped on either the head or pump.

 

The circulation I was referring to as warming up the head would also be the same as your hotspot idea. Circulation would help both. Would be interesting to see if there was ever any documentation where the ones sold in say Colorado had them. My Texas one all its life does not have it.

 

Kinda like my Thermos bottle... keeps stuff hot in the winter and cold in the summer.

But how does it know?

 

The American ones have an intelligence to know, but the Chineese crap ones may or may not know or work or last long enough to get to the next season.