Adding a thermostat and housing using pipe fittings

[vtmetro]

Nice job, WGB. Wish I had a TIG welder. I've often thought about building one. Cool if it could run off the roid.

[Tom]

Why not just use a 2 x 1" bell reducer instead of the pipe cap? Threads are already there.

[vtmetro]

Why not just use a 2 x 1" bell reducer instead of the pipe cap? Threads are already there.

Already mentioned twice.

FYI I had one in my hand at the hardware store but looking at it, decided against it. Heavy and big. Kinda clunky/ugly. Also I notice most old thermo housings are dome shaped. Also it makes the whole thing taller, which tends to sag the radiator hose. Finally, the more iron mass and cooling area around the thermostat the slower it gets hot enough, and the slower it reacts initially. I noticed this when scanning all the parts with the non-contact thermometer during warm-up. These roids put out not a lot of heat (by car thermostat standards) and you can really drop the temp fast with a big chunk of metal.

But of course it would probably work if it appeals. Variety is the spice of life.

EDIT:

We really want to lose as little heat as possible to and around a remote thermostat, as well as in any upward flow piping in a thermo siphoning system. In the best setups for home heating, hot runs are insulated, while cold returns are left uninsulated. This adds to the siphoning effect. We could actually insulate the thermostat housing and upflow hot pipe.

I think an in-head thermostat is probably the ideal (though a side mounted one probably should be air bubble vented near the top). But mine seems to work very well so far, so I'm happy. Again, many choices, many ways to do things.

[sailawayrb]

Here's how I did mine:

http://listerenginegallery.com/main.php?g2_itemId=351

see "CO2 Emergency Shutdown System 6".

I wanted the temp sensor between the head and the thermostat so shutdown would still occur for high head temp even if the thermostat failed closed.

Bob B.

[ronmar]

Here is how I have done some of mine:

Like many, I modified the thick cast outlet flange on the engine to hold a 195F auto thermostat.  You cannot even tell it is there by looking at it.  The only mod required to do this besides the small step on the inside edge of the flange, is to cut back a little bit of material in the head outlet to accept the thermostat bulb/spring end.  I also had to cut back the narrowest end of the close pipe nipple that is threaded into the flange.  An unaltered nipple will bottom out against the flange before the threads fully tighten.  This is probably mostly due to the slight difference between BSP and NPT...  I like this method as it puts the bulb/sensor end of the thermostat IN the head...



This next one is how I currently have my 120F thermostat on the outlet of my heat exchanger secondary loop.  The thermostat is under the brass pipe reducer, plugged into the male pipe outlet of the heatex.  This thermostat provides a pretty constant 120F water output, with the flow determined by the engine load.



Before I arrived at the final heatex configuration, and while I was initially testing the performance of the heatex, I had the thermostat plugged into a pipe, and a hose was slipped over the pipe and secured with a hose clamp.  In my case, the thermostat flange was a pretty tight fit with the hose ID, but if the fit was looser, a second hose clamp could be used to compress the hose just past the thermostat flange to keep the thermostat from shifting down the hose.  This worked very well for a low pressure application such as my test rig, and would work equally as well for a no pressure listeroid cooling application.

[12 gauge]

For welding cast iron, I've had pretty good results arc welding with nickel rod.  However, I didn't have any when I built my thermostat housing so I tried plain old 6011 rod.  The end result had a weep or two,  but after a couple weeks of use these disappeared.  I think the porous holes just fill up with iron oxide till they're watertight.  That housing is giving good service today.
RH

[vtmetro]

Just a follow-up. No problems so far with the original design using JBWeld..

[vtmetro]

And a further update. After a couple years, no leaks. JB Weld works fine for this application. Thermostat still working great, and auto-siphoning to an automotive radiator with no water pump.

[vtmetro]

And a further follow-up after 5 years, no leaks.

I will say that I've had good luck doing small cast iron welding since I first wrote this thread, using 7018 rod, short welds, and peening while it was cooling. But perfectly happy with the original JB Weld constructed thermostat housing, which I've never replaced.

[richardhula]

Not suggesting any problems likely with the OP'S setup but I had an over-cooling issue with my JP2, traced to the thermostat bleed hole someone had drilled measuring 8mm.

On my setup the original gear type raw water pump was being used to circulate coolant around a closed circuit system having skin tank cooling, so probably at some pressure. This was allowing coolant to pass through the thermostat well before it opened. Replacing with new thermostat drilled with 2mm bleed hole (max recommended) cured the issue.

[ronmar]

Especially in a pumped system, too much bypass and low load can be a problem.  I maintain a 100KW Generac that wouldn't get up to op temp at 20KW load.  Generac added a bypass line and a little manifold to connect additional temp sensors.  At that load in our cool PNW climate with it's massive radiator, the bypass provided all the coolant flow necessary and the thermostat never would open.  I made up blocking panels to glock off about 3/4 of the radiator to more closely match it's capacity to the generator's load. Now it runs properly at design thermostat temp when powering the site load. 

[vtmetro]

And a follow up after 14 years of use. The thermostat housing has never leaked. JB Weld was a adequate to the job by any measure.

Unfortunately it looks like all my photos are gone. and since this forum doesn't allow users to edit former posts, I can't add them back in. Unfortunate.

[keith71]

It is a shame that most of the old project pics that people put up years ago are no longer here...

Would it be possible to do a small replacement thread on your thermostat setup ? And just add the pics again?  A quick how to thread with a link from this thread. No explantion needed to write up again. Thanks..