Thermostat probe

I have a hemi in My 67 coronet and have an aftermarket temp gauge that is connected into the water pump housing next to the heater core in/outlets. I want to go to an electric fan setup and keep the aftermarket setup as is but need a suggestion on where to install the electric fan temp probe. I see Chevy has a thermostat housing for small blocks that has a port for a probe. Is there one available for BB mopars ? It was suggested to install the probe in the rad fins. (not real enthused about that) My radiator is aluminum aftermarket Champion. Thanks in advance to all. Thanks Moparts

Here you go. efi t-stat adp.

Thank you for posting that. My plugs in the housing are so corroded that it would require a torch by all the perfect stuff in my engine bay. Should be able to slip this in and use an aftermarket gauge. I don’t trust the factory one all that much.

That is way to cool !!!! Thank You very much

I'm looking on line and there is a housing with a port to accept the probe and it says compatable for BB mopars and smallblock chevy. Anyone see something like this?

Shouldn't be to hard to find, The mancini piece is nice but bend me over rover LOL .

Speedway, jeg's Summit, circle track, Ebay AND Amz.

the chevy housing has the same bolt spacing, but is a slightly different shape, and may or may not fit the thermostat [correctly].
i fiddled some with a spacer used on a chevy dirt track car, and while it fit on a big block water pump housing, it was a shape that looked odd on there, [at least to me] and required the bottom of the spacer to be machined to accept the big block thermostat. the chevy thermostat will fall through the big block housing, as it's the small size similar to the later small block and magnum size thermostats.

It’s only $15 more than the Meziere I use, and I would have gladly paid that for the better positioning of the sensor

Flex a lite makes a fan controller with a probe you put in the rad hose by the radiator. You also can adjust what temp you want the fan to come on at.
link

I looked at them, the do not make an in the hose probe.

They make two types, in the fins and a thread in sensor set up.

I am using the adaptor that Mancini sells on my 440 based 511. AndyF makes it. It is a high quality piece. I'm using it to provide a place for a zinc anode to protect the aluminum heads, water pump housing, and radiator. It doesn't stand out, looks wise.
I have got to the point that I realize that parts that are made for our old mopars are going to be expensive, so if I think I need it, I bite the bullet and buy it and don't look back.

Well they used to because i have one. The kit comes with a piece of tapered rubber you put on the probe so the clamp doesn't crush it(inside the hose at the upper rad inlet). They may not make it anymore but you should be able to adapt one to work. Here is one but not flex a lite.
link

I never liked that shove the probe into the hose method. Crude and rude to me.

I would worry about the probe / wires eventually failing as well as leakage. One could easily use a TEE in the heater hose supply side. Another option that may be possible is to drill another port ahead of the factory temp sender depending on the size of probe and available material

Terzmo the poster of this thread has a Hemi engine and needs to oil his wallet so it does not squeak when he pulls the 45 Washingtons out. The spacer is a neat way to get it done. My Mancini housing had extra ports. The factory housing or his housing might be able to be drilled and tapped.

Probably a reason they don't make it any more.

Yea mine was a pain to get is sealed but after you do it's good. Getting the temp from engine is not ideal because the thermostat will be closed until it reaches the opening temp then it circulates the coolant threw the radiator. If the temp(on the controller) is lower than the opening of the t stat it will turn on the fans when the coolant is not being circulated(threw the radiator). Getting the reading from the circulated coolant is more accurate. Putting the sensor in the cooling fins should work but getting the temp direct from the coolant would be better. If i where to do this again i would opt for a controller that uses a thermistor sensor rather than a mechanical thermostat. This one just happened to come with the fan.

You'd be much better off putting your temperature sensor where the coolant enters the block. That way you are using the OUPUT of the radiator to control the fan. That is how it is on my 1 Plymouth when I converted it over.

It is also how the OEM's have done it for years. Which to clarify, is on the engine side of the T'stat not the radiator side. This will give you the most accurate reading of the engine temp.
Putting it anywhere else can be misleading/ disastrous if the thermostat malfunctions as you would then be reading the radiator coolant temp not the engine temp.
Spal sells 2 preset sensors that I have had very good luck with. They can be used with normal 5 pin relay (available anywhere).
they control the fans by grounding the relay coil. I have new ones still in the packaging, If anyone is interested PM me

TS-185 it turns on at 185 and of at 165, I have One
TS-195 it turns on at 195 and off at 175, I have 2 or 3
Pretty sure I even have a few or their wiring kits. if anyone is interested PM me

i agree the temperature sender or probe needs to be after the radiator, and preferably in the water jacket around the cylinders.
a good place [in my opinion] would be where the block drain plug is located.
i am also a guy that likes to see the engine temperature at, or around, 195-215 or so. this is with a 16lb or higher [20-22lb dirt track radiator cap] radiator cap, and a 35-50% mix of water and coolant.
i think the extra heat produces a tick more oomph from the engine, as well as making sure all acids and moisture's are boiled out of the block internals.
remember, this is just my [old man] opinion.
your mileage will vary.

I have always tried to get the sensor as close to the T/sat as possible for the aforementioned reasons and run pre mixed coolant or distilled water mix. if one doesn't have to be concerned with freezing, minimal coolant drastically improves the cooling. One of the Laser systems I was involved with functioned 100% with straight DI water. BUT Marketing insisted on being able to ship the systems loaded and over-nite if needed. Enter Glycol, and 9 month's of added work finding a gas mixture that would work. The performance took a real hit but met their requested criteria

This is a good thread with valuable discussion.

I am late in reading it.

My take away:
in the future when giving advice
urge the original poster to use two thermometers to measure at the inlet and outlet of the radiator,
either by inserting a thin probe inside to touch coolant at the hose slip on joint,
or by touching two aluminum or brass radiator fins.

There have been hundreds of cooling discussions on Moparts
and this basic point about getting good engineering data has been seldom mentioned.

It is even more true in freon HVAC system where before and after temperatures and pressures are “industry norms.”

It is related to the joke:

Dentistry costs money,
lack of good Dentistry costs even more money.

(because the bacteria P. gingavalis that attacks the gums also attacks the lining of blood vessels throughout the body, heart valves, and maybe the brain itself)

You are correct in gathering the data and analyzing it to devise a path to a solution. Due to my background in this area the in vs out difference tells you how much heat is being removed and the efficiency of the radiator. But if one does not know what the efficiency should be or is not able to calculate it leaves them with another unknown. The other variable(s) that enter in are the efficiency of the core itself, how clean it is, it's physical condition, air flow, speed, fans etc.
External probes will give you an indication, The same is true for IR heat guns.
I have always used a Thermocouple probe placed directly into the coolant as close to the thermostat (OUTLET side) as possible. The T/C probe is then plugged into a laboratory grade digital meter which can be placed in the car through a window if needed (usually is).
The probe is very sensitive and quick responding. so much so that if a semi should change into your lane you can watch the meter climb until a good distance is established at which time it will start dropping back.
Another interesting tidbit, with marginal cooling system, Going N on I-29 from the I-680 interchange the temps will climb. How fast depends on the cooling system (radiator usually)
Going S on the same road they drop or stabilize. This section of road appears to be level but obviously is not. The same variables can be duplicated on other highway's that do have noticeable grades.
One thing I learned from Glen Ray is that all cores are not created equal, even though the catalog may say they are a direct replacement, that is not always the case for the older cars. This is due to the bean counters using thinner tubes, fins and cheaper manufacturing methods.
There are also different cores to choose from, economy, mid, high. Then throw in the number of fins, tubes, whether the fins are louvered of not as well as a potful of other variables like staggering the tubes and the Manufacturing processes used.
Generally speaking, if the T/sat or restrictor is in place, pully ratios are correct, belts are tight and you have a heating issue at highway speeds. It is most likely the core or misdirected airflow.
If the problem is at low speed / idle you're not getting enough air across the core. Do keep in mind a less efficient core will require more air.
Another final tidbit, removing the hood will generally drop your temps ~ 15-20 degrees