Old B7100 - adding a temp idiot light

[85Hokie]

220+ F is a bit high - nothing too serious but high.

My question is what are the readings at the top and bottom of the radiator? This tells a much better story of how this engine is cooled.

If the the top neck is about 220 - what is the bottom neck reading? IF the coolant is not dropping a 100 F from top to bottom, there is a problem.

How many hours on the machine?

Last time you really flushed radiator?

How clean is the radiator? - this is the #1 problem, period - even when you think it is clean...... there is still crap stuck deep inside.

The gauge you installed - I wonder how accurate it is - despite those that do NOT seem to trust a infrared thermometer - they are extremely accurate if used correctly and can be bought for under 20 bucks.

For the cost - get two of these!

the uses are endless!

 

[slyoteboy]

I couldnt say on the bottom without a IR gun.

It has new coolant, drained it when I changed both the rad hoses. 1900~ hours. It has the pre screen which isnt dirty.

Good point about that gauge, it was a cheapy hard to say how accurate it truly is. Was just curious anyone else whos does this mod on a b7100HST what their temps are reading.

I will report back when I get that gun and take some reads.

 

[85Hokie]

I couldnt say on the bottom without a IR gun.

It has new coolant, drained it when I changed both the rad hoses. 1900~ hours. It has the pre screen which isnt dirty.

Good point about that gauge, it was a cheapy hard to say how accurate it truly is. Was just curious anyone else whos does this mod on a b7100HST what their temps are reading.

I will report back when I get that gun and take some reads.

This is top of neck and bottom of neck

 

[lugbolt]

I quit relying on IR guns.

IR reads surface temp. Often the coolant inside is considerably hotter. It takes a while for the surfaces that the coolant is running through to equalize temp with the coolant that is passing through. With cast iron and especially stainless, a LONG while.

They've fooled me many many times. Had an issue with the race car a while back and hit each of the header tubes with the IR. They all showed around 560 deg F. But EGT bungs showed 1140 on 7 cylinders, and #6 was around 780. #6 was NOT firing at all. Just blowing hot air and fuel out of it that had passed through the cylinder. if I had let it sit and run a while the temps on #6 would remain lower than the other 7, BUT it takes a hot minute to do so. Stainless headers with coating on them. The whole time, drinking fuel-probably take a half gallon of fuel or more to get to that point.

I've also had them fool me in many occasions in diagnosing overheating issues. M9540, thermostat housing reads 145 degrees on both sides. Ok it's stuck open. Took it out, no it wasn't. Really wasn't anything wrong but the sender was not functioning properly as verified by hot water, a thermometer, and an ohm meter to test the sending unit. New sender, problem solved. But it took time to diag the thermostat....which techs often don't recover because of using "flat rate" labor.

 

[85Hokie]

I quit relying on IR guns.

IR reads surface temp. Often the coolant inside is considerably hotter. It takes a while for the surfaces that the coolant is running through to equalize temp with the coolant that is passing through. With cast iron and especially stainless, a LONG while.

They've fooled me many many times. Had an issue with the race car a while back and hit each of the header tubes with the IR. They all showed around 560 deg F. But EGT bungs showed 1140 on 7 cylinders, and #6 was around 780. #6 was NOT firing at all. Just blowing hot air and fuel out of it that had passed through the cylinder. if I had let it sit and run a while the temps on #6 would remain lower than the other 7, BUT it takes a hot minute to do so. Stainless headers with coating on them. The whole time, drinking fuel-probably take a half gallon of fuel or more to get to that point.

I've also had them fool me in many occasions in diagnosing overheating issues. M9540, thermostat housing reads 145 degrees on both sides. Ok it's stuck open. Took it out, no it wasn't. Really wasn't anything wrong but the sender was not functioning properly as verified by hot water, a thermometer, and an ohm meter to test the sending unit. New sender, problem solved. But it took time to diag the thermostat....which techs often don't recover because of using "flat rate" labor.

As much as I understand your data and your knowledge - the top of the radiator and the bottom are both thin walled aluminum or copper, both transmit heat at an amazing rate, liquids will get those two metals up to temp quickly too.

While the laser at a longer distance CAN get a "off" reading, placing the laser at 6" is going to get a reading that is damn close to what is going on. IN my case, the reading IN the upper radiator hose was measured at 210 ish, and the digital readout on the laser was 216, so that works for me.


Am I saying it is 100% accurate - NO, but in this case it will give you data that tells what is going on inside and though the cooling of the radiator. And there is the answer I am looking for, HOW MUCH cooling IS the radiator doing?

With these thermosyphon systems - a clean INSIDE and OUTSIDE will get good cooling - whereas chafe on the outside or crud on the inside will get you are cracked head quickly.

 

[lugbolt]

somethign else worth mentioning is...radiators.

A lot of these antiques used a copper radiator. Right? Copper is a good conductor of heat and electricity. We know that. But what holds the radiator together?

It's not just copper. It's a copper/brass/lead radiator not a copper radiator. And sometimes add steel to the mix for the framing/mounting. The lead and brass don't conduct heat very well. Steel is the same way. So the copper/brass/lead radiators aren't all that stelllar in heat transfer by comparison to more modern Aluminum cores.

There is a reason that automotive manufacturers went to using aluminum cores for radiators and heater cores, and it's not solely due to cost concerns either. Even aftermarket, hard to find copper/brass/lead replacement radiators anymore.

All that said, to say this: I'm kinda curious, do they make an aluminum radiator for these old tractors? I don't know, just asking for my own curiousity.

 

[slyoteboy]

somethign else worth mentioning is...radiators.

A lot of these antiques used a copper radiator. Right? Copper is a good conductor of heat and electricity. We know that. But what holds the radiator together?

It's not just copper. It's a copper/brass/lead radiator not a copper radiator. And sometimes add steel to the mix for the framing/mounting. The lead and brass don't conduct heat very well. Steel is the same way. So the copper/brass/lead radiators aren't all that stelllar in heat transfer by comparison to more modern Aluminum cores.

There is a reason that automotive manufacturers went to using aluminum cores for radiators and heater cores, and it's not solely due to cost concerns either. Even aftermarket, hard to find copper/brass/lead replacement radiators anymore.

All that said, to say this: I'm kinda curious, do they make an aluminum radiator for these old tractors? I don't know, just asking for my own curiousity.

It would be pretty slick if be-cool made a drop in AL radiator.