Farmall H- what should I see when I pull the radiator cap?

[Cubcadet_107]

Thermostat has been ordered. Unfortunately despite looking for quite a while I did not find anyone selling a 180 degree one. So, 160 degrees it is. Better than no thermostat at all. Now I need to wait for it to arrive and find time to install.

[Cubcadet_107]

Thermostat arrived in the mail today, however upon opening it I immediately see what looks like a potential issue. The thermostat is in 2 pieces.
IMG_20211117_203159.jpgIMG_20211117_203152.jpg

To me it looks like it didn't get pressed together correctly. I would assume its supposed to be all one piece, but I really don't know for certain. If this IS defective can i fix it or do I need another? If I need another, should probably get the replacement for free if this thing is defective like this

[docmirror]

That's no good. This is what you need:

https://www.yesterdaystractors.com/F...tat_R1852.html

My opinion is the 160F thermostat is the correct for your type of oil, and the oil passages in your tractor. 180 will just thin the oil, and may not lubricate enough for the looseness of many old tractor engines. These are not the new sewing machine engines which can use 0-20 weight oils. 160F will drive off the engine condensate just fine if used for a half hour or so.

[Cubcadet_107]

Originally Posted by docmirror

That's no good. This is what you need:

https://www.yesterdaystractors.com/F...tat_R1852.html

My opinion is the 160F thermostat is the correct for your type of oil, and the oil passages in your tractor. 180 will just thin the oil, and may not lubricate enough for the looseness of many old tractor engines. These are not the new sewing machine engines which can use 0-20 weight oils. 160F will drive off the engine condensate just fine if used for a half hour or so.

That's what I was thinking. Amazon is going to send a replacement free of charge but, I am not expecting much . I questioned the same thing on another Cub forum and got the same answer. I have not started the tractor since discovering the issue, still waiting until I can get a new thermostat installed and functioning properly. Especially now, since there's currently about an inch of snow on the ground.

As for temperature, the Amazon replacement (which is likely identical to the one you've linked but with less quality control) is a 160 degree unit. I've heard mixed views on the temperature. A lot of people seem to agree that 180 is better for the unit. In fact on the other forum I asked this question, I was given info of a 180 degree thermstat avaliable at Autozone that works in place of the original. I'm unsure what oil you think I'm running in the engine, I changed the oil in it about a month ago and, as winter approaches, I followed what oil diagrams for the H told me and went with 10w-30 for the cold climate. Otherwise would have went with plain ol' 30wt. I also don't think tolerances on these old tractors are that sloppy, nor do I know what you mean by "sewing machine engines".

[docmirror]

Originally Posted by Cubcadet_107

That's what I was thinking. Amazon is going to send a replacement free of charge but, I am not expecting much . I questioned the same thing on another Cub forum and got the same answer. I have not started the tractor since discovering the issue, still waiting until I can get a new thermostat installed and functioning properly. Especially now, since there's currently about an inch of snow on the ground.

As for temperature, the Amazon replacement (which is likely identical to the one you've linked but with less quality control) is a 160 degree unit. I've heard mixed views on the temperature. A lot of people seem to agree that 180 is better for the unit. In fact on the other forum I asked this question, I was given info of a 180 degree thermstat avaliable at Autozone that works in place of the original. I'm unsure what oil you think I'm running in the engine, I changed the oil in it about a month ago and, as winter approaches, I followed what oil diagrams for the H told me and went with 10w-30 for the cold climate. Otherwise would have went with plain ol' 30wt. I also don't think tolerances on these old tractors are that sloppy, nor do I know what you mean by "sewing machine engines".

Old tractor engines are 'loose'. The ring gap, the piston fit, the crankshaft bearings, cam bearings, valve train, basically all lubricated components have much larger tolerances than a modern Honda or Toyota engine. That's why modern engines use a very thin oil, so that it can maintain surface tension inside the tight confines of the lubed passages.

Your Toyota engine will happily run for hundreds of hours at 5000RPM if you want it to. Your Farmall H engine is rated for 1650RPM, and red line is about 2100. Hence the 'sewing machine' moniker for 0-20W oils in modern engines.

Viscosity modifiers in modern oils allow the additives to expand under temp increase and maintain proper oil pressure. 10W-30 will work from -5 to about 80F. If one were to run a higher temp thermostat, the engine oil will also run 20F hotter. That means, 20F will change the viscosity to a thinner viscosity, and possibly not maintain the surface tension needed due to low pressure at the end of the oil circuit. One may find that the difference on the gauge is about 10PSI. That's possibly fine where the bearings are just upstream from the pump, but by the time the oil is delivered to the valve train, it may begin to not flow enough to prevent metal contact.

The other issues that's not discussed much is windage. Inside the crankcase, there are very large, very heavy, very bulky things going around. With the thinner oil, there will be more air entrained in the oil returning to the sump, which means more air pulled into the pump, and more air entrained in the oil galleries. This is a bad thing. Bubbles of air in the lube as it moves around the circuit can mean metal to metal contact where the air displaces the oil as it expands after being compressed in the oil pump. Again - the start of the circuit won't be affected but by the time the oil/air is at the end of the passages, there may be more air than oil, as the air heats due to adiabatic pressure increase, and lower pumping pressure.

If you want to test it yourself. get both temps, fill as recommended, then go out and use the tractor for an hour. Then, set the tach to about 1400, let it stabilize and check the oil pressure carefully. Change over to the other tstat, and run for another hour, then recheck oil pressure at the same RPM. I'm quite sure you will see a difference.

Finally, hotter temps are lower power. As air is heated, it thins. So 180F allows for fewer molecules of air to be sucked into the carb, and lower compression pressures, meaning lower power produced at RPM. Cold air works better than hot air, every time.

[Cubcadet_107]

I'm not going to argue with you, its not my place. I'm not experienced with these tractors as I've only owned this for a couple months. The only thing I'm going to note here is that I've got you, telling me to stick with the 160 degree thermostat, vs about 5 people from here and a different forum telling me to go with the 180 degree unit. Not really sure who to believe at this point

[docmirror]

I'm ok with that.

Have a nice day

[ol'George]

*160-180 were the norm in the pre 50's,
When emission engines began to appear they went to *190 195.
You will not go wrong with using *160.
Also in the early days the temps had to be kept lower because the methanol/alcohol antifreeze boiled at lower temps than the permanent type containing ethylene glycol.