B Radiator

[arlen]

The radiator shop called today, and said my radiator had multiple leaks on both the core and the tank. It also has a badly damaged filler neck that I was hoping they could repair (if that was the only problem). It is not worth repairing in their opinion. So they are sourcing me another non pressurized one for a replacement. I got to thinking if I should have went with a pressurized replacement.
It ran for over 70 years with that one, so I'm thinking a non pressurized one will be fine.
What are the pros/cons of a pressurized system in conjunction with the thermo siphon system?
Another $450.00 to the total
There ain't too many more things that can bite me on the engine now, pretty much everything has been inspected, and/or replaced/repaired.

[Don McCombs]

Do you have a water pump?

[arlen]

Do you have a water pump?

No. It is the original thermosiphon system. Does that have to use a non pressurized radiator?

[Jim Becker]

Water pump vs. pressure system: totally independent concepts.

[arlen]

Water pump vs. pressure system: totally independent concepts.

I understand they are not the same thing. I guess my question was...will the thermosiphon system work with a pressurized cooling system, and if so, does it offer any advantages over the
current system that operates at atmospheric pressure?

[Jim Becker]

Pressurizing the system allows it to work at a higher temperature before the coolant boils. That is true whether you have a water pump or not.

[arlen]

Pressurizing the system allows it to work at a higher temperature before the coolant boils. That is true whether you have a water pump or not.

What does a water pump have to do with a thermo siphon system? Why does everybody keep asking about a water pump on a tractor that doesn’t have one? Ok, I guess I have to spell it out...
Does anybody on this forum run a pressurized cooling system on their thermosiphon tractor?

[outdoors4evr]

It doesn't matter whether you use a pressurized cap or not. It seems to me you have two options:
1) Recore and repair the existing radiator
2) Purchase a new radiator.

Seems to me I wouldn't exceed the cost of a new radiator. TM sells the Clancy radiator for $188.20 + Shipping.
http://www.tmtractor.com/new/co/671fp.htm

[Gary Dotson]

Yes, Arlen, I have run a pressure cap on a thermo syphon system, on my old Cub. There is no difference in operation other than the fact that pressure system can run at higher temperature before boiling of pushing coolant out. On my Cub, it made no real difference. if your "B" is going to work hard for it's keep, the pressure cap might be a nice upgrade, otherwise, will make no difference at all. My oldest Kubota tractor is thermo syphon, with a pressure cap, from the factory, it wasn't happy with a bad cap, but it's designed to have one.

[arlen]

Yes, Arlen, I have run a pressure cap on a thermo syphon system, on my old Cub. There is no difference in operation other than the fact that pressure system can run at higher temperature before boiling of pushing coolant out. On my Cub, it made no real difference. if your "B" is going to work hard for it's keep, the pressure cap might be a nice upgrade, otherwise, will make no difference at all. My oldest Kubota tractor is thermo syphon, with a pressure cap, from the factory, it wasn't happy with a bad cap, but it's designed to have one.

Thanks! I appreciate actually answering the question at hand. It’s a rare talent I’m finding out

[arlen]

Yes, Arlen, I have run a pressure cap on a thermo syphon system, on my old Cub.

The radiator filler neck itself has a little different of a design for the overflow tube for the non pressurized application doesn’t it? Or is it just the cap?

[arlen]

Yes, Arlen, I have run a pressure cap on a thermo syphon system, on my old Cub.

To your earlier point on working the B hard. We will just be raking hay with it and pulling wagons around. My father in law tortured it without mercy for 70 years, so it won’t be working that hard. He would overheat it occasionally, and would put creek water in the radiator when it would boil over and be low on coolant.
With all the engine work I’m doing and a new radiator, it should probably run cooler than it has in several decades

[Eugene]

Search this site for (block flushing tool).

If you haven't done so, you need to remove built up crud from the cooling system. Crud builds up around cylinders 3 and 4, causing over heating and scored cylinders.

[Super A]

Yes, Arlen, I have run a pressure cap on a thermo syphon system, on my old Cub. There is no difference in operation other than the fact that pressure system can run at higher temperature before boiling of pushing coolant out. On my Cub, it made no real difference. if your "B" is going to work hard for it's keep, the pressure cap might be a nice upgrade, otherwise, will make no difference at all. My oldest Kubota tractor is thermo syphon, with a pressure cap, from the factory, it wasn't happy with a bad cap, but it's designed to have one.

Thanks! I appreciate actually answering the question at hand. It’s a rare talent I’m finding out

Sometimes formulating an answer requires some additional information. As and Bs sometimes got retrofitted with water pumps. Anyway......

Later replacement radiators from IH for the A/B/Super A/C were all designed to run a pressure cap and they were all thermosyphon. I don't think it makes much difference in terms of working the tractor, assuming the rest of the cooling system is in good shape.

Both pressurized and non-pressurized have an overflow tube. The earlyish A and B didn't have a notch cut in the grille's radiator neck hole for the overflow, but I'm not sure it even mattered. The neck of the radiator is different to accept the pressure cap. Non-pressurized radiators have a neck more like the neck on the gas tank.

Al

[Urbish]

I began running a pressure cap on my B after I began mowing with it as during 'spirited' turns sometimes coolant would be slung out of the overflow tube. I have run low pressure caps on my B and both of my Cubs. I discovered a rotten hose (cleverly disguised by a thick layer of paint) after installing a pressure cap on my LoBoy as it blew almost immediately.