Radiator Cap for Cub with 184 motor

[ShawnAgne]

Finally mowing again with my Cub after not really using it past two years. Its only seen light duty polowing snow in the cold so motor is never really running hard. Well this summer got the deck on it and decided to work it. Last week didn't get much mowing done as lost a belt on the deck, replaced it and was able to do more. Last week had some steaming but figured ok its just finding correct level and excess is steaming off. Well today was mowing and eventually decided to quit because while it wasn't heavy steam seemed to be a good bit. When I shut it down it was hissing and good bit of steam. Definitely sounded like there was bubbling going on in radiator.

So I'm not sure its circulating, motor is one built by Art and its not clogged and I had pulled the radiator 2 years ago and cleaned it out. I'm using a non pressurized radiator cap on it. Since its a 184 motor and the 184s had a pressurized cap should I be using a pressurized cap?

Edit I added 1/2 gallon of coolant which got it up over the tubes. I didn't check the level before I started mowing today, so maybe it was already low and caused the over heating?

[Mht]

Mine does the same thing when worked hard mowing. I bought a cheap infrared thermometer from harbor freight so I could see what the actual engine temps were. I found the actual engine temp was fine. I purposely fill my radiator regularly above the level that the engine normally seeks and as long as it’s spitting out some water and steam I don’t worry about it. I’ve done this for the past three years and never had any heat related problems. I run non pressurized caps on all my cubs because that’s what hey came with and they all have old radiators and I don’t want to have to buy new ones that don’t seem to fit correctly many times. An infrared thermometer costs less than 20 bucks and is cheap piece of mind as far as I’m concerned

[ShawnAgne]

I do have an infrared thermometer. Where should I measure and what temp range should I expect?

[Eugene]

Warm day, 200 degrees, plus maybe a few more degrees.

[Mht]

I measured the temps at several places on the engine. Cylinder head, several spots on the upper part of the block, upper and lower radiator hoses. I figured the upper radiator hose temp gave me the info I really needed but checked temp
In numerous places just out of curiosity. I don’t think I saw any temps outside that 200 degree range either and saw about a 20-25 degree difference between upper and lower radiator hoses which gave me confidence my radiator was clean and performing properly

[Gary Dotson]

If you’re sure your cooling system components are sound, you can run a pressure, just stay with a fairly low pressure 4-5 psi. Keep in mind that most Cubs have deeper radiator neck than typical auto applications. Measure yours before you go shopping. I’ve used a pressure cap, in the past, and didn’t really notice much difference. Check cooling system components: fan belt must be snug, shroud in place, radiator free of debris and of course coolant level every time you mow.

[outdoors4evr]

I cut the gasket on my 184 to reduce the pressure cap to zero. I do have to remove the grill often and clean the grass out of the radiator screen. It will boil the antifreeze after an hour of low airflow.

[Dale Finch]

I cut the gasket on my 184 to reduce the pressure cap to zero. I do have to remove the grill often and clean the grass out of the radiator screen. It will boil the antifreeze after an hour of low airflow.

I made these several years ago and they are really great! Since I have 11-bar grills on my mowing cubs, a lot of chaff got caught between the bars and screen, plus a lot got through to the radiator. You're right, having to remove the grill all the time is annoying. Now all I do is either unhook the little bungees & shake the grass off or simply sweep it off in place with a broom.
http://farmallcub.com/phpBB2/viewtopic.php?f=1&t=94176&hilit=Radiator+screen

[ShawnAgne]

If you’re sure your cooling system components are sound, you can run a pressure, just stay with a fairly low pressure 4-5 psi. Keep in mind that most Cubs have deeper radiator neck than typical auto applications. Measure yours before you go shopping. I’ve used a pressure cap, in the past, and didn’t really notice much difference. Check cooling system components: fan belt must be snug, shroud in place, radiator free of debris and of course coolant level every time you mow.

I think this was the issue I didn't check the coolant level. I have it just above the tops of the tubes now, so will give it a go next time and see how it goes.