Radiator hose heater on a Kubota BX, PICS and warming data

KYKub · Feb 14, 2016

I really wanted to install a block heater on my BX1860 but, due to clearance issues (i.e., muffler too close to freeze plug), the dealer-provided heater is one that goes in the lower radiator hose.

Since I could find no photos online, and very little information, I thought somebody might benefit from a summary.

The lower radiator hose is hard to access; it's tight in there! Instructions say to install in a "straight" area of at least 3 inches. I couldn't see any way and had to work it into a bend. Had to use a light torch to soften the hose.

Couldn't keep the heater from touching the oil filter. Since it gets very hot I wedged a piece of radiator hose between the heater body and the filter. I'll do something more permanent later.

A picture from the other side, showing the heater plug orientation.

So, how does it work? A very cold day here. Temperature is 15 degrees with a slight wind. Tractor is outside with the hood open and lower shroud off. Using IR thermometer, the block was 21.8 degrees when I plugged in the heater.

after 30 minutes: front of block (front of machine, farthest from heater) = 26 / rear of block = 36
after 60 minutes: front = 32 / rear = 40
after 90 minutes: front = 35 / rear = 48
after 120 minutes: front = 32 / rear = 47
after 160 minutes: front = 38 / rear = 51
after 190 minutes: front = 35 / rear = 49

It seems that little is accomplished after 90 minutes or so.

I'm not sure how this compares to a true block heater. I have one on another machine with the same engine but have never measured it. An hour or so seemed to warm the engine nicely.

Indoors, out of the wind, and with the hood and shroud on would probably slow the dissipation of heat from the engine block and allow the heater to work more efficiently.

Overall, I guess I'm moderately pleased with the heater. Would still prefer traditional block heater, but that's not an option for me. If the outside of the engine block is 35-50 degrees, the inside must be reasonably warm. Certainly better than nothing.

Tractor always started fine without a heater, I just wanted to be kind to it on cold days.

KYKub · Feb 14, 2016

An update: after replacing the shroud and closing the hood, the block was considerably warmer. Measured 60 degrees at front and 70 degrees at rear of engine. Opened the oil fill cap and measured inside the block - 67 degrees. Outside temperature was warmer--25 degrees--than yesterday, but still a nice improvement. Pretty pleased with the result.

oldnslo · Feb 15, 2016

Nice job KYKub,
I don't remember the quick disconnects being in that location on my BX1850 when I installed the heater unit but them I don't recall what I had for breakfast either ....

RalphVa · Feb 15, 2016

That's a tight fit. Had one on the lower heater hose of our 220D Benz. Worked fine to warm the engine in 30 minutes in -22 F weather one day in Vermont.

Ralph

JWR · Feb 15, 2016

KYKub said:
An update: after replacing the shroud and closing the hood, the block was considerably warmer. Measured 60 degrees at front and 70 degrees at rear of engine. Opened the oil fill cap and measured inside the block - 67 degrees. Outside temperature was warmer--25 degrees--than yesterday, but still a nice improvement. Pretty pleased with the result.

Yes, I'd say you did well. And when you think about it the best measure of how warm your engine is (or is not) is the coolant temperature and that is exactly what you are warming up. I think the reason you see no further change in temp after a couple of hours is that the in-line heater has a built in thermostat and shuts on and off after a while. When I used them on VW diesels back in the 80's I left it plugged in all night. BY THE WAY a key point with circulation heaters is that the engine thermostat has to be open enough to allow coolant flow thru the block. Evidently you got it in the right place based on your IR temp measurements. It is a common goof to install the things such that you are heating the contents of the radiator really well and having no effect on the block whatsoever !