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Cab heater on an X728

6K views 11 replies 6 participants last post by  300sflyer 
#1 ·
I just picked up an X728. I'm building a cab for it and want to put a heater in it by tapping into the engine coolant. My concern is that the radiator draws its air from the cab area and has the potential of negating the effect of a heater by pulling warm air out of the cab. Has this been an issue for anyone using a heated cab?
I'm thinking of two possible solutions. One would be to fab up a plenum to feed air to the radiator from outside the cab. The other is to install a radiator fan with reverse pitch blades that actually force warm air into the cab. I did this on my old Kubota and it worked great. Problem is finding a fan with the correct diameter, shaft mounting and pitch. Any thoughts?
 
#2 ·
DOH! Just did a search and found a post with almost exactly the same question. Solutions were to block off the air intake (???) or install a reverse flow fan blade, similar to what I did on my Kubota. I'm not crazy about the idea of blocking off air flow to the radiator so I'm opting for the reverse air flow fan blade approach. So now the question is, does anybody have a suggestion for a reverse pitch blade that will bolt up without too many modifications? For my Kubota I had to scour through a junkyard to find something close and that turned out to be from a Datsun 510, believe it or not.

As an option, I thought about replacing the engine driven fan with an electric one. This way I could switch it from a pusher (heater) to a puller (cooling) just by reversing polarity.
 
#3 ·
I just picked up an X728. I'm building a cab for it and want to put a heater in it by tapping into the engine coolant. My concern is that the radiator draws its air from the cab area and has the potential of negating the effect of a heater by pulling warm air out of the cab. Has this been an issue for anyone using a heated cab?
I'm thinking of two possible solutions. One would be to fab up a plenum to feed air to the radiator from outside the cab. The other is to install a radiator fan with reverse pitch blades that actually force warm air into the cab. I did this on my old Kubota and it worked great. Problem is finding a fan with the correct diameter, shaft mounting and pitch. Any thoughts?
I would think if the engine cooling fan is reversed in direction, it's going to be difficult moderating the temp in the cab.

Also, using the cooling system as it's designed and drawing much of the air needed for engine cooling across the radiator would seem to make the challenge of making your cab air tight even more difficult. I can see where a "make up air" source for engine cooling air from outside the cab would help reduce the air draw from inside the cab and cuts down the "drafts" of pulling the outside air into the cab through cab seams, door openings, etc.

The entire area inside the cab is maybe 45 to 50 cubic feet (assuming the cab is roughly 3 feet square and 5 feet tall in height from the platform height....) and that area will tend to heat quickly. It would seem easier to adjust the water flow into the heater core and control the blower motor air flow than trying to regulate the warm air from a cooling fan blowing the opposite direction across the engine radiator towards the operator inside the cab.

It doesn't take much to heat such a small space if its fairly air tight. With my heater in my cab, even at temps below zero, I can't run the heater on high for more than a few minutes upon start up or the cab gets too hot very quickly. I have a flow control valve which I can adjust to reduce the flow of warm water into the heater core and usually, that valve is closed 1/2 or more much of the time. The flow control valve is probably the most important part of controlling the cab temps, with the blower motor being next.

I would try the cab heater using the heater core, coolant flow control valve and a multi speed blower motor and see how it works before modifying the tractor's cooling fan. I think that heater core as a heat source and the blower motor will be more than adequate for the cab heat.

Just curious, what material are you using for the cab sides and roof panel? If you don't mind, Please post pictures of your cab and details as you are fabricating it as this is always a popular topic this time of year.
 
#4 ·
Thanks Sulley and you are correct about controlling temps with the reverse flow fan. With the Kubota I had to keep the door open whenever the temp hit the mid 20's, but I was happy to put up with a little too much heat when I was comfy at zero.

Right now I'm looking for the simplest, quickest and cheapest solution and that may well be the dedicated coolant heater. I was a little concerned about tapping into the coolant lines until I ran across an old post that provided a link, [URL="http://www.cozycab.com/wp-content/up...3/05-11243.pdf"/URL] that provided a great step-by-step process for the hookup.

As for the cab, I'm building it out of simple materials, 1x4 framing, 1/4" plywood sides, 3/8" plywood roof, plexigas. I've done three of these before, on a Bolens, a Kubota G1800 and an x345. They all worked out great and had the added benefit of being light and simple to mount and dismount. My wife (120# soaking wet) and I could easily do it ourselves. Four screws, one at each corner holds it in place. A guy with a 730 in a previous post said he needed four guys, one at each corner to remove his Curtis cab. I hope to start my cab tomorrow and I'll be happy to document the process on a separate thread.
 
#7 ·
Thanks Sulley and you are correct about controlling temps with the reverse flow fan. With the Kubota I had to keep the door open whenever the temp hit the mid 20's, but I was happy to put up with a little too much heat when I was comfy at zero.

Right now I'm looking for the simplest, quickest and cheapest solution and that may well be the dedicated coolant heater. I was a little concerned about tapping into the coolant lines until I ran across an old post that provided a link, [URL="http://www.cozycab.com/wp-content/up...3/05-11243.pdf"/URL] that provided a great step-by-step process for the hookup.

As for the cab, I'm building it out of simple materials, 1x4 framing, 1/4" plywood sides, 3/8" plywood roof, plexigas. I've done three of these before, on a Bolens, a Kubota G1800 and an x345. They all worked out great and had the added benefit of being light and simple to mount and dismount. My wife (120# soaking wet) and I could easily do it ourselves. Four screws, one at each corner holds it in place. A guy with a 730 in a previous post said he needed four guys, one at each corner to remove his Curtis cab. I hope to start my cab tomorrow and I'll be happy to document the process on a separate thread.
Did the prior enclosures stay with the tractors when you sold, traded or whatever happened to them?

Regulating the coolant flow through the heater core with a cable controlled valve would also be very easy and a great way to regulate the temps with consistency. Many of these units are self contained with the blower motor, the core and the control valve in a plastic housing which would simplify the mounting of the unit on the outside of the tractor enclosure, keeping it out of the way of the operator.

I would also consider the secondary heat systems used in the rear seat areas in many SUV's, vans, etc. These have been in use for many years so they should be available through salvage sources. Some I have personally worked on had smaller diameter heater hoses supplying them, which would simplify the routing and connection to your tractor's coolant lines.
 
#5 ·
Maybe you could incorporate the air dam used in the curtis cabs that take the outside air from the front of the cab and you wouldn't need to deal with the fan reversals and such.. Can't be hard to do if you can build a cab in the first place and you may even be able to purchase the shroud from Curtis? (it will be a custom fit piece around your hood). Can't be that expensive and it would solve your problems... Just a thought.
 
#8 ·
Yeah, I sold all the enclosures along with the tractors. In fact, they were a big factor in the sale all by themselves. I am looking at one of those self-containerd core/fan/regulator on Amazon. For $50-60 buck, can't beat it.

Thanks for the suggestion of posting my cab build. First installment to follow.
 
#9 · (Edited)
So something did cross my mind. If you could find a way to put the radiator and you and the fan all in the enclosure and seal it up, less the exhaust gases obviously, you would probably end up with a well heated cab and a more optimum performing engine by not slamming the radiator with such cold air, thus increasing thermal efficiency by allowing the motor to get warmer than just an open set up. Would surely need noise canceling headphones.

On second thought, reverse flow fan, turns your throttle into your heat controller [emoji848]

Sent from my SM-N950U using Tapatalk
 
#10 ·
Take a look at how Cozy Cab does their X7xx series cabs. The last time I looked you could download the mounting instructions, etc from their website.
 
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