Since I have been on the subject of Cooling I might as well briefly cover my engine cooling plans. The Centurion plans call for using the original Spitfire radiator. In my opinion the Spitfire radiator is overkill for the small Kubota 2 cylinder engine. The Triumph radiator was sized for an engine that was more than double the Kubotas size. So I will downsize and go with a more appropriately sized unit. I have looked into several options and most likely I will go with an all Aluminum dual core unit that are used for Go Karts. They can be found on Ebay for $100.
The advantage of this is 10 fold. I have a radiator that is more compact and light weight. I will also gain the advantage of a dual cores which increases cooling capacity and overall cooling efficiency for the given size. An all aluminum unit typically lasts longer than the newer plastic units they sale for OEM cars these days. There will be less time for engine heat up due to the smaller size. This is one area of a diesel engine that can be improved upon and going with a smaller radiator can help achieve this.
Along with this I will do away with the mechanical water pump and install the electric water pump I have (EWP80). These units are compact and electronically controlled. They control the pump as well as the electric fan. You have multiple set points and the advantage of engine cooling while the engine is off. There are other advantages as well but the main idea is electric efficiency and control. This on a tiny micro engine such as the Kubota Z482 helps preserve its mega 13hp output vs a belted mechanical water pump which robs ponies and is less efficient
Disadvantage to the mechanical water pump is it is running continuously and only when the engine is on. Engine cooling is only really needed continuously when you are in stop and go traffic or being pushed really hard like in racing conditions.
Here is a quick video about the product =