Load, hell yes. But cooling will need to be thought out carefully. An all-aluminum open deck motor isn't going to be tolerant of overheating. Cooling is your problem. A few fine points about cooling on these engines:
- this isn't really a 12, it's more like two sixes arranged on a common crank. The significance of this is that there are water exits in each head, each controlled by a separate thermostat. The killer on these motors is that the temperature sensor is on the right bank, which means that the thermostat on the left bank can be stuck closed and you will only notice a slight rise in temperature. Since you have a custom application, I strongly urge you to have two temperature gauges, one measuring output temperature on each bank.
- A consequence of the two-thermostat design is that the valve seats on the left bank tend to drop, that's what you need to be concerned with on a used motor.
- The primary native applications, XJ6 and XJS, had limited fontal area, decending hood lines and cramped space. This resulted in the most compromised radiator design in Jaguar's sad history of cooling system compromises. The radiators are small for the application, and they are a weird combination of two pass and one pass. ( The left bank flows from left to right in the upper rows, then joins the right bank flow, which then flows right to left in the lower rows).
-The radiators were also mounted lower than the motor, so there are bleed ports that probably won't be useful to you. But owners often overlook bleeding the radiators, so it's not unusual for them to be run with low coolant levels. Another result of the mounting is that the water exit is above the bottom of the radiator. It's just weird.
- Oddly, the radiators werent redesigned over 20 years of production. As a result, the best radiator to use isn't the modern design, but the big radiator from the original V12 E-Type. (I can hook you up if you need help with this). Second choice would be the BeCool single pass XJS radiator.
- Kirby Palm's XJS help book has a lot of useful information on this motor. You can download it free here:
http://www.jag-lovers.org/xj-s/book/XJS_help.pdf