Kibert…thanks for all of your input. A good suggestion to replace the heater fitting with a way to mount a coolant sensor switch as was your suggestion to isolate the fans.
Mmmm…how to determine which fans to install…right now I’m looking at this rig which delivers 4000 cfm with 11X12" blades although I’m still researching. $250 seems about right for the higher output.
I didn’t actually go this route, but I pondered the idea of using two 16" fans, one about where the existing belt-driven fan is and the other in front of the A/C condenser as a pusher, located over toward the port side of the rad. Hence, the two large fans could overlap without interference, enabling the use of 16" fans rather than the smaller fans used in these dual-fan kits. There would be no shroud at all on the fan in front of the rad and only a minimal shroud on the puller, thus maximizing the blow-through of air when travelling at highway speeds.
There is a diagonal brace in front of the A/C condenser. It might need to be fiddled with to tuck a low-profile pusher fan behind it.
Very interesting alternative and well worth a look. did you find 16" blade fans?
Chris
Like I said, I didn’t actually do this. The fan I installed, shown on that page I linked to, was a 16" out of a GM car of some sort. Doesn’t come in a pusher form that I know of, and it is not low-profile, so it was fortunate that removing the belt-driven fan and associated belt and idler left lots of room for the new electric fan.
BTW, the GM fan was rigged with a 2-speed arrangement in the original GM car. High speed was connected directly to 12V, low speed had a resistor in the line, mounted right on one of the fan support rails so the fan running would help cool the resistor. I wasn’t interested in that so I ditched the resistor and operated the fan on full power only. Coming down my driveway, it would clear the leaves off my driveway.
More research today has simplified the installation. Apart from the fans and to avoid overly complicated wiring with a couple of standard 12V relays, this BMW temperature switch plumbed into the ex-water heater connector will allow for automatic switching from 176 deg F to one fan and 190 deg F for the second fan. The AC fan switch would be connected to the first fan. Early days on this project and enough for today (these notes are for sharing and building an eventual parts list 
Possible connector (the BMW switch is 14mm so will need to convert from NPT in the connector
Careful there. Ideally the sensor should protrude into the flow. Use of an adapter may retract it out of the flow. It would probably still work OK.
The diagram on those relays does not indicate a diode or resistor. I recommend installing a tiny diode across the terminals to the relay coil. This will help the durability of the contacts within the temp switch. It’s easy to tell which way to connect the diode; if you connect it the wrong way it forms a dead short and immediately vaporizes.
So its not only Lucas who use smoke 
Gentlemen,
From brief review of the topic it seems to be more affordable to replace v12 with AJ6 3.6…
Just been thinking about hundred yards of coolant hoses in V12 edition… would it be convenient to place inline water pump on one of those coolant lines to force more coolant into the heat-affected zones… ?
Higher flow through the radiator (with increased pressure probably) would solve the problem as well…
Thermostats are warm-up devices. They are not extra cooling devices by selecting a lower range. They are therrfore pointless to change in an overheating/borderline cooling car. . The cooling capacity of the system must be sufficient to keep the thermostat in play…
Thank you for this: Ive tried to enforce this notion for 45 years.
People still believe otherwise.
And people still remove their thermostats, as has been reported on this list, because they believe that this will somehow help engine cooling.
Paul
Waaay back in the day, SWMBO took her Toyota to a respected shop for service and they removed her thermostat! Fortunately they also returned all removed parts, so I just put it right back in!
One time my dad drove from Tampa to Orlando to visit me and when he arrived he complained that his 1969 Volvo wasn’t running right, he had to keep the manual choke on to keep it running. He said it was especially aggravating since it had just been in the shop for a tune-up. I opened the hood and the engine was stone cold. I kid you not, it was room temp. Sure enough, no thermostat. And the Volvo cooling system was clearly more than adequate. I learned later that it was common to drop a V8 into a Volvo and just leave the original Volvo radiator in there, it was more than sufficient.
The thermostat ALSO gives you a desired temperate to drive at. Once you’re moving and the cooling system is more than adequate, the thermostat keeps the car at a steady temp. I have 180F thermostats, and like driving at that temperature. It’s warm enough for the EFI to be in full warm up, but not too hot. The standard thermostat is 195F in the US (I think), and although that’s fine to run the engine at that temp, the extra 15F IMO adds to the under hood temperatures which affect wires, hoses, and especially the ignition amp.
If you’re not a V12 guy, then maybe it’s not for you. But "replace v12 with AJ6 " is not something to contemplate lightly. If that’s your goal, by a 6 cylinder car, swap whatever bits that will give you one good 6cyl car, and sell/part out the V12 car.
I’ve thought about an inline water pump, but only to help reduce heatsoak on cool down. The problem is where to put it in all that complex plumbing.
You can shed heat via the radiator and raise the underhood temp, or you can raise the engine temp directly by passing less to the rad. What you can’t do is substantially magic the heat away from the engine compartment, unless you re-engineer the system. Radiator in the trunk?
I think there has been plenty of previous discussion on adding louvres to the bonnet to help remove waste heat. Not sure what conclusion, if any, was reached.
One thing not addressed in this post is the fact that an aftermarket temperature sensor is being contemplated for the fan switch. You do need to match this to the operating temperature of the engine, otherwise the fan may be commanded to turn on and stay on far more than is necessary.
Typically, cars don’t need cooling upgrades, they need cooling maintenance instead. People report great things from these upgrades, but this is because the benchmark is a failing cooling system which has not been maintained.
A properly functioning cooling system always has more capacity to cool then the engine has to heat. The thermostat systematically throws away this excess cooling capacity by choking off the water supply to the radiator, thus maintaining the minimum operating temperature, so all these upgrades ultimately do is drop the temperature faster, but not more.
kind regards
Marek
Well yes, and you could leave the bonnet off altogether but that wasn’t the issue being addressed. Greg was saying the engine temp difference running cooler tstats helped under-bonnet components survive the heat.
What I pointed out was that without other changes the extra heat removed from the block would basically still inhabit the engine compartment as extra radiant and convected heat shed from the radiator.
The engine produces so much heat energy that the Radiator has to remove.
Running colder the engine will need a little more fuel and produce a little more heat energy, but will get less hot as it will be removed and flow through the engine compartment at a lower temperature. The moving air is always colder than the radiated heat from the engine!
Since the wiring is right next to the engine it will probably be a bit cooler until the engine is shut off and the temperature goes up as the heat inside the engine is released and the manifolds cool down.
I‘d guess opening the bonnet after driving does much more good than a cooler thermostat and after 20-30 years a new wiring loom as maintenance item can’t hurt?