didnt realize ron was gonna get his panties in a wad.

 

BOY are you in for a surprise,, i.m betting it will run even hotter than before, you removed the stock thermostats and put a restrictor in the in the HI-FLOW part of the housing!! right?

what about the small cool flow BYPASS hole, so that you have coolant flow when cold, not shut off completely, it can cause localised hot spots?

if you are having heat probs. and want to run without stats, you have to block the bypass holes, and do not run restrictor plates!!

many guys long before you were born, have made heat control mods,, a guy in Australia, LUTZ, has a cooling mod that does help Jag V12 run cooler.

you do have a lot to learn about cooling systems.

and that old world BS about slowing the coolant flow, is the laughing stock of the world!
its a circle track mod for cars that run in a short rpm range,they dont have to idle in hot traffic, and on the I-states they dont have to cruise for hours at hi-speed, where a lot of coolant flow is needed!

stop and think, the faster you run the engine<loaded> the more coolant you need to cool it, slowing the flow only allows the coolant to get hotter, and boil!

some times i feel as tho im teaching school again!! haha

 

Not sure how this is an "upgrade" to be honest.

Notice how the back side of the thermostats have the bypass disc? With the restrictor plates in place you've eliminated that function. You might wanna do some research as to what problems this might cause. I can't remember the details but as I recall it's important. I'm sure the specifics are in Kirby's book.

The idea of the coolant moving to fast to cool down has been disproven many times, by the way.

Cheers
DD

 

if thats true then i might as well run without anything. you dont have to be a jackass about it.

and the idea is that the coolant is moving too fast to heat up.

 

Best bet, really, is to run the correct thermostats. You want the rear disc and a steam hole at the 12:00 o'clock position. Some have the hole, others don't. Some have a jiggle pin, others don't.

You can drill a hole easily enough. The jiggle pin isn't essential.

Cheers
DD

 

I have come into this discussion pretty late, so I will pass on the knowledge I have gained from talking to a couple of guys here in Aus that have modified their cooling system to great effect.

There is a restrictor mod you can do to the water rails that entails adding orifice plates to the input of the water rails - smaller holes at the front getting larger to the rear of the rail. What this does is allow more water to flow through the rear of the V12 to even out front to rear engine temperatures, this mod is really only needed for highly modified engines. TWR did a similar modification to the XJS group A cars.

Under NO circumstances run the V12 without thermostats (unless you run an electric water pump), as it will cause overheating. The thermostat acts like a 3way valve.

When cold it bypasses the radiator and recirculates water directly to the water pump inlet.

When hot the thermostat opens effectively blocking off the bypass and allowing water to pass through the radiator.

Flow is the key to cooling (if everything else is ok) increasing the flow will help with cooling. I learned this from working on large watercooled IBM mainframe computers.

If you have overheating issues do the basic stuff first clean between the radiator and AC condenser, clean the radiator and check the fan clutch (when hot turn the engine off and it should stop in a turn or two)

hope this is helpful