Hi all

Wanted to know if the Norman Lutz Modifications to the cooling rails actually work for hot countries? Anybody have actual proof?

If so where can I get the complete details of the modifications from?

Thanks

Warm regards

 

They work. My temp gauge read higher after it was done, as the cold water from the rad was no longer partially short circuiting; ie( in the front of the engine from the pump and out of the front of the heads past the temp sensor). Thus proving the coolant was being forced more to the rear of the head and hotter coolant was now passing the sensor.
All the V12 racers used this or similar fixes to ensure the rear of the engine got its fair share of coolant.

 

In the end the rear of the stock cooling system engine gets hotter than the front.
All racers seem to have that basic idea when we modify our cooling system.
My approach is to run the both of the size coolant rails to the firewall where it’s collected in a small header tank that is higher than the radiator. I then run an aluminum tube to the radiator from the bottom of that tank. Connected to the radiator with a short piece of silicone hose.

THE REAL ISSUE IS THE COOLANT ISNT HOT ENOUGH! At full throttle ( most of the race my foot is flat on the floor) so I tape up the radiator to keep temps at least 210 F
I don’t use the Jaguar non- gauge.gauge. Since I’m taking that temp from the header tank it’s as hot as it’s ever going to be.
The boiling point of coolant under pressure is well over 230 degrees. As long as the coolant isn’t boiling it’s doing what it should.
If you look the factory temp gauge is in the front. So the back end of the engine can be boiling while the front is reading OK. ( because of the short circuiting the factory system does).
By taking coolant from the back, that issue is avoided.

 

So my follow on question is "Where can I find details on how to perform the mods?" I was looking for this last week, and found references to "Stage 1, Stage 4 etc." but could not find specific info. I thought I had it in "The Book", and I thought it would be possible to find it elsewhere, but my searches seem to be coming up empty. I plan on stripping a lot down later this year to clean up the top, replace gaskets, plugs, fuel injector hose, wiring, among others and this seems to be a perfect "while I'm in there" chance to do it.

Thanks!

 

What I don't get is why didn't jaguar make the coolant flow biased to the rear of the engine as standard? I mean it wouldn't have been difficult for them to specify smaller outlets in the front coolant rail/engine holes to balance the flow more between all coolant outlets from the block.
Surely they tested this & didn't do it for a reason.

 

Ok so it seems to work. Where can I get the details from for all the stages. Have searched but find references to the Lutz mods but not the mods themselves.

Thanks.

 

Sounds really interesting. Would it be possible for you to share detailed photos.

Thanks.

 

Attached. You have the FI engine (fuel injected).
Stage one is all you need for a road going car. But remember, your guage will read higher after the mod, but the rear of the engine will be cooler!

Jaguar did not do this because it is not necessary in a production car, it IS an improvement, but it is not a necessary one. No need to complicate production and thus make it more expensive if you do not have to. No car has ever been made and launched about which the makers did not know something could be improved! The problem with launching a new car is when to stop developing it and start selling it!

 

Big thanks.

I'm guessing Stage 1 is good enough for normal driving.

 

2 of my V12 race cars have moved on to new owners. I’m building a new one right now and as I do the cooling system I’ll post pictures.

 

Part of the reason the factory was able to get away with the system as is, the volume of water flowing into the engine from the pump is greater than the volume of the front holes forcing some additional coolant towards the back.

As RPM increases though, pressure also increases causing greater and greater short circuiting. Resulting in the rear getting hotter and hotter.

 

Where do you place the thermostats in your cooling system Mguar?

 

I don’t. It’s a race car only taken in on the track once warmed up. If I used it on the street I’d build a thermostat for each bank right below the tank.