I need to replace the cooling fan on my 63 OTS. The previous owner has taken the thermostatic switch out of the circuit so the fan is always running whenever the ignition key is on.

I'm planning on leaving it this way, but does anyone see a downside? I don't plan to do any driving during cold weather.

Submitted by SE21-50092 on Mon, 10/10/2011 - 14:01

My 67 E-type (original except has the CoolCat fan) sometimes boils out coolant from the over flow tube after shut down in very hot running conditions and I wonder if there was too much coolant in the surge tank?. Up to now I have avoided this happening by two methods. One (1) leaving the key on and thus the fan running as requested by the temp switch (Otter?) for 5 min. or two (2) keeping the coolant level down (when cold about a 1/3 of the tank but I am afraid this may provide too little margin).

My current remedy to this is wiring the fan circuit (with the Otter in circuit) to always be powered (not in the ignition circuit) and thus the fan runs for awhile after shut down until the Otter switches it off. I do notice that the Otter seems to keep the fan on for a longer period of time (over 5 min depending) with this circuit and am concerned that the battery is taking a beating. The Fan noise is also distracting.

As another remedy, I am considering is putting a discrete/hidden overflow reservoir with the overflow tube at the bottom like the series 2's have to take and give back this overflow after hot shut down.

Your inputs are welcome and appreciated. Steve Chase

Submitted by SE21-50092 on Mon, 10/10/2011 - 13:59

My 67 E-type (original except has the CoolCat fan) sometimes boils out coolant from the over flow tube after shut down in very hot running conditions and I wonder if there was too much coolant in the surge tank?. Up to now I have avoided this happening by two methods. One (1) leaving the key on and thus the fan running as requested by the temp switch (Otter?) for 5 min. or two (2) keeping the coolant level down (when cold about a 1/3 of the tank but I am afraid this may provide too little margin).

My current remedy to this is wiring the fan circuit (with the Otter in circuit) to always be powered (not in the ignition circuit) and thus the fan runs for awhile after shut down until the Otter switches it off. I do notice that the Otter seems to keep the fan on for a longer period of time (over 5 min depending) with this circuit and am concerned that the battery is taking a beating. The Fan noise is also distracting.

As another remedy, I am considering is putting a discrete/hidden overflow reservoir with the overflow tube at the bottom like the series 2's have to take and give back this overflow after hot shut down.

Your inputs are welcome and appreciated. Steve Chase

Submitted by tvtom@sbcglobal.net on Mon, 10/10/2011 - 13:08

I seldom, almost never, drive my '63 FHC in the rain. Therefor I removed , and saved, the washer storage bottle and replaced it with another bottle as an expansion tank. It works quite well.
I have a couple of pictures but, for some reason, I took them as 1 Mb jpg files whereas this list / thread is limited to 200k. If you'd like to see them, give your email address and I'll send them off-list.

I agree that installing an override switch does pose a certain degree of hazard, even with a warning light.

Submitted by SE21-50092 on Mon, 10/10/2011 - 12:36

My 67 E-type (original except has the CoolCat fan) sometimes boils out coolant from the over flow tube after shut down in very hot running conditions and I wonder if there was too much coolant in the surge tank?. Up to now I have avoided this happening by two methods. One (1) leaving the key on and thus the fan running as requested by the temp switch (Otter?) for 5 min. or two (2) keeping the coolant level down (when cold about a 1/3 of the tank but I am afraid this may provide too little margin).

My current remedy to this is wiring the fan circuit (with the Otter in circuit) to always be powered (not in the ignition circuit) and thus the fan runs for awhile after shut down until the Otter switches it off. I do notice that the Otter seems to keep the fan on for a longer period of time (over 5 min depending) with this circuit and am concerned that the battery is taking a beating. The Fan noise is also distracting.

As another remedy, I am considering is putting a discrete/hidden overflow reservoir with the overflow tube at the bottom like the series 2's have to take and give back this overflow after hot shut down.

Your inputs are welcome and appreciated. Steve Chase

Submitted by mfrank@westnet.com on Sun, 10/09/2011 - 22:00

Sorry about that...the JCNA posting system doesn't allow me go backwards.

You can run without a fan, but coolant temperature will be more variable. It may do no harm in the short run, but not the way you want to run. The fan will tend to run for extended periods of time, even at high road speed.

I've done some instrumented airflow tests on a running E-Type, and the results might surprise you. Due to the front bumper, gravel guard and extended nose, airflow attenuates rapidly inside the bonnet, resulting in a loss of 50% of flow. This is part of the reason the fans cycle. The rest of it is that the early E-Type design puts the fan switch at the hot side of the system (directly opposite the thermostat), so it's on a hair trigger . With the S3, Jaguar put the switch on the cool side of the system, which reduces hysteresis, but makes the system less responsive to what's going on in the head.

I'm fully in agreement that people do unnecessary things to these cars. But I'm more concerned about someone putting in a manual switch to turn off the fans (which can cook their motor) than if they install something just for bling.

As for sponsorship, you have CoolCat's contact info. I'm really not looking to discuss business in this forum.

Submitted by SE98-32482CJ on Sun, 10/09/2011 - 21:23

Mike you can simply repeat a previous posting but that does not address anything said. An E type--any model--in good shape in reasonable temps--on the highway does not need any fan--stock or yours. By the way why is Cool Cat Express not a JCNA sponsor? You surely get a lot of business from JCNA members.

Submitted by mfrank@westnet.com on Sun, 10/09/2011 - 21:22

I'm the fellow at CoolCat Express, and for the record, I don't recommend running the fan at all times. The system is designed to cycle, and it should be allowed to work.

However, George is wrong about needing a fan at speed. Even a dead stock E-Type fan setup will cycle on and off at road speeds, that's the way Jaguar designed the system. If the Otter switch signals the Lucas fan that added airflow is needed, then it's needed. And can this happen at any speed, even with a perfectly maintained system. (A running fan adds to airflow at any road speed.) I've yet to see a car of any make or vintage where the fan wasn't running at least occasionally at road speeds. Certainly no E-Type is capable of this.

If you want the fan to run less often, don't install a manual switch. Fix your cooling problem. But if you can find nothing wrong, just relax. The system is designed to cycle.

Submitted by mfrank@westnet.com on Sun, 10/09/2011 - 21:18

I'm the fellow at CoolCat Express, and for the record, I don't recommend running the fan at all times. The system is designed to cycle, and it should be allowed to work.

However, George is wrong about needing a fan at speed. Even a dead stock E-Type fan setup will cycle on and off at road speeds, that's the way Jaguar designed the system. If the Otter switch signals the Lucas fan that added airflow is needed, then it's needed. And can this happen at any speed, even with a perfectly maintained system. (A running fan adds to airflow at any road speed.) I've yet to see a car of any make or vintage where the fan wasn't running at least occasionally at road speeds. Certainly no E-Type is capable of this.

If you want the fan to run less often, don't install a manual switch. Fix your cooling problem. But if you can find nothing wrong, just relax. The system is designed to cycle.

Submitted by SE98-32482CJ on Sun, 10/09/2011 - 21:00

Yes Mike "Cycle" not full on as described. As far as your premise that you need a fan at road speed I guess the 1000 miles I drove from Kansas City to Columbia without a fan in the car (missing) was impossible? Come on--there are too many climates and temps to make a general statement. You know the otter switch works on temp not air flow--if a hot shot of water hits the Otter it will kick the fan on for a second but it is not needed as movement is sufficient. Do not want to question your product here--too many happy customers but you and I know a lot of folks put your product on their cars when the real issue is not the fan! Why do race cars have no fan?

Submitted by mfrank@westnet.com on Sun, 10/09/2011 - 20:48

I'm the fellow at CoolCat Express, and for the record, I don't recommend running the fan at all times. The system is designed to cycle, and it should be allowed to work.

However, George is wrong about needing a fan at speed. Even a dead stock E-Type fan setup will cycle on and off at road speeds, that's the way Jaguar designed the system. If the Otter switch signals the Lucas fan that added airflow is needed, then it's needed. And can this happen at any speed, even with a perfectly maintained system. (A running fan adds to airflow at any road speed.) I've yet to see a car of any make or vintage where the fan wasn't running at least occasionally at road speeds. Certainly no E-Type is capable of this.

If you want the fan to run less often, don't install a manual switch. Fix your cooling problem. But if you can find nothing wrong, just relax. The system is designed to cycle.

Submitted by SE98-32482CJ on Sun, 10/09/2011 - 19:23

Tom the "fellow" at cool cat does not sell stock items. I have no idea what fan he uses or why he would want it to run at speed. Simply put there is no need for ANY fan at speed--that is exactly why Jaguar used this system on the E Type--this of course assumes that the car is in proper tune with a clean cooling system. A lot of folks buy all of these after market items to attempt to overcome simple basic problems that a bit of work would correct.

Submitted by tvtom@sbcglobal.net on Sun, 10/09/2011 - 19:16

I had always thought that the fan, on my '63 FHC, was not needed at highway speeds and, in fact, might actually obstruct air flow at speed. As such I installed an override switch and warning light and turned off the fan while on the highway. An added benefit was the more rapid charging of the battery.

However, the fellow who manufactures the Cool-Cat system stated that the fan actually helped cooling at all speeds.
Tom

Submitted by SE98-32482CJ on Sun, 10/09/2011 - 18:08

You do not need the fan while moving down the road--it will destroy your fan early and it will take longer to warm the engine to operating temps. It is just not a good move.