The car never overheated but then, I never let it get that far. The indicator on the temperature gauge always ran just at or just above the third hash mark on the gauge. Having had a 1976 Spitfire with the conventional radiator and fan setup, the indicator never went over the half way mark. Even though the newer engines ran hotter for emission purposes, the running temperature of this baby seemed just a bit too high for my liking. My quest for a cooler running engine began. First, a little background. The late 1979-1980 Spitfire has an electric fan and a forward tilted radiator, which uses three hoses, one being a vent hose.

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The cooling fan is triggered by a temperature sensor located in the top tank of the radiator. As the coolant warms up it turns the fan on at approximately 202º F and shuts it off at approximately 192º F (depending on the sensor). So when you're idling, your engine temperature is approximately 200 degrees F. all of the time. When I took her out on the road I expected that she would run about the half way mark on the temperature gauge, but instead, she consistently ran near or at the third hash mark.

The sensor.....

The first thing I did was to remove the thermostat and flush out the system and there was no change. I replaced the engine thermostat with a 165º F thermostat and replaced the temperature sending unit and the fan thermostat...all with no change. I took out the radiator and had it re-cored (it did need it) and once again, there was no change in temperature. This last effort with not the slightest bit of change really shocked me. Basically, this baby just wanted to run warm. I decided that since it was not overheating there was a possibility that perhaps the temperature gauge itself was faulty. I substituted a different gauge and the readings were virtually the same. I studied the infamous Lucas electrical system and decided to change the voltage stabilizer, which ...stabilizes the voltage to the fuel and temperature gauges. A negligible change was noted. So, I investigated further. Sometimes you're so close to a situation that you really don't see what's actually there. It's as if you can't see what's on the billboard until you back away from it. I definitely backed away to get a break and attempt to get rid of my frustration.

.One day, sitting around thinking of nothing, it hit me. It was there all of the time - logic kicked in! Since this vehicle (and all others from FM95001 and upwards) did not have a fan that was driven by the engine, but instead was designed with a thermostatically controlled electric fan, the engine would have no choice but to run at the fan thermostat setting when at idle. I did a basic electrical test with a VOM (volt ohm meter), thermometer and water heated to its boiling point of 212º F. My fan thermostat turned the fan on at 202º F. and turned the fan off at 192º F. Therefore, the engine had no choice but to operate at that temperature. It was normal. First problem solved.....there was no problem! I took her out on the road and to my dismay; the engine remained at that temperature even at 55 MPH for a decent period of time. Now that's a problem, especially with a 165º F engine thermostat and all of the work I had done. It felt like I was starting at "square one" again.I went through my entire collection of Spitfire manuals repeatedly and finally found a part that I was missing. An "Air Intake Cowl" part # WKC4224, was not in place. Have I found the culprit?

After hearing from some folks, I ruled out this item as my problem along with the front marker plate (plinth) restricting airflow. Someone suggested that the black rubber bumper impeded the airflow to the radiator. How could it? It was designed to run with all of those parts in place. Another person wrote and told me he had replaced the rubber bumper with a chrome bumper set-up and the running temperature never changed. Actually, air does flow a bit differently in the 1979/1980 Spitfires because of the bumper and tilted radiator. The grille is a part of the black rubber bumper. Therefore, my search continued and just by sheer, absolute dumb luck, I find that two different spoilers were used on USA Spitfires; a pre FM95001 and a post FM95001 series spoiler. So, I went out to my car and sure enough, my 1979 Spitfire had an old pre FM95001 spoiler on it. I break out my microfiche and search for a picture and without a doubt, the spoilers are different, and not only in looks but also in the way air is deflected.

My questions were, "is this the culprit?", "will this solve the problem?" and "where to find one?" At this point, I was beyond frustration and thought everything I was doing or thinking of doing was "reaching" for THE answer. I went hunting and low and behold, found the "correct" spoiler on eBay for a very reasonable price. Comparing the two spoilers showed that a great deal of the airflow to the radiator was indeed restricted with the earlier model. Part of my problem was that the spoiler actually deflected air away from the radiator instead of allowing it to flow to it and through it. My only way to know....road test. Sure enough, at highway speeds, the temperature dropped to the half way mark on the gauge and stayed there until I came to an idle.

I had found the culprit. Simple, simple stuff along with some PO changes had made such a big difference in the operation of this vehicle. Now that I understand the entire situation, I guess I can look for a thermostatic fan sensor with a lower engagement temperature and that would definitely lower the running temperature. I think I'll stick with what I've done so far and see how it goes. That might be another story.
I have to say that after all of the frustration and work I had done, it did pay off. My Spitfire has a cooling system that is functioning the way it was designed to and I can now enjoy driving on summer days with a lot less fear of running this baby hot. I must admit though, I will keep an eye on that temperature gauge!

Over the past 2 years I have been looking for a supplier for the cowl piece (WKC 4224) to complete my cooling "condition". (Fitted after commission #95001 or on the Black Bumper Spitfires) I could not figure out how and where this contraption mounted. People at various Spitfire websites could offer no assistance and yet others said it was not a necessary part. I was recently contacted by a gentleman in Holland who was interested in my cooling situation and through a wonderful two weeks of email conversation, the "light bulb" went on for me. We both went to work, thousands of miles apart, on the cowl piece using our cars and the drawing above to construct, what I feel, is a perfect replacement part. This gentleman, Julian Saul, took the time and effort to draw a flat pattern layout of the cowl, and I must admit, it is superior to mine. When winter rolls around I will probably construct a new one. As for now, I have installed my home-made cowl and have road tested it. Once installed it really makes sense. It looks like a muscle car hood scoop, inverted, and is an integral part of the front spoiler. It forces air directly into the lower section of the radiator. Result: It cools the engine down about 10-20º F at 40-50 MPH. Here is a picture of mine which I made out of 26 gauge galvanized steel and painted black. Julian's is made of aluminum and is currently awaiting a beautiful powder coating. I will post a picture of his cowl when it becomes available. I will include a drawing with basic dimensions, in english, in the near future. To view a drawing of Julian Saul's template in metric dimensions, click here.

Julian Saul has kindly provided pictures of his finished product which he had powder coated to match the frame of his vehicle.

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