OK, time for a collective head scratching please people.
I'm currently fighting with Moby Dick over cooling. I want it to run cool, it wants to operate as hot as possible. Before we go to arbitration I thought I'd bounce the situation off the Brains Trust and see what (if anything) I'm doing wrong.
The standard D Special has an engine driven fan that would look at home on a Cessna. This fan operates in a moulded shroud such that all of the air coming through the radiator core passes through the shroud on its way to the egress via the engine.
My bright thought was to replace the engine driven fan with a 12 inch electric fan that fits snugly into the round part of the shroud. I was then able to remove the engine driven beast and gain a few horsepower as well as lose a few decibels of noise. So far so good, however the engine then wanted to run way too hot for my liking. I've got the fan thermo switch set to cycle around the 180F mark which seems to be a preferred running temp.
Driving to Phillip Island last weekend I found that on an average evening the fan was running almost continuously and the temp would rise to around 190F even with the fan running. As soon as I stopped and just ran the fan without the engine running, the temp would drop quite rapidly.
I figured I wasn't getting enough airflow through the radiator, so I removed the ducting from the front. Made no change, and in fact the car ran even hotter all the way home from the Island on the Sunday. Next guess was a lack of coolant flow.
That evening I removed the thermostat and tested it in a saucepan of boiling water. It opened only about 2 or 3 mm so I figured I had found the culprit. On spec I also removed the radiator and had the tanks removed and the core cleaned.
I've put it all back together without the thermostat (ordered but not yet arrived). And guess what? It still runs too bloody hot! I've now restored the mechanical fan and re-installed the front ducting. We'll see how it goes now, but this is annoying.
My basic question is this. How critical is the front ducting for airflow through the radiator at highway speed? I would have thought that with everything clean, and no thermostat, that the temperature whould be well maintained at a lowish level by the airflow alone at 100Kmh. However the fan wanted to run continuously and the temp was still getting too high.
The next plan is to fit two 9 inch fans mounted directly onto the radiator core. (Naturally the one I've already bought is too big to fit flat against the core!) My gut feeling is that these two fans, with the moulded shroud removed, should provide all the cooling a car could ever want, but I have to save up for two new fans first!
Am I missing something really obvious here? (Apart from the statement that Mr Citroen knew the right way so don't change it!)
Any information gratefully received.
Cheers Pottsy (hot under the collar!)
I'm currently fighting with Moby Dick over cooling. I want it to run cool, it wants to operate as hot as possible. Before we go to arbitration I thought I'd bounce the situation off the Brains Trust and see what (if anything) I'm doing wrong.
The standard D Special has an engine driven fan that would look at home on a Cessna. This fan operates in a moulded shroud such that all of the air coming through the radiator core passes through the shroud on its way to the egress via the engine.
My bright thought was to replace the engine driven fan with a 12 inch electric fan that fits snugly into the round part of the shroud. I was then able to remove the engine driven beast and gain a few horsepower as well as lose a few decibels of noise. So far so good, however the engine then wanted to run way too hot for my liking. I've got the fan thermo switch set to cycle around the 180F mark which seems to be a preferred running temp.
Driving to Phillip Island last weekend I found that on an average evening the fan was running almost continuously and the temp would rise to around 190F even with the fan running. As soon as I stopped and just ran the fan without the engine running, the temp would drop quite rapidly.
I figured I wasn't getting enough airflow through the radiator, so I removed the ducting from the front. Made no change, and in fact the car ran even hotter all the way home from the Island on the Sunday. Next guess was a lack of coolant flow.
That evening I removed the thermostat and tested it in a saucepan of boiling water. It opened only about 2 or 3 mm so I figured I had found the culprit. On spec I also removed the radiator and had the tanks removed and the core cleaned.
I've put it all back together without the thermostat (ordered but not yet arrived). And guess what? It still runs too bloody hot! I've now restored the mechanical fan and re-installed the front ducting. We'll see how it goes now, but this is annoying.
My basic question is this. How critical is the front ducting for airflow through the radiator at highway speed? I would have thought that with everything clean, and no thermostat, that the temperature whould be well maintained at a lowish level by the airflow alone at 100Kmh. However the fan wanted to run continuously and the temp was still getting too high.
The next plan is to fit two 9 inch fans mounted directly onto the radiator core. (Naturally the one I've already bought is too big to fit flat against the core!) My gut feeling is that these two fans, with the moulded shroud removed, should provide all the cooling a car could ever want, but I have to save up for two new fans first!
Am I missing something really obvious here? (Apart from the statement that Mr Citroen knew the right way so don't change it!)
Any information gratefully received.
Cheers Pottsy (hot under the collar!)
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