getting HOT HOT HOT

[discopotato03]

Yes I remember the flex fans but not sure if they were ever a huge success .

Yes I think the L is a bit unique in that is has a radiator size and shape that's very different to just about anything else out there .
Before I bought a Koyo std one I spent considerable time with the people at Southern Suburbs radiators going through their sizable collection of cattledogs looking for something better with the same approximate dimensions . Really the problem as I see it is that the nose of the L doesn't have a real lot of room in the vertical plane meaning not a lot of height .
A radiator that isn't tall tends to limit the diameter of the fans you can place near it though offset shrouds can help to a degree .

So what you end up with in a std L is a reasonably long not very tall radiator with horizontal or cross flow tubes .
I reckon the water pump fan is a good idea because it pretty much looks after itself , only failings can be the hub or the belt .
AC L's have the electric fan on the drivers side of the radiator so when its running it will pull some of the heat out of the tubes on the drivers side of the core and the water then gets to run past the airflow from the mechanically driven fan on the passengers side of the core . Two bites at the cherry .
The performance of the fans will differ and partly due to how fast they turn . Obviously at idle the mechanical one is slowest so pulls less air than at other times . Had it been electric it could fun flat out regardless of engine speed .
This is not to say I think elec only fans are the go , more just a look at real world conditions .

Now again one of my opinions , others will differ .
Davis Craig say that their fans push more air than they can pull for a given size and I think they quote CFM as well .
IMO a vehicle at low speeds doesn't get much environmentally forced airflow into the radiator so having the "curtain area" of an elec fans motor in front of the radiator may not be much of a disadvantage .
My experience is that an engine and cooling system that functions reasonably well doesn't have a cooling problem at any speed much over say 40 -50 km/h . In these circumstances the theory is that there is enough velocity of air through the core to stop things cooking .
It won't be the case if half the rad tubes are blocked or the water pump impeller has half corroded away . It won't be the case if the engine runs too lean or has ignition timing up the wall for whatever reason . Sometimes its the silly things that make engines overheat - like say a worn throttle shaft letting more air into an old carby than the metered fuel allows for .
Old engines can have lots of blow by and recycling the hot oily crank case gasses through the inlet system isn't really a bonus . Oil vapour reduces effective fuel octane so you can see where someone might retard the timing of a pinging engine and have the retarded timing add to the overheating woes .
Actually I'd like to know if anyone here had or knew of L Series cars when they were fresh and young , I don't recall them being noted for cooling problems but then again I didn't have any particular interest in them at that stage either .

Anyhow back to the fans , my next plan if I couldn't get enough air through my radiator was to put as large a diameter electric fan in front of the radiator as it's height would allow . From memory L's have a vertical strengthening gadget in front of the middle of the radiator but it unbolts and I wouldn't think making one that cleared an elec fan would be too difficult .
I reckon I'd fit it to the drivers side because the AC fan is smaller and also water from the engines top outlet feeds this side so will be initially higher in temperature as it flows into the tubes .

I am still interested in oil cooling but it could be tricky to fit the sandwich adapter in before the filter and miss my fabbed headers tubes .

Anyhow I'd be looking for engine probs as well as radiator ones , old carbys are a pain . Open the throttle quadrant by hand and wriggle the shaft about if possible . If you can feel movement it will almost certainly be leaking unmetered air in and probably causing a few drivability probs through lean running .

Just a few thoughts , cheers A .

[steptoe]

Was looking a little closer at at 04 Mazda 3, 2 litre. It has one electric fan in the pull through side and has quite an extreme lot of shrouding, not big roundish and flowing like but just compact and flat, not far off the radiator itself all the way to the fan blades. This engine is of the newer design where manufacturers have positioned the hot exhaust side to the firewall leaving inlet on the radiator side. Must be an advantage when cooling water when exhaust heat is nowhere near