In a message dated 10/22/2005 10:47:19 PM Central Standard Time,
> A limiting factor is the surface area of the radiator and its inherent
> efficiency. While the brass tubes are wonderful conductors of heat, the lead
> solder is not, nor is the loss of the central tubes to accommodate the
> starting hand crank that nobody uses. A furnace-brazed aluminum radiator
> small tubes and thin vanes (similar to the core used in the Corvette) would
> be ideal, if expensive. Thicker is not usually better for radiators, and oil
> and transmission coolers are better located away from the radiator instead
> in front of it (or hidden in the tank as in many modern radiators).
There are plenty of alternative radiators and the limitations of the stock
part are well recognized.
> The "pump" can also be be the one that moves air across the radiator. At
> roads speeds or at rest, this would be the fan, and at higher road speeds,
> the forward motion of the vehicle moves air through the radiator (of note,
> the remaining TR3S in LeManns ran with no ill effect with its radiator fan
> removed after fan blade failures in the first two TR3S vehicles; it suffered
> an unrelated oil pump failure) and the design of the front apron is
> at those speeds. The fiberboard radiator duct [MOSS 855-125 (TR3), 855-130
> (TR4)] is an inexpensive and must-have item and might be better fabricated
> from aluminum or PVC sheet for durability if not authenticity.
How true. Fortunately, for me, the small mouth TR3 has the duct as an
integral part of the sheet metal. ;-)
> It also surprises me that no one has mentioned constructing a radiator fan
> shroud. That would certainly be cheaper and more efficient than an electric
> pusher fan and, again, aluminum or PVC sheet - the latter easily heat-shaped
> around a box form - would work well.
Do you mean a shroud that couples the back side of the radiator to the fan so
that the fan air must pass through the radiator rather than around it?
Sounds like a good idea to me. Many cars and trucks with engine driven fans
such an affair. Many cars with electric fans do too.
I think it's a given that the primary weakness in an early TR cooling system
is the amount of air flow. The fans are a compromise of low speed cooling
performance and high RPM HP load. But they are cheap. Clutched fans cost more
and electric fans were not common back then and very expensive.
I guess the real question here is what do you want? In a perfect world you
would have an aluminum radiator with an electric fan. But if you are having a
minor problem with the stock set up, installing a restriction in the bypass is
cheap, easy and quick and it is worth a try. After you reinstall the
radiator shroud, that is.
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