re: 4 row radiators

[Matt Haas <mhaas@xxxxxxx>]

Eddie,

The part of what a thermostat does is to regulate the flow of coolant 
through an engine by offering a restriction to the flow which gives the 
coolant a chance to pick up heat from the engine. Even though your 
temperature gauge reads lower without a thermostat, your engines could 
still be overheating and you'd never know it because the coolant never has 
a chance to pick up the heat. If you don't feel the need for a thermostat, 
you should at least put a restrictor plate in place (these are sold for 
racing applications but you can probably take the guts out of an old 
thermostat without too much trouble to make your own) so you give your 
cooling system a chance to do its job. The factory thermostat used in late 
60's AMC's was 195 degrees and in slow moving traffic in a hot climate, I 
wouldn't see low 200 degree temperatures as excessive (in fact, many newer 
cars have 210 degree or higher thermostats in them from the factory).

Usually, when cars overheat, it's because something is wrong with the 
engine or the cooling system. Sometimes, there are also design flaws that 
cause overheating, early flat head Fords and V-12 Lincolns are two examples 
but those if there were problems like these on cars as old as our AMC's, 
I'm sure they'd be well known by now. Things like the timing being off or a 
lean fuel mixture (perhaps caused by a vacuum leak) or excessively 
restrictive exhaust (like from a bat catalytic converter or mushed exhaust 
pipes) will cause the engine to run hot. Engines that have been bored over 
(especially if the overbore is near the limits for the block) will also 
tend to run hotter as will engines that have had lots of performance 
goodies added to them (especially if the exhaust is ignored).

Servicing cooling systems (radiator boiled out, recored, or replaced as 
needed, new belts and hoses, new thermostat, new radiator cap) is usually 
one of the first things I do to the older cars I've have since cooling 
systems tend to be ignored. Adding tap water to them will result in mineral 
deposit build up which will plug up the radiator (and the heater core). Old 
coolant leads to rust and in engines with aluminum stuff in the cooling 
system (including the blocks and heads), will cause damage to the aluminium 
parts due to electrolysis. Granted, Cincinnati doesn't get anywhere near as 
hot as Houston but the only cars I've had with hot running engines are 
those that have had a problem with either the engine or cooling system.

To the best of my knowledge, electric fans do not have any advantage over 
mechanical fans (as far as cooling ability goes) with a proper shroud (they 
do have a fuel efficiency advantage and can solve packaging problems, 
particularly in a car with a transverse mounted engine). I'm not sure what 
the shrouds looked like on other AMC's but the one I have here for a six 
cylinder American does not look like an efficient design. The sides are 
straight (which would cause it to only draw air over a small area of the 
radiator) and it has large gaps between the fan and the edge which also 
cuts down on efficiency. I've never seen it installed so I don't know if 
this is a problem or not, but the position of the fan blades in relation to 
the shroud is also very important to efficiency.

Matt

At 01:54 PM 9/11/2005 -0500, you wrote:
> Not that it means anything but have used 4 row radiators, and also run 
> most, if not all, of my cars without a thermostat. Also run most of them 
> with electric fans, you can get them (the fans) off Hyundais at area pick 
> a parts for about $3-$5 each, and takes two to mount on any AMC sized 
> radiator. Stuck in traffic, these can easily drop the temp to about 
> 160-170 degrees. Before the little fans, larger radiator, and thermostat, 
> if you got stuck in traffic, the temp could easily hit 230 degrees, and 
> overflow, especially on my V8s; and a few times car would die and push off 
> to side of highway, not fun on I-10 with 240,000 cars behind you. After 
> letting it cool down, putting in some more water, crank right up. As for 
> the thermostats, it's just something I started doing in the late 70s/early 
> 80s and still do. Rarely do we need them in Houston, as it don't get that 
> cold; although it did snow last Christmas Eve for the first time in 
> Houston's recorded history. I've been told that (above) this can warp the 
> #1(?) cylinder but have yet to see any evidence of it, even on my 68 Rebel 
> convertible with 127,000 miles or my 82 Eagle with 210,000 miles. Chances 
> are your results will vary wildly. I also run all my cars with straight 
> anti freeze, no water, and have for decades, and no problems. And all my 
> cars are driven daily; including the Rebel, Ambassador, 3 Eagles.
> Eddie Stakes'
> Planet Houston AMX
> 713.464.8825
> eddiestakes@xxxxxxxxxxxxxxxxxxxx
> www.planethoustonamx.com

mhaas@xxxxxxx
Cincinnati, OH
http://www.mattsoldcars.com
1967 Rambler American wagon
1968 Rambler American sedan
===============================================================
According to a February survey of Internet holdouts released by
UCLA's Center for Communication Policy, people cite
not having a computer as the No. 1 reason they won't go online.