I feel like I ended the week on a bit of a tumultuous note with my perhaps overly spicy CD-take, so I’d like to begin this week with something I think we can all universally find uplifting. It’s probably exactly what you’re thinking it is: the peculiar and sort of Rube Goldberg-y remote-operated radiator blind setup on the Renault 4CV!
I’m sure all of us at one time or another have taken a moment of reverie to contemplate the way the Renault 4CV limited airflow into the radiator during the cooler times of the year, to allow for quicker engine warm up and more efficient operation, oh, and also for much more effective cabin heating. Cars of the 1950s didn’t exactly have sophisticated thermal management, so sometimes a solution as crude as a radiator blind was just what was needed.
On some cars, the radiator blind was even cruder – just a simple cover that went over the grille to limit the amount of air that gets into the radiator. You can still buy things like this today, for example this one for a Land Rover:
But on the 1955 Renault 750 (also known as the 4CV), there was a much more sophisticated and, arguably, overcomplicated solution. Let me show you:
Okay, so here’s a nice cutaway of the ’55 750. Pretty good sized trunk on that thing! Okay, focus, JJ. Look in the back there; the 4CV used a water-cooled inline-four engine set just aft of the rear axle, hanging out and giving the car a pretty substantial butt. Just in front of the engine is the radiator, set basically right behind the rear seat and fed air via two small grilles, one one the leading edge of each rear fender.
You can see the little vertical air intake there, just above Ms.Reclina’s foot and above that chrome stone protector on the rear fender.
Okay, let’s get a closer look on the radiator. Computer! Zoom and enhance cutaway, focus on sector 12,5!
Okay, so look at this: there’s the radiator, just above the differential, and in front of that radiator, rising from the bottom, you can see what looks a bit like a window shade. That’s the radiator blind.
The blind is being supported by a thin wire, and if you follow that wire, you can see it leads up into a little tube atop the radiator, then snakes into another set of tubes that seem to disappear up into the C-pillar there.
And where does that all end up? Glad you asked. It ends up here:
The wire emerges above the driver’s side door, connected to what looks like a little crank. As that kid in the picture notes, that’s the radiator blind control!
So, from the driver’s seat, it looks like one can crank that little wire to pull the radiator blind up and down. This is such a hilariously simple and yet also complicated and fussy system, I can’t help but love it. It’s pretty great because it allows you to adjust the volume of cooling air the engine gets while you’re driving, from the comfort of the inside of the car, letting you limit it to get the heat going faster, then open it up as the engine warms up.
I wonder what that little crank felt like to use?
Oh, and you may be wondering why a little kid is showing us this. That’s because in this 1955 brochure the theme was, it seems, just letting a crapload of kids go ham on this little Renault:
I’ve always found the controls and trim in a 4CV to be kind of fragile-feeling, so I wonder if these kids with those hundreds of little probing fingers did any damage to this test car?
Of course, every 4CV I’ve encountered has been a half-century old or more, so perhaps when new things felt a little less spindly? Anyway, I kind of love this way of presenting a car, just flooding the thing with curious kids.
And, back to the remote-operated radiator blind – I know there were other cars with remotely-operated grille shutters (the Jensen 541 comes to mind) but I can’t think of any with such a strangely complicated system like this remotely-operated wire-driven-reverse-windowshade setup on this Renault.
So many good hidden things get revealed by the grubby little hands of kids, right?
Ah. This wasn’t the only French car with an unusual thermal management system. The gas-engined Peugeot 504 had an electromagnetic fan clutch. There was a little wire that ran to a carbonish-looking brush that was in contact with a ring on fan hub. When energized by some thermostatically controlled relay, the electromagnet would engage the rest of the fan, spinning the blades. It was all-or-nothing and there was no failsafe if the brush wore out. The owners’ manual made no mention of it or how to maintain it (although that was pretty simple to figure out).
I assume the orange tubular things coming out of the radiator are the heating ducts, which means the fan pushes air through the radiator instead of pulling air through, as usual.
Sadly, I know very little about Renaults in general, and I’m a lesser man for the fact.
But that 4CV is bona fide adorable, and those old photos, especially with the amber tint (one presumes from old film stocks… you know, how lots of 1970s movies have that warm tint). And those lovely ladies, with curls and skirts and sturdy foundation garments… boy, it must have been a great time to be a young man back then. 😉
Thanks Jason!
Or the sheets of cardboard I often saw on trucks back in the ’80s,
I still see them. And on school buses.
Just what I was thinking. On all vehicles. Not just trucks. I still see this once in awhile in winters. It looked dumb back then and is even dumber today.
Heavy trucks often have actual radiator blinds, usually a lover system like a jalousy window
What stands out for me is how under-square the engine is. 760CCs of torque.
Pretty sure early “stroker” Saabs had a similar arrangement, though with a much simpler operating method.
IIRC, the Volvo PV444/PV544 also had blinds for the radiator that were pulled up with cable or chain via a control of some sort under the dashboard. Not as Rube Goldbergian as the 4CV, tho…
Came here to make this comment as well as the one above it. Volvo and SAAB both offered this feature. It gets cold in Sweden, you see.
“so I wonder if these kids with those hundreds of little probing fingers did any damage to this test car?”
As a father to four kids, the answer is unequivocally yes. Yes they did.
In my experience, they left 40 cheddar Goldfish crackers and an inexplicable footprint on the headliner.
I’m sure there will be a melted crayon found somewhere years later.
I once spent a Friday night prying a petrified McNugget out of the seat track of my Roadmaster. When I finally extracted it, I just sat there thinking “I used to be cool. Girls would call ME to ask if I wanted to go out.”
I’m going to imagine the mechanism was spring loaded, and if the wire snapped you would freak out at the flappity-flap of the shade spinning around deep in the rear of the car.
Air-cooled VWs have a similar setup, but it’s thermostatically controlled. The thermostat sits under cylinders one and two, directly in the path of the cooling air driven by the fan. As it expands or contracts, it operates flaps that determine how much cooling air the engine receives. Some people like to remove them, but they help the engine reach and maintain the correct operating temperature. Removing them also makes the engine take longer to warm up. With the flaps in operation, the heater starts blowing warm air before I even leave the neighborhood.
A Corvair has a similar arrangement! The brass bellows have isopropil alcohol sealed inside, as it heats the alcohol vaporizes expanding the bellows and opening the under engine cooling flaps.
Finally! A Cold Start topic that’s worthy of the title!
The Germans are really good at complexifying things, but the French have made it an art form.
French cars are just fantastic.
Having children mess around with a vehicle was the standard quality assurance test in the day in France.
I believe they called it “Le Test Officiel de Cassage et de Pliage de Merde pour Enfants”. The LTOCPME was not widely recognized outside of the land of the Fleur-de-Lis, except for at AMC in the 60’s.
It’s those same quality standards that lead to AMC and Renault merging in the 80’s. However, the French found that the larger, meatier hands of American children were much more rough than of their own children. That’s why the Renault Alliance was such a mitigated disaster, only the finesse of a 10 year old boy from Nice could adjust the mirrors or tune the radio without breaking anything.
My sincere thanks for the brilliant writing and intriguing ideas. This is the kind of alternate reality that we Autopians deserve, not the shitty actual reality we’re currently getting.
I suppose the test 10 year old kid from Kenosha snapped the mirrors like a twig.
It was terrible, they even gave the parts bins to the kids in the AMC Office Daycare Center and they ended up turning to “plastique” dust. Like a damn croissant put through a food processor.
One would think this would be cause for concern, but the French employees didn’t mind as their kids were too busy helping the Engineering Department with the new Renix fuel system at the time.
While I can’t condone transporting your brood in the frunk, it might be preferable to rooftop binky mobile accommodations.
I’ve lost count of how many kids I’ve encountered that should absolutely be transported in a trunk.
It’s not like they ever could figure out how to make a wagon of the 4CV.
The 928 has an automatic one controlled by the ECU.These shutters are great until they fail closed on a warm day…
Would’ve been simpler to have a couple of those kids hang out the back windows and cover the radiator inlets with their hands.