mfrank

I actually make aluminum radiators, but not for this particular car. I always recommend a 50/50 mix. These days, there are dozens of very specific formuations, and for the combination of an aluminum radiator and iron block, I prefer Zerex G05, which is worth looking for. Water is better if you like rust and corrosion. I'm not a fan of waterless coolants. The primary consideration for the radiator cap is the thermostat. If you're using a classic bellows thermostat, they you are limited to at MOST a 4 lb cap. The reason is that the bellows is charged with alcohol. The bellows expands when the alcohol vaporizes, and this is dependent on both temperature and pressure. If you increase the pressure, you can actually cause the thermostat to close. If there was a wax thermostat available for your application, then you could probably go to a 7lb cap, but there may be other limitations in the system. So safest to go with a zero or 4lb cap. Another important point that your radiator should NOT be grounded. This may be contrary to advice you'll hear elsewhere, but there's a right way and wrong way to do everything, and sometimes "generally accepted knowledge" is the wrong way. The reason is that coolant will become conductive sooner or later. If you have a bad engine ground, your generator can ground through the coolant to the radiator if the radiator is solidly mounted to the chassis. This can be like running a plasma cutter over your expensive radiator. It may take some effort to suss out some appropriate rubber bushings to isolate the radiator, but it is important. And at the same time, you should make sure your engine grounding strap is in place and clean.

British makers often used AC filtration components, so I would guess AC P127, P172 or P209. If you post dimensions, height, OD and the diameter of the center hole., I might be able to give you a part number.

Two questions, one is, how does a radiator get plugged?, and the second, how does it wear out? The primary culprit in both instances is antifreeze. Traditional Prestone green is a mixture of ethylene glycol and anti-corrosion additives. Specifically, silicate based anticorrosion additives. Silicates do an excellent job of preventing corrosion, because they deposit on bare metal almost instantly. This leaves little opportunity for rust to form. But they are barely soluble. So over time, they tend to fall out of solution, especially if the car isn't in continuous service. Solubility is temperature dependent, so it should come as no surprise that they accumulate in the coolest part of the system...the bottom of the radiator. Over time, they plug the tubes, and it becomes impossible to get a flush solution in to clear them. The radiator wears out by corrosion and mechanical wear. Corrosion will accelerate if glycol coolant is allowed to remain in the car too long. Glycols deteriorate into acidic byproducts under the influence of oxygen and heat, so the longer the coolant remains in service, the more acidic it gets. There are all sorts of old mechanic's methods for identifying worn out coolant, but the simple and scientific way is to use a coolant test strip or litmus paper to determine when it becomes acidic. Or just change it every two years. Mechanical wear accrues from repeated heat/cool cycles. When the coolant gets hot, it expands and pressure rises. When it cools, pressure drops. This pattern of reversing stress causes metal fatigue, and can eventually result in failed seams or burst tubes. When the system acts up, you get wider temperature swings. So prompt attention to bad thermostats and clogged radiators in necessary to prevent much worse problems. The best coolant for your car is always a 50/50 mix. That's true for any car, even if it lives in a garage and never ventures out in the winter. Glycol coolant accomplishes a lot of things: lower suface tension, corrosion resistance, PH balance, lubricity, extended temperature range. Reducing surface tension increases the efficiency of fluid/metal contact, which can reduce localized boiling and pump cavitation. Corrosion resistance speaks for itself. PH balance arises from the coolant containing buffering agents which extend the time the coolant can be used without becoming acidic. And finally, extended temperature range helps prevent boilover in hot climates as well as freezing in cold climates.

Almost all alternators are set up for clockwise rotation. About the only Chevy application that is set up for CCW is Corvair. But you may be mistaken. The fan is designed to pull air from the rear through the alternator and exhaust it through the front. Yes, this is counter to the natural airflow direction. But the reason is that the fan is there to cool the diodes and regulator, which are in the back of the unit. The only front engine cars that I know of set up for reverse rotation are Jaguar E-Type and Honda Prelude. But there are a LOT of aftermarket parts available for Delco alternators, including omnidirectional fans, generally used for marine and aviation applications. There's more on this in my writeup on E-Type swaps: https://www.coolcatcorp.com/faqs/LucasBosch.html

It's the thermostat bypass. When the thermostat is closed, the bypass opens and allows coolant to be pumped around the block, rather than through the radiator. Otherwise coolant flow would stagnate until enough heat reached the thermostat for it to open. The early Buick system is a milestone in thermostat design. I'm writing an E-book on thermostats, you can read about bypass designs here: https://www.coolcatcorp.com/thermostats/Bypass%20Systems.html

Wow. That was quick. Thanks.

Anyone recognize the source for this deco car clock? It's made by Jaeger, and it's a 6 volt movement.

There was only one C4RK. The oddly shaped rear was for aerodynamics, not to be pretty. The aerodynamicist was none other than Wunibald Kamm himself. I believe it ran the fastest lap at Le Mans in 1951, but succumbed to engine trouble and DNF. Cunningham had to make 50 road cars in order to homologate as a manufacturer, and that's the only reason he built the company. It never made money, and for that reason, it was closed by the IRS.

In case you've never seen a Cunningham. This is an exact copy of C4RK made by Panel Beaters of Stratford, CT for the Cunningham family. The original was run through a 3D scanning machine, and the bucks made by CNC. Then the panels were hand beaten.

Thanks, these are helpful. The Packard application is different from the one I posted. It appears to have a true double poppet thermostat, which is the earliest example I've seen. Sylphons were in use for decades before there were automobiles. First as part of mechanisms for measuring temperature and pressure, and later as furnace damper regulators. Your 1917 patent is actually a thermometer, even though he refers to it as a thermostat.

I found my answer. in a 1920 copy of Automitive Engineering. Cadillac was indeed the first application of a water-side bellows thermostat, although it's a bit odd. The thermostat controlled the cold side, and the always-open bypass came through the head by way of a small tube. The same article addresses the slightly later Packard system, which qualifies as the first controlled-bypass thermostat.

I'm writing an article on the history of thermostats. I recently stumbled on an article in the Feb 11, 1915 Automobile that reported on a sylphon water side thermostat that was used by Cadillac that year. The next earliest reference I can find to water side sylphons is in a 1921 white paper. In '21, the idea was clearly novel, and wasn't in common use. It wasn't until 1930 that the relevant patents for the bellows thermostat was filed. So the 1915 reference is very interesting to me, as it would likely be the first application of the concept. I have no access to an example, so I'm hoping that someone out there has either an actual car, a thermostat, or a shop manual and can supply me with some photos and maybe some information as to how this device operated.

I manufacture aluminum radiators for vintage cars, so allow me to give you the inside scoop. First if all, your first consideration is aesthetics vs practicality. With only a handful of exceptions, aftermarket aluminum radiators won’t have anything like the look of the original. If your goal is preservation of a classic, you really should recore your stock radiator. Nothing looks more ridiculous to me than an aluminum radiator in an otherwise original and well preserved old car, and I make these things. OTH, if you are looking for a practical radiator for a driven car, copper is expensive, and more importantly, becoming very hard to find. I can’t think of a single old fashioned rad shop still operating in the Hudson valley. So you will be at the mercy of specialists and a diminishing old stock of parts. Not an unfamiliar situation for the restorer, but not the best for the practical driver. A custom made aluminum radiator will last 20 years or more, but will not be repairable or rebuildable. As for why aluminum works better, it’s not the metal that matters. The secret is fin-tube contact. This is optimized when you have a small number of large tubes. So going from a radiator with three rows of 1/2 tubes to a radiator with a single 1.5 inch tube is actually going to improve heat transfer 15%, regardless of material. Most of my cores have just two rows of 1” tubes. When you enlarge the tube, the walls have to be thicker, and the advantage goes to aluminum because of weight. The rest of it is that there has been a lot of development of fin materials, and modern corrugated fins offer more surface and create more air turbulence than old fashioned accordion pleats. That’s the engineering part, everything else is rumor. Finally a new radiator is cleaner, no matter what it’s made of, and that has to help. Because there are is so much ‘common knowledge’ from the days of copper, there are a lot of bad products out there. Beware of Chinese radiators that advertise four row aluminum cores. These abound, but they are not worth the price, however cheap. Again, fewer, larger tubes is better than more small tubes. And higher fin count also means less air flow, so again, what you remember about copper doesn’t help. Finally, corrosion. Here’s the secret: 50 /50 coolant. Don’t listen to the water cools best crowd, and never mind that you never drive in winter. Antifreeze does more than protect against freezing. I recommend a low silicate antifreeze, like Zerex G05, rather than a dexcool. But whatever you choose, stick to a 50/50 ratio.