Comment by sidewndr46 | Hacker News Reader

Comment by sidewndr46 | Hacker News Reader

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This doesn't make any sense, because sperm oil was known for its low temperature advantages. Not its high temperature ones.

Even in 1975 the problem cited was corrosion:

https://www.nytimes.com/1975/04/17/archives/transmission-pro...

"The fittings between the cooling unit and the radiator gave no trouble when whale oil was the fluid, but the substitute allowed the fittings to corrode. "

The resulting corrosion allowed mixing of oil and coolant. Causing issues in both, although the transmission is going to be the first to have problems.

I will also point at the idea that the lack of sperm oil caused this is....stupid. The way you avoid this entire problem is by using a device called an oil cooler. It's a separate finned radiator from the coolant radiator. If it leaks you get a little pinhole leak. Then you replace it & topoff the fluid. Automotive manufacturers insist on using combined units because they are being cheap and don't care about the long term practicality of a vehicle. So even if there was some amazing advantage to sperm oil, it neither prevented this specific problem nor did the ban on it cause it.

The plot thickens. Those coolers have been constructed of brass since forever and often still are. IDK if the specific brass alloy has changed. Perhaps the new fluid was slightly corrosive to yellow metals? That's not unheard of but plenty of transmissions have bronze bushings in various places do you'd think they'd create a fluid that was safe for yellow metals.

Edit: It was the solder.

https://www.hemmings.com/stories/2015/03/16/tech-101-automat...

They hint that the whale oil was relevant to the performance of friction modifiers. Friction modifiers are notoriously nasty so it doesn't surprise me that without the whale oil they had to use the "next best thing" which wasn't quite good enough at the margin.

https://washingtoncitypaper.com/article/218915/do-the-japane...

These ^ guys allege to have done some research and stop just short of saying "gm was making excuses for problems they brought on themselves".

There is an interesting assertion in there:

"because when combined with sulfur it made an excellent lubricant,"

Almost anything is a good lubricant when you add sulfur. The reason why sulfur isn't added anymore is environmental reasons. Newer diesel fuel isn't as good of a lubricant as the old fuel was because highway diesel has to be low sulfur now.

So if sperm oil was only a good lubricant when mixed with sulfur, then it's a pretty average lubricant.

Also the article says 5500 transmissions "failed prematurely" 1973-1975. In the US, 5550 transmissions might as well be zero. Even in 1975, most cars were already being sold with automatic transmissions. This whole thing sounds like GM was using sperm oil because it was available and known to work. Then the ban comes in & GM made some poor decisions, then blamed the whole thing on "conservationists".

If only whalers had managed to hunt all whales to extinction in the 19th century GM could have been saved the total embarassment of selling junk cars.

The fact that engines are designed so that coolant and lubricants can mix has always left me a bit suspicious of planned obsolescence.

I think realistically it’s a limitation of the casting process, but it is to me the dumbest part of internal combustion engine design. Point the channels in two different directions on the casting, and only a cracked block should allow them to touch.

but that is unrelated. Automatic transmission fluid isn't circulating through the engine on any vehicle by design that I have seen.

Plenty of vehicles with a standard gearbox just use the engine oil as the transmission lubricant. In motorcycles this is called "unit construction". I've heard of some older Saabs that did this as well.

> The resulting corrosion allowed mixing of oil and coolant.

Why is that unrelated?

because the mixing the article talks about it transmission oil and coolant.

When a passageway cracks in a cylinder head & engine oil becomes "milkshake" that is the mixing of engine oil and coolant. Two separate kinds of oil in different places.

You should watch videos on how hard head gaskets are to design if you want an idea of some of the engineering involved- I think "engineering explained" did one recently on youtube.

What I’m saying is, should we still be building engines that rely on “the” head gasket to keep fluids separate?

An engine cylinder at a minimum must deal with: lubrication, fuel, and gasses. The exhaust manifold deals with half of the gases. I can’t recall if common rail injectors are still technically part of the head (I can find pictures where the CRI system sits on the head, with separate gaskets, but I’m not a mechanic).

With modern manufacturing would we not be better off splitting these tasks up so that only a cracked engine block can mix fluids. Not a torn gasket, not a warped head, not a thrown rod (though rods are going away too).

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