CLEVER ENGINE MOUNTS, PART 2
MAGNETO-RHEOLOGICAL technology, as featured in BWI’s clever engine mounts was yesterday’s topic, with a promise today of Part 2’s related memories of one sort or another.
I start with a little etymology: “Rheology” traces from the Greek, wouldn’t you guess; ρεύμα, stream. Rheology is the science dealing with the flow of matter, which is exactly the context in which I first learned of the term.
Attending Worcester Polytech on a United States Steel Corporation scholarship back in the early 1960s, I was also offered work in 1962 as a Summer Technical Associate in its American Steel & Wire Division lab in my native Cleveland.
Unlike some of my other summer gigs (maybe I’ll tell you about selling Fuller Brushes for a single evening), this one was indeed technical, and even reasonably lucrative. Ninety-three cents an hour sticks in my memory; $37.20 a week, gross; $1934 were I to work there year around. And before you scoff at that, check out the CPI Inflation Calculator of the U.S. Bureau of Labor Statistics. In today’s dollar, I was earning $7.59/hour.
What’s even better, the project assigned to me by the lab manager was a non-trivial one: to determine a reproducible means of measuring flow characteristics of a family of certain lubricants.
What did lubricants have to do with wire production? A lot. Steel wire is made by drawing the heated product through finer and finer dies, with fancy lubricants used to facilitate the draw.
I was, in a sense, a Summer Staff Rheologist. No, not really.
I did learn that some materials flow in a Newtonian manner, their stress linearly proportional to strain. For example, a single-grade motor oil is Newtonian; a multi-grade is non-Newtonian.
Some non-Newtonian materials are thixotropic: Their viscosities diminish with duration of the stress. Beach sand is an example. A crab can lie quietly atop the sand or squirm around a bit and sink into it.
Other non-Newtonians are pseudoplastic: Their viscosity depends on the amount of stress: Blood or ketchup, for instance, gets thinner the more intensely stirred.
I confess I don’t remember which lubricant was which, but anyway it was American Steel & Wire’s proprietary information so mum’s the word.
Back when Ferrari owners knew how to drive a manual, we all admired the appearance of the marque’s uniquely gated shifter. Less admirable, particularly among early mid-engine Ferraris, was this shifter’s misbehavior under heavy acceleration.
The engine would react to its ample torque by rotating on its mounts in the opposite direction. This in turn would screw up alignment of the shift linkage.
More often than not, under really enthusiastic acceleration (as in R&T track testing), I’d encounter a blind alley in the first dogleg shift. (With reverse off to the left, this would be the 2-3 shift; with reverse part of the double-H, it would be the 1-2 shift.) Only by pausing a bit (and losing a tick of time) could the shift be accomplished at all.
I bet magneto-rheological engine mounts would have cured this. ds
© Dennis Simanaitis, SimanaitisSays, 2017