Curbside Classic: BMW 524td – An Austrian Stroker Powering America (not a post about the governator)

By
– Posted on April 25, 2018

Three is a series, right (even if it pertains to the 5-series)? So here we go, with my latest installment of  super rare 5-series BMWs or based on 5-series super rare automobiles. Welcome to the stage, E28 524td!

For quite some time now I have been suspecting that some person close to the place where I’m getting my hair cut is really into E28s. Over the past 12 months I have seen parked in the street not only a 528i, but also a 535i and alas, even a 525i. But how could I be prepared for this?

When panic struck the automobile industry in the 1970ies over rising gas prices, this was most true for those manufacturers relying on powerful engines as their core brand value. That’s why a clever crew of BMW engineers took an M20B20 block, beefed up the internals (connecting rods, cylinder heads, pistons, valves, crankshaft)  and increased the stroke from 66 to 81 milimeters. Keeping its 80mm bore,  the M21 almost qualifies as an entry in the 2.5 liter class, coming short barely at 2.443 cubic centimeters (149 cui) of self ignitin‘ displacement. BMW called it the M21D24 (for Diesel, 2.4 liters of displacement), dropped it into an E28 chassis and put the package on a boat to America – not an uncommon practice at the time for German car companies. 

For those whining about the lack of low-end torque in BMWs M20 engines, how is that for a stroker? Almost as good as the gasoline stroker M20B27 in the 525/528e I’d say. Only that didn’t have a turbo.

The M21D24, however, was pumping out a solid force-fed non-intercooled 114 american horses (115 weaker continental European horses) at 4800 rounds per minute and between 155 and 162 lb ft of torque at a lowish 2400 rpm. Numbers like that sound vaguely familiar, malaise-ish even? Well, it’s because they are, or close enough. Besides applications in the E28, E34 and E 30 BMWs, the M21 was briefly offered in the 1984-85 Lincoln Continentals. As the Windsor V8 was recovering some the ponies it lost in the seventies over the course of the 7th generation Continental’s production run, barely 1500 Lincolns with M21s were sold. If would sure be intersting to drive one and make a great entry into the big car tiny engine contest. Anyone ever been behind the wheel of a BMW powered Lincoln and cares to share his or her driving impressions?

But I am getting carried away. In the E28, the M21 was nothing less than the worlds fastest diesel powered car when it entered the market in 1983, topping out at a stellar 112 mph and reaching 62 in 12.9 seconds all the while returning 33 mpg on the super optimistic European consumption cycle (real world fuel economy was around 25 mpg): Not bad for its time and day.

 

 

Even more interesting than this example’s condition is the fact that it is still in existence at all. In Europe, diesels are traditionally bought by those racking up a lot of miles, so most older diesels have died from natural causes. The few still remaining are mostly banned from German cities, with the exemption of cars 30 years and older – an age few diesel live to see.

So it is no surprise that this example seems to be re-imported from Eastern Europe, a place where very handy people and cheap labor keep cars alive that have lived way past their point of being economical – or what do you think it costs to keep a car this old running with labor for BMW mechanics starting at 120 dollars an hour in Germany?

Our little stroker seems to have been brought home from probably Lithuania, at least this is what an internet address imprinted on the windshield suggests.

Very intersting to me are the seats. Certainly not original I would say. Suggesting a taxi duty after market job. But then again, the odo shows barely 70k miles – though I’m sure those handy mechanics from Lithuania could easily have…

In any case they were able to keep a car in great shape that in most places is far from being considered a keeper. This one has termporary plates – who knows where its journey will lead next.

Maybe to Austria? Like that filthy younger brother you don’t want to be seen with in highschool because his dirty pranks jeopardize your candidacy for prom queen, the M21 engine, unlike its gas drinking siblings, was manufactured in Austria at Steyr. Yep, that self same company who has brought us the Mercedes G-Wagen.

It would be one heck of a reunion. Maybe even Mr Schwarzenegger would join such a high class event. By the way, how much torque was Arnie pumping out in 1985? I’m sure he was stronger than the naturally aspirated version of the M21D24. For those awed by the speed and power, this non-turbocharged version was offered from 1985 onwards, boasting all of 86 hp and 112 lb ft of torque. It never made it across the ocean, though.