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 Paul Bertorelli

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How Dodge Built Bomber Engines

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November 29, 2020

 Sjekk glimrende video her: https://tinyurl.com/y3hp538r

I have a sort of personal, intimate  relationship with the B-29 and the engines that powered them, the Wright R-3350s depicted in this week’s video. It’s one of those classic wartime promo films produced in the hundreds, but this one is from the Dodge motor company’s PR department. It’s one of the most amazing films of this type I’ve ever seen and well worth the 16 minutes. It shows what we used to be capable of.

More on my story in a moment.

After Pearl Harbor, the War Production Board enlisted thousands of U.S. companies for defense work. Maytag made aircraft parts, Ford made B-24s, Lionel switched from toy trains to military compasses, Henry Kaiser from dams to victory ships. When the government built its own engine factory outside of Chicago, it picked Dodge to run it and apparently made the right choice.

The plant broke ground in June 1942, seven months after Pearl Harbor. Working around the clock, the factory started limited production in spring of 1943, almost two years after the Air Corps had ordered an initial 250 B-29s. Wright developed the R-3350 almost begrudgingly. It had poured resources into a 42-cylinder, seven bank engine called the Tornado and when the war erupted, it switched belatedly to development on the R-3350, a 2200-HP engine that married two nine-cylinder radials with a common crankshaft. The so-called Duplex-Cyclone was nobody’s idea of a great aircraft engine, at least initially.

It suffered from underdevelopment. By the time B-29s were ready for volume production, the engine had cooling problems that persisted through testing and into combat in the Pacific in 1945. It had a nasty habit of swallowing valves, cracking exhausts, leaking fuel and catching fire. On combat missions, according to official Air Force reports, B-29s were limited to 20 minutes of ground time before taking off. Many returned to base before reaching Japan and crashes with the loss of all aboard were not infrequent. Accidents claimed about twice as many B-29s as the Japanese did.

But Dodge charged ahead at the Chicago plant. Working around the clock, the plant exceeded its initial target of 1600 engines per month, all the while making engineering changes that fixed flaws major and minor on the fly. In all, Dodge made more than 6000 changes and improvements in the R-3350. Its TBO eventually doubled from 200 to 400 hours, but operational records suggest the engines were just replaced, the runouts tossed into the prodigious scrap piles on the Pacific island B-29 bases.

Even by 1940s standards, Dodge Chicago was unusually vertically integrated. Some 5000 subcontractors and vendors were involved, but the plant did its own magnesium casting—quite an art in those days—and had a high-volume forging line for cylinders, of which it made more than 300,000.

Late in the war, to solve fire problems related to poor mixture distribution, the R-3350 was equipped with direct fuel injection, something we think of as a new-age engine appliance. Unlike early fuel injection, which squirted a fuel charge into the intake manifold, direct fuel injection puts it directly into the cylinder under pressure, improving mixture distribution and fuel economy. Although the 3350 got better with age, it never matched the reliability of stalwarts like the Wright R-1820 used in the B-17 or the Pratt R-1830 in the C-47.

As was true of most wartime production, the factories achieved astonishing economies as volume increased. Dodge-Chicago built 18,413 engines for 3628 B-29s, the lion’s share. Unit cost dropped from $25,314 plus a $1519 fee in 1942 to $11,537 plus a $580 fee later in the war. The fuel-injected version cost $12,954. In today’s dollars, that’s about $173,000. I suspect the operators of Fifi and Doc would consider that a bargain.

The R-3350 lived on after the war. With power recovery turbines fitted, it delivered good fuel economy in the famed Lockheed Constellation. But pretty as it was, the Constellation was not a commercial success against Douglas’s DC-7, according to “Howard Hughes Airline: An Informal History of TWA,” by Robert Serling. The engine flew well into the jet age in Vietnam in the Douglas A-1 Skyraider.

That was the second time I encountered the R-3350, albeit it a distance. The first was up close and greasy. During my high school days, I had a short-term job scrapping B-29s. We lived in a town called Havre de Grace, Maryland, which was adjacent to the Army’s Aberdeen Proving Grounds. That’s where they test things that go boom and a number of war-weary B-29s had been flown in for ground fire survivability tests. Thus shredded and perforated, they were put out to bid for salvage.

An Arizona company showed up, set up a salvage yard by a railroad siding and hired local help for labor. And there I tore asunder what Dodge Chicago had built. I’m not sure what the market for those engines was. This was 1966 or 1967, I guess. The company had us strip all the accessories from the R-3350—the mags the size of bread boxes, generators and starters and all kinds of miscellaneous pumps and valves. We filled barrels with the stuff.

This was my first experience with aviation-grade hardware and I learned all about safety wiring, castle nuts, banjo bolts and fire sleeve by taking it all apart. This was not necessarily easy with my shade-tree mechanic tool kit, but we got it done. It probably reinforced my urge to become a pilot. I also learned that if you use a cutting torch around magnesium, you’ll start a fire you can’t put out.

What I remember most vividly was the smell. We would shove the 2700-pound engines around with a huge forklift to get at the various parts, spilling oil into a disgusting black slurry that smelled like nothing I’d ever encountered before or since. We must have had both carbureted and fuel-injected versions for one day, someone got the idea of hoisting one of the engines off the ground, dumping some gas into the intake throat and cranking the starter with a pair of forklift batteries in series. It didn’t start, but it belched fireballs and some smoke in a satisfying tribute to Bendix Scintilla, or whoever made the mags.

I don’t remember how many airplanes we scrapped, but we did fill nearly two railroad gondola cars with engine cores and parts. It could have been a half dozen or more airplanes. There were some others in the mix, including B-17s and a few fighters. As for the aluminum parts, we chopped up the fuselages and wings with a big crane-mounted guillotine. I crawled through the B-29’s famous bomb bay tunnel a few times. Yes, it’s claustrophobia inducing.  

We pawed through the wreckage removing steel hardware and the rest of it was fed into a huge gas-fired field smelter. A third of a wing section could fit into it and flowing out the bottom into standard ingots was the best aluminum Uncle Sam could buy in 1944.

It was a sad end to the most expensive program of World War II. The Manhattan Project cost $2 billion 1944 dollars, the B-29 program a third more at $3 billion, for an airplane with a barely more than a yearlong combat career.

Equally sad was the sudden death of Dodge Chicago. VJ Day was announced at 6 p.m. on Aug. 14, 1945. A half-hour later, the plant was dark, the foundry cooling and the forges silent. The workers were gone. When I became a newspaper reporter in the mid-1970s, I met a former B-29 pilot named Bud Pittman. At the time, he owned a grocery store and was mayor of the small town of Hancock, Maryland.   

At the same time Dodge Chicago was wrapping up, he was taxiing a Superfort for a training mission in Nebraska. The tower called and instructed them to return to parking. The war was over. Bud’s final act as a pilot might very well have been switching off the eight magnetos I would later toss into the parts barrels.