How the Big Three Geared Up for WWII

Monday is Memorial Day.  And while most of us will spend it watching new episodes of Arrested Development, Fast and Furious 6, and fireworks, hopefully we’ll do so as a celebration of those who gave everything so we could enjoy our burgers.  But while many served and continue to serve overseas, others served at home, designing and building victory machines.  Here’s a little of how Ford, GM, and Chrysler played their part during World War II.

Every day we charge our Facebook page with a new Car of the Day, featuring some great automotive art and a few facts.  While searching for yesterday’s entry, we discovered that though Chrysler has been branding their cars with HEMI badges for ages, the first Mopar hemi wasn’t developed for a car at all, though we wouldn’t mind seeing a ‘Cuda swap with it.


Chrysler began development of the XIV-2220 way back in 1940, proposing a V16 engine displacing 2,219 cubic inches, not cubic centimeters.  That’s 36.36 liters, just a pinch over 5 426 Elephants.  This also meant a very long crankshaft, and crankshaft whip at the prop, so engineers solved this problem by placing the output shaft in the middle of the engine, between two V8 banks.  With the added turbocharger and supercharger, it produced 2500 hp.

By 1945, Chrysler was testing their big V16 in the P47 Thunderbolt.  Production was ready, and while we would have loved to learn that the IV-2220 had seen service, we’re glad to hear why it didn’t – the war ended.  Thankfully, the Hemi would return later for civilian use.

Nor was this the Pentastar’s only contribution.  Chrysler worked closely with Continental to develop the AV1790 Hemi V12 for the M47 Patton Tank, which served in Korea and Vietnam.  Over 9,000 M47s were built.  The AV1790 (yes, cubic inches again), in supercharged form, produced 765 hp and 1670 lb-ft of torque.  An AV1790 later wound up in Jay Leno’s Blastolene Special Tank Car.

Speaking of tanks and airplanes, Ford’s own WWII tank engine started as a mill for fighter jets.  Ford saw the war coming and preemptively started development of a V12.  But Navy brass had decided to only use radial engines in their aircraft, and Ford was left all dressed up with nowhere to go.

As plans to invade Europe and Africa solidified, however, orders for M4 Sherman tanks started rolling in, and Ford, probably literally, sawed 4 cylinders off their V12 and plugged it in as the GAA V8.  Yes, at 1,100 cid, it was still massive.  The GAA could produce 450 hp, enough to get the 30 ton monster up to 30 mph.  The Sherman tank was crucial to the African and European theaters, as it could outrun and outgun the German Panzer II and III.  And though it was no match for German Tiger tanks, because it could be produced so quickly, and because it was so reliable, many infantry divisions were given their own Sherman units, which sped the advance into Europe.

But GM wasn’t about to be left out of the tank building fun.  In 1941, military strategists decided that “tank destroyers” were needed to quickly dispatch any German tanks that might manage to punch through allied lines.  This meant less armor and a 76mm gun, but it also meant more speed.  So they ordered the M18 Hellcat, which used a supercharged 450 hp Continental 9-cyl radial engine to reach speeds of up to 60 mph on the road (though Hellcat veterans have reported tweaking them up to around 70).  While Sherman tanks used a 5-speed manual transmission, GM godfather Harley Earl and his team, who designed the whole tank, opted for an automatic in the Hellcat, since GM had been successfully using their Hydra-Matic torque-converted transmission since the 1940 Oldsmobile.  Buick plants assembled the Hellcats, while Oldsmobile assembled the cannons.

In the Pacific theater, many Hellcats were loaned to the Chinese for use against the Japanese in Burma and proved instrumental in defending the region.  In Africa and Europe, Hellcats were attached to infantry units.  While their speed and firepower proved effective in outflanking German units, by the end of the war, they’d done their job so effectively, few German tanks remained.  A Hellcat’s role transitioned largely into that of a mobile artillery unity, hastening the arrival of VE Day.

GM’s torque-converter automatics became extremely successful, and after the war Buick used the tagline: “Battle-Tested.”

What are your favorite Detroit-developed machines from the WWII era?

2 Replies to “How the Big Three Geared Up for WWII”

  1. What the H is a torque converter Hydramatic. I can find no reference to any hydramatic fronted by a torque converter. My personal belief is a torque converter would have torn those “problematics” to pieces. ( I started driving – legally – in 1950, and worked on cars before that). I have seen some references to tanks using only a Buick built torque converter without a gear box. Does anyone know the real situation here? I am very far along in writing a novel about the post war car business, and have tried to reference some early workings on transmissions. Dynaflow was, of course, significant in the ongoing auto trans development process.

    1. Hi Dean,

      That’s likely just a mistake on my part. I’m afraid it’s been so long since I’ve written this that I’ve lost track of my sources. Apologies. Your book sounds awesome, though! Be sure to let us know when it’s finished, and good luck with it!

      -Andy

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