I just discovered something about the A-57...

I just discovered something about the A-57 "multibank" engine from Chrysler. It was first put in the M3A4 Grant/Lees, but far more of that awkward thing were placed in M4A4s for the British Commonwealth forces.

The shortage of radial air-cooled engines forced American production to use a Chrysler (A-57) Multibank engine, an aggregation of the five engines of automobiles, working a common crankshaft through a gearing system. Early in the life of the Multibank engine, it had been placed in the M3A4 Grant/Lee version made for the UK, but only in 109 of 3,352 M3s built by Chrysler’s Detroit Arsenal had them. This was a stop-gap thing so production could continue until the "Sherman" production began in earnest. On the shorter M3A4s the hull (including tracks and chassis) was increased by just over a foot to accommodate the awkward engine. In the larger M4A4 "Sherman", only six inches of extra length were required.

Out of the tens of thousands of Shermans built only a total of 7,449 of the Chrysler engines were made for the M4A4 (dubbed Sherman V by the British), and 109 for the M3s. Both the M3 and M4s generally used radial aircraft engines in the beginning, but there was fast becoming more of a need for aircraft engines than engines for tanks. There were a total of five engine types installed in the Sherman alone, and three different engines in the M3.

There were Guibertson (sp?) diesel aircooled radials in the M3, GM 12 cylinder diesels (two inline 6s coupled together) in both the M3 and M4s, Wright/Continental gas aircooled radials in both, Chrysler A-57s in both, Caterpillar diesel aircooled radials in the M4, and of course the best and most common engine; the Ford GAA V-8s.

For a decent color photo of one of these A-57 beasts, goto:

30 Cylinder Chrysler

By adding up all of the M4 models which were constructed by the various factories in North America between February 1942 and June of 1945 one ends up with the number 48,496. Not quite 50,000.

Chrysler's Detroit Tank Arsenal built and delivered 17,947 (six different M4 models).
GM's Fisher Grand Blanc Arsenal built and delivered 11,358 (five different M4 models).
The Canadian Angus Works built 188 (one model).
Lima Locomotive works built 1,655 (one model).
Ford Motor Company built 1,690 (one model).
Federal Machine and Welding built 540 (one model).
Baldwin Locomotive built 1,245 (two models).
American Locomotive built 2,300 (two different models).
Pressed Steel Car Company built 8,147 (four different models).
Pullman Standard Manufacturing Company built 3,426 (two different models).

We were far from completely "standardized" either, but much more so than our Axis enemy!

 

I love weird multi-bank and multi-cylinder engines, and I'm always looking to up the cylinder count.

Other interesting tank engine arrangements include the M5 Light Tank, with two V-8 engines, each with its own 3-speed auto transmission, driving a common differential. It proved a very reliable system. The Australian Sentinel tank (see my icon) had a similar system, but used three Cadillac V-8s for a total of 24 cylinders.

In the air, the Rolls-Royce Vulture combined two Merlins into an unnatural, and unsuccessful X-24. Far better was the Napier Sabre, an H-24 consisting of two flat-twelves stacked together. Though this engine had some problems in the field, these were due to poor quality control in manufacturing rather than bad design.

The Germans came up with some multibank watercooled air engines, including one of 24 cylinders I believe, but these were unsuccessful. Also unsuccessful was an American postwar design that combined two twin-bank air-cooled radial engines for a total of 28 cylinders and about 4,000 horsepower - there just wasn't enough air to cool the rear cylinder banks.

In modern times, turbines, jets and very large diesels are used for high-power applications. One blast from the past is the Bugatti Veyron, which features a 1,000 horsepower W-16 engine.

Also see http://en.wikipedia.org/wiki/Hyper_engine