War Hemi: The Story Of The GAA V8 - 1,100ci of aluminum WWII Ford grunt

Yes, this is the

story

of a famous engine: the Ford GAA 18L 1100 cubic inch V8 tank engine. This was a modern Marvel at the time it was produced in the 1940s and it continues to stand the test of time when it comes to Gathering. the attention and star vision of Gearheads who not only love hi

story

but truly appreciate mechanical simplicity and effective engineering. This was an ultimately successful engine built from the failure of another. It was born in circumstances that can only be described as marred by intrigue, and its creation is yet another example of its maker's namesake finding itself on the wrong side of History.

Before we continue, if you're looking for simple stats and a summary of this engine, there are much quicker videos to watch that I'm going to get into. all the good mechanical stuff, but before that happens, there will be a detailed history of the engine and its origins. You have been warned that the history of the GAA engine begins in the late 1930s. The war in Europe is raging. France is wasting away. by The Blitz and Britain is mustering every last ounce of strength, blood, wits and hope to face what appears to be an unstoppable enemy. The country is producing war materiel at the fastest rate it can and the United States can without entering the war. is working with them to supply equipment and improve various industrial sectors of the country to do so since the early 1930s, the Rolls-Royce company has been producing a powerful V12 engine known as the Merlin, assembled by hand with surgical care, they are powerful and reliable. both the Spitfire supermarine and the Hawker hurricane planes trying to take on the German air force that is also devastating the European front that is rapidly approaching Paris, France, during 1939 and 1940 there was only one major flaw with the Merlin.

Britain doesn't have enough of them nor, with the current pace of manufacturers in the country, would they enter an engineer called Maurice Oly, born in England, he was one of the greatest automotive engineers who ever lived from 1912 until the market crash of 1929. he worked for Rolls-Royce and the number of capacities on both sides of the ocean, in particular, he worked as chief engineer at Rolls-Royce's American manufacturing plan in Springfield, Massachusetts, after the market collapsed and Rolls-Royce to close shop in the US Olie went to work for General Motors It was at General Motors where Olie and his team of engineers developed the fundamental principles of automotive suspensions that remain the basis of the cars we drive today in day.

He introduced anti-slip pad testing, stabilizer bars, the roll center concept in-depth analysis of anti-d anti-squat principles, detailed analysis of lateral weight transfer and even worked with companies like Goodye in tire development. Now this guy was a genius, what the hell did he have to do with a Ford tank engine in 1939? His back felt increasingly pressed against the wall. Rollsroyce turned to an old friend, they contacted GM and asked if they could have returned on a wartime leave of absence to help their effort. Olly was assumed to be the perfect guy to work on behalf of Rolls-Royce in the US to get manufacturers of secondary parts and assemblies, perhaps even complete engines in America during the First World War.

He had done much the same for the company, helping it with contractors to help with parts and components for his engine. which they made at the time called The Eagle, the following timeline and information comes from Mor s book called Chassis Design Principles and Analysis. Now there's a section in the book where he talks about the lead-up to World War II and the things that he was. involved in these things not only surround the Merlin but also surround the creation of the GAA Tank Engine and in August 1939, well in Detroit, working for General Motors, Olly receives a cable from Rolls-Royce imploring him for help.

He asks the boss for him and receives. the ability to take leave to assist Rolls-Royce in its war effort from that time until June 1940, he spent all of his time working with potential suppliers to Rolls-Royce, this included establishing agreements for machine tools and dies. An unsuccessful run at Packer to manufacture some small sub-assemblies for Merlin and secure a contract with Wyman Gordon to become a crankshaft supplier for the company not only negotiated the contract for the crankshafts but then went to Republic Steel to secure a contract for the alloy specific information they needed to make the cranks meet the company's specifications, he then managed to get the bow roller bearing company to also be a supplier of Rolls-Royce engines.

It is in June 1940 that the history of GAA emerges under an internationally uncomfortable circumstance. when Rolls-Royce tries to send Oli a complete set of Merlin engine blueprints so he can use them in his manufacturing mission, according to Oli, these documents are intercepted by the US Treasury Department, transferred to the Air Force from the US and kept under surveillance at Rightfield in Ohio, waits an entire week until he is informed that the Merlin blueprints can be picked up during the same week. William nson, whom FDR appointed commissioner of industrial production and production management office approached Ford to build the necessary engines under license from Rolls-Royce Ford Motor Company responded favorably to this idea, so, with Prince in the hand, Olie returned to Detroit and then Ford OE, then went the extra mile and had Rush ship some Merlin components from England to Detroit so the engineers could get their hands on it and see what they would be doing upon arrival. .

Ford engineers swooped on the tracks and, according to oi's account, they were duplicated photographs and photographed at a speed he could hardly believe. Within weeks, parts were beginning to be produced, including the massive crankshafts. It had been leaked to the media that Ford would build these engines and it seemed that the deal was closed, but it was not, even though Ford had accessed all possible existing data and had analyzed the physical parts of the engine, it was not known. had signed any formal contract. Something even worse had been signed. Henry Ford's ability to be on the wrong side of seemingly every major issue of the mid-20th century was about to cause a huge problem.

Henry Ford refused to sign the contract. Newson found out and flew to Detroit. He was embarrassed and insensate and when he got there he was effectively kicked out of Henry Ford's office. The Problem Henry Ford had previously stated that he would have no nonsense about manufacturing anything for American defense and the country's Armed Forces, but he was not at all willing to entertain the idea of ​​building anything that could be used by foreign powers. , even our allies, when they learned of the fact that most of the engines they would produce would return to Britain. Henry Ford refused to comply.

Remember that Packard had previously refused to build small subassemblies. for the engines, but then Newson contacted them in his department and asked if they would be willing to build the entire engine program and they immediately agreed. Ali IM immediately transferred the project there and its success was resounding during the war. Allie saw something very However, it is curious when he was on his way to Ford, as he reports in the quote from his book, an engine design appears and is built in an extremely short time and on a dynamometer it is dimensionally the Merlin but without a single detail Merlin with fuel injected cast

aluminum

crank. block with dry sleeves Etc. end of quote Maurice oi took a look at the first test mule of what would become the GAA and was clearly frustrated because it was strange that Ford could modify the Merlin design and create a working prototype. in all the time it would have taken Rolls-Royce to prototype a handful of individual components in England, so now we have to change the subject.

Remember that at this point we are still talking about airplane engines, the big V12s, the kind that Henry Ford astutely knew there would be a major market for in the coming years and the kind that he assumed could flood the US military aircraft market. ., as long as it could outperform the competition at the time on a national level, that competition was another great V12. the famous Allison v710, but once again in this story Henry Ford played it wrong, we now turn to a document from almost 80 years ago titled Record of Army Ordinances and Development in the World War II History of Ford Tank Engine Development .

The report begins by talking about how the Ford Motor Company recognized a need in the aircraft engine market so they would embark on building their own. Remember that the Merlin was a 60 V12 that displaced 1,650 cubic meters in the report. The States cite a liquid-cooled 60° vertical V12 engine with a displacement of 1,650 cubic meters. It was selected due to past experience with Liberty on Rolls Roy engines. It was paramount that the NB achieve from a high performance standpoint in both horsepower and quantity. Production design studies began in July 1940. End of appointment in mid-August. The plan to take over the domestic military aircraft engine market had been shot out of the sky even though its V12 prototype was already making 1,800 horsepower without breaking a sweat Newson and everyone else had bad news: the Allison V12 engine had been developed and implemented in Many years before Ford had the desire to make an aircraft engine, the Army Air Force had invested millions in parts and spare parts, training mechanics and service personnel, and more, they did not want another V12 engine , no matter how cool or strong it was, but needed a tank engine, the M4 Sherman was now having its own production boom and that was causing its own problems, specifically when it came to power plants.

Until then, most of them were powered by a Continental Air r975 cold-radius engine. others powered by a pair of flywheel-coupled Detroit 671 diesel engines, and yet a smaller number were powered by Chrysler's incredible 30-cylinder multibank engine, which was a collection of five six-cylinder power plants in line mounted in a sprocket configuration, despite these options, none of them were fantastic because the Army needed more and this big Ford engine with a few changes could fit the bill and boy did it do, just inspecting the engine bay of the existing medium duty tank. Ford engineers suggested that by cutting the length and using eight of the 12 cylinders of the already designed and partially developed aircraft engine, it would be possible to produce in a reasonably short period of time an engine that would meet the plant's necessary requirements. of power and that it would fit into the existing room with some slide modifications, the report then lists a host of requirements, such as the need to be able to survive at least 600 hours without an overhaul, have the power to pull up to 60% of the weight of the tank, allow adequate cooling in extreme conditions and operate in a wide power band such as To minimize gear changes made by the driver's tongue and Chek, the report goes on to cite in the absence of this valuable knowledge that the Ford Company ultimately acquired the hard way and proceeded on September 15, 1941 with the designs and details of a proposed engine that he had manufactured. assembled and placed on a test bench on January 14, 1942 over a period of 5 months, at this time GAA was officially born and the birth of Well was undoubtedly one of the strangest processes in Ford history.

The end result was one of the most incredible engines of its age and, for my money, the GAA is one of the best V8 engines in the history of internal combustion engines. Ford did not copy the Merlin. There were some similarities in design, but mechanically the engines were very, very different and we'll get into them all. That's in a minute, but what made the GAA so amazing in the 1940s and even today, let's start to explain that from the bottom up the engine used a cast

aluminum

block with dry steel liners and had aluminum cylinder heads. with

hemi

spherical style combustion chambers in the center. spark plug mounted, dual overhead camshafts and four valves per cylinder, the intake valves measured 2.12 inches and the exhaust valves measured 1.9 inches or 54 and 48 mm respectively and remember there were two of each, the Exhaust manifolds were not huge lumps of cast IR, but were made from stainless steel halves that were welded together to make the finished parts, this was a huge weight saving at 1100 cubic inches or 18 liters.

It is the largest production v8 engine of all time. The diameter was 5.4inches or 137 mm. The stroke was 6 inches or 152 mm the compression ratio was 7 1/2 to 1 and the entire engine weighed 1470 lb the alloy construction was originally intended for use in aircraft where weight was always a concern the Rated engine power was 500 to 2600 RPM and maximum torque was 1100 ft-lbs, it generated over 1,000 ft-lbs of PBS from just above idle throughout its entire rev range. Reports indicate that the engine could be revved to almost 3800 RPM before valve float began, if you are wondering why the V8 made 500 horsepower while the V12 made 1800 horsepower on the dyno, the reason is simple boost, the big V12 was supercharged, in the case of this engine the naturally aspirated induction was via carburetors, either the bendex Stromberg na y5g in the GAA version or the bendex Stromberg hd5 or hh5 in the The G version had a lower vertical profile to fit different pieces of equipment inside this engine there was a 180° flat nitrided cast crankshaft the connecting rods were forged ibeam style units which were shot peened after being forged and I machined the engine.

Cast aluminum pistons. Those pistons were a five-ring design that had a chrome top ring and used a full-floating style wrist pin. Interestingly, no chains were used to drive anything in this engine. A beautiful and robust gear series. and the shafts were used to drive everything from the oil pump to the magnetos and even the camshafts themselves. Another fun fact is that the first version of this engine used a series of angled corset-style main bolts to mount the main caps down creating a large clamping force, which was fine for aircraft applications where no motion was at stake. of the crankshaft, the problem was in a tank with a clutch that activated abruptly most of the time, the crank moved back and forth during the tests, causing wear of the main bearing.

This design was quickly discarded for a more traditional four-bolt main cap, and at that time those two were changed to a two-bolt style main. which R deemed and proved to be strong enough to do the job, lastly the additional step of thickening the block's main webs was taken to prevent any possibility of crankshaft movement in those fora. Like all new designs, GAA had its fair share of teething problems. For example, spark plug wires that were caught in valve covers suffered failure when the temperature there reached over 300° and the wire insulation failed. It was discovered that an oil cooler was necessary to control temperatures.

Exhaust valve failures were also a problem with early engines until the exhaust valves were upgraded to sodium stellite field units and solved that problem completely. Ford worked hand in hand with military testers and effectively modified the engines on the fly as these problems were discovered and truly what can only be described as hellish. Durability testing done by the military, for example, one of the tests was running one of the motors for 100 hours straight at full load and RPM on a regular Eddie style Dyno. Other test records are just as impressive with engines running through a series of tests for sometimes almost 500 hours without failure as designs were updated and improved.

It should also be mentioned here that in 1944 the military wanted the V12 engine to be effectively the one that started this whole process and wanted it to be put into production for use in even larger and heavier tanks. This engine was known as the GAC, the GAC shared the same technical specifications as the V8, except for the addition of four cylinders, so if you've been hearing this all the time thinking that Ford definitely ripped off the Rolls-Royce Merlin, it's time They share some of the reasons why they didn't totally copy Merlin, but they certainly took inspiration from it.

If Ford did anything, Ford looked at Merlin, which means they applied all their extensive knowledge in mass production, manufacturing foundry technology and everything else acquired when becoming a singular industrial colossus, let's start from the bottom with the crank. All Merlin engines used a forged crankshaft and in his opinion it was the only way an engine of this size and power level could become reliable. Ford had been using nitride-hardened cast iron. cranks for many years at this point and they believed in that technology so they stuck with it and of course it worked in the GAA. One of the biggest differences in the engine came with the connecting rods.

The GAA used traditional single connecting rods mounted side by side. crankshaft pins, the Merlin used a fork-and-leaf style connecting rod, making the GAC the 12-cylinder version of the GAA longer than the Merlin because the cylinders must be offset to correspond with the connecting rods, and a fork-style connecting rod engine and leaf. the cylinders should be completely parallel, in my opinion, why was this done for the GAA? Simplicity, the front blade rod requires more work and time to produce to return to full Fordization of the engine, the GAA was a constant study in simplicity of design and assembly.

Next we go to the engine block, the Merlin block was made of several pieces, there was a crankcase and then there were actual cylinder blocks that slid down on long bolts and then sandwiched over themselves when the heads were installed. Ford Block was a single piece of aluminum casting and the company was one of the few on the planet that could pull off something this size in the late '30s and early '40s. The monolock casting technology developed by Charles Sorenson in the creation of the 1932 Ford flathead V8. Now about a decade or more old, the company had perfected it and that's why it was one of the few places on the planet that could produce something of this magnitude as a single piece.

The Merlin was an overhead cam engine, but it was a single overhead engine. Camshaft design that used rocker arms to operate the four valves per cylinder. The GAA was a double overhead camshaft engine that eliminated rocker arms entirely and used cam followers or hubs to drive the valves. This again greatly simplified the valve train and eliminated a lot of potential failure points with the rocker arms, approximately 28 8,000 GAA engines were now produced in a couple of variants, in contrast Packard alone made 55,000 Merlins and over the course of the entire operation of the Merlin engine, all variants included more than 168,000 were manufactured, the GAA was and May always be the largest aluminum V8 engine ever mass produced.

The best part is that it was as successful as Ford engineers believed it could be in V8 form and, to a much lesser degree, in V12 form. Furthermore, he never powered airplanes, it was his preferred engine. of the M4 Sherman tank cruiser and larger equipment during the war was easy to maintain made possibly the best power without a doubt when you take into account the weight and did its job with a plum around the world in many different environments the aircraft engine powered by 1800 horsepower it was one hell of a powerful naturally aspirated power plant by the heaviest iron the Allies had in World War II, sacrificing huge amounts of horsepower for tenacious reliability and a simple but classy if you're interested in seeing and hearing one of these beastly engines running out of an old tank.

I can recommend that you look at the tractors. There aren't many, but tractors sometimes employ the GAA engine and occasionally in multiples. Why with Boost these things can produce up to 2000 horsepower, now sometimes that results in massive failures. but many times it results in glorious noise, you can even find examples of people trading these things for muscle cars and Hot Rods for a max, while Factor that's the story of the Ford GAA, the twin overhead cam War Hemi born from a failed bet. to enter the controversial industry of World War II military aviation thanks for watching, like and subscribe for more automotive and Gearhead historical content.