21 replies to this topic

[Bob Riebe]

https://www.enginela...the-gaa-engine/

 

[GreenMachine]

When I see 'displacement = 1100', I am thinking ccs ...  

[Magoo]

Not to nitpick but the Ford GAA was never a Merlin copy. It was DOHC with bucket followers. The Merlin was SOHC, finger followers, and fork-and-blade rods. 

 

The Ford was also designed from the start for high-volume production. The US military had little interest in liquid-cooled inline aircraft engines but did have a desperate need for engines to power the Sherman M4 tank. So Ford was asked to make the V12 a V8. Hence the 60 degree bank angle.  

 

 

https://www.macsmoto...cubic-inch-gaa/

[Bob Riebe]

Not to nitpick but the Ford GAA was never a Merlin copy. It was DOHC with bucket followers. The Merlin was SOHC, finger followers, and fork-and-blade rods. 

 

The Ford was also designed from the start for high-volume production. The US military had little interest in liquid-cooled inline aircraft engines but did have a desperate need for engines to power the Sherman M4 tank. So Ford was asked to make the V12 a V8. Hence the 60 degree bank angle.  

 

 

https://www.macsmoto...cubic-inch-gaa/

I thought the part about being copy of the Merlin was wrong.

I used the wonderful search engine on this site to see if I had not posted some thing about the GAA beore but found nothing so I post it for the pictures at least.

 

There was one for sale at an automobile museum about 40 miles from here ten years ago.

Edited by Bob Riebe, 26 January 2024 - 00:32.

[Magoo]

Around 10 years ago or more a guy was constructing a '69 Mustang with a GAA V8. Much of the engine stuck out through the hood as in an Ed Roth T-shirt. I don't know if it was ever completed. 

[Magoo]

There are a number of stories, some possibly true, of how Henry Ford and Rolls-Royce got sideways with each other in the proposed deal for Ford to produce Merlin engines, which then went to Packard instead. 

 

In one story as told by Maurice Olley, who was somehow representing R-R, he was horrified to learn that Ford was proposiing to use a cast ductile-iron crankshaft, which sent Olley to his fainting sofa. Actually, it's quite feasible. Ford did end up building Merlins at Trafford Park. 

Edited by Magoo, 25 January 2024 - 23:51.

[Bob Riebe]

Posted on Reddit two years ago.

 

[Lee Nicolle]

I thought the part about being copy of the Merlin was wrong.

I used the wonderful search engine on this site to see if I had not posted some thing about the GAA beore but found nothing so I post it for the pictures at least.

 

There was one for sale at an automobile museum about 40 miles from here ten years ago.

Having in recent times become interested in WW2 tanks this engine was used in Grant and Lee tanks as well as the Sherman. As well as a 9cyl radial, a 30 cyl Chrysler [5 flathead 6s on a common case] and twin GMC 6 cyl diesels.

To see a radial Grant running see 'The Australian Armour and Artilery museum ' on You Tube. 50+ turns of a crank handle then let it go and away it goes.

An interesting site where they restore, maintain and rusto mod tanks and artilery pieces. While I may get there to have a look in the future I have no interest of ever working on one.

[Greg Locock]

Olley worked for RR in WW1, but then moved to the USA and worked for GM (Cadillac in particular from memory). When RR wanted to get Merlins made in the USA they got GM to release Olley so he could represent RR in the negotiations.

[gruntguru]

https://thunderboats...d-maurice-olley

 

Adds a fair bit to the story - fascinating.

[Greg Locock]

"they used “floating” rod bearings with bearing surfaces on both the inside and out, for longer life and less friction" I think these are called double slippers?

[Magoo]

Charles Sorensen. Ford's production boss, shares a rather different recollection of the Merlin-Ford deal in his autobiography, My Forty Years with Ford. 

 

But then, he is not the most reliable narrator in recounting past events, either. 

 

This is the value of autobiography. In every scene you get to be the smartest, wisest, and kindest person in the room. 

[Wuzak]

There are a number of stories, some possibly true, of how Henry Ford and Rolls-Royce got sideways with each other in the proposed deal for Ford to produce Merlin engines, which then went to Packard instead.  

 

The story I have read is that Henry Ford was willing to build the Merlin, but only wanted them supplied to the US military and not the British.

 

Which defeated the purpose of Rolls-Royce trying to partner with a US manufacturer.

 

Part of the original deal with Packard is that 1/3 of the 9,000 engines were reserved for US aircraft. 

 

That's how there came to be a Merlin powered P-40 (the P-40F and P-40L).

 

 

 

Ford did end up building Merlins at Trafford Park. 

 

Ford UK had been asked to build Merlins before US production was considered. Likely why their first stop was Ford USA.

Edited by Wuzak, 28 January 2024 - 16:08.

[Wuzak]

The US military had little interest in liquid-cooled inline aircraft engines but did have a desperate need for engines to power the Sherman M4 tank. So Ford was asked to make the V12 a V8. Hence the 60 degree bank angle.  

 

 

 

Not strictly the case.

 

The US Military (the Army, primarily) had backed the Allison V-1710 since the early 1930s and had the "hyper" engine program, which aimed to have 1hp/cubic inch and 1hp/lb.

 

The main "hyper" engine was the Continental IV-1430, which started life as a flat V12 of ~1,230 cubic inches before being changed to an inverted vee of 1430 cubic inches. 

 

Continental progress was slow, mainly because the Army ran most of it. 

 

A new factory was built to manufacture the engines, but the engine wasn't ready and the factory was used to build other types, and finished the war building Merlins.

 

Lycoming started their own "hyper" engine, the O-1230. But they soon decided it wasn't gong to be competitive, so they doubled up to make an H-24, the XH-2470. That didn't end up going either. Both the Army and Navy assisted with funding for the X-2470.

 

Wright built the R-2160 Tornado, a 42 cylinder, 7 bank radial. 

 

The bottom end of the Tornado was built as 3 14 cylinder 2 row radials, while the cylinder blocks and heads were an in-line 6 cylinder OHC design. The 3 crankshafts were geared together using 7 layshsfts which drive the propeller reduction gear.

 

Pratt and Whitney built some liquid cooled sleeve valve H-24 engines, some for the Army and some for the Navy.

 

 

The US military observed developments in Europe and could see that the trend was for liquid cooled engines in high performance fighters. So they wanted their own. 

 

The V-1710 was fitted, with turbocharger, to the P-36 to become the X/YP-37.

 

But because of poor turbo reliability, they dropped the turbo and made a new version, the P-40.

 

Other Army fighters under development before WW2 were the P-38 and P-39, both with the V-1710.

 

The original specification for the P-47 was for a lightweight fighter powered by the V-1710.

 

 

The issue in the US was that the air cooled engine manufacturers had a large market in commercial aviation, but makers of liquid cooled engines had to rely on military contracts.

[Magoo]

I don't think any of the hyper engines ever saw production or flew in combat. 

[Bob Riebe]

The Continental hyper-engine came the closest to production.

23 were produced but dealing with the U.S. Govt. and Military in WW II was like betting of 0 or 00 in roulette.

[Greg Locock]

Set silly targets, win silly prizes. Targeting specific power ,hp/cu in, was just engineering willy waving.  

[Wuzak]

I don't think any of the hyper engines ever saw production or flew in combat. 

 

No, they did not.

 

The IV-1430 was proposed for many aircraft, but only flew in two prototypes, the Lockheed XP-49, a cleaned up P-38, and the McDonnell XP-67.

 

It likely never made the claimed 1,600hp in either of those applications.

 

One of the IV-1430s in the XP-67 caught fire in flight and burned the aircraft to the ground after landing.

[Wuzak]

Set silly targets, win silly prizes. Targeting specific power ,hp/cu in, was just engineering willy waving.  

 

These targets would be met by later versions of engines not in the hyper program, such as the Merlin and V-1710.

 

The hyper cylinder, used by the IV-1430, the O-1230/H-2470 and the Chrysler I-2220, was a hemispherical design with 2 valves per cylinder.

 

The plan was to run with coolant temperature as high as 300F (149C), but it was soon discovered that what was saved in cooling radiator size was more than offset by oil radiator size increases.

[Greg Locock]

OK, but to the integration engineer (or platform designer) the cu in are immaterial, weight and installed volume for a given power are useful. 

[Wuzak]

OK, but to the integration engineer (or platform designer) the cu in are immaterial, weight and installed volume for a given power are useful. 

 

True, but the power-to-weight of 1hp/lb was also part of the hyper specification.

 

And the original IV-1430, or I-1430, was designed as a flat engine so that it could fit inside the wing of a multi-engine aircraft.

 

Lycoming's own was a flat 12, the Wright R-2160 Tornado was a small diameter radial that could also fit inside a wing.

 

This was before it was determined that the advantages were not that great, if at all, and wings started to become thinner.

[Wuzak]

When people talk about the Ford GAA engine, I often confuse it with the Ford Cosworth GAA engine.