pinehilljoe
Senior Airman
- 728
- May 1, 2016
Were Packard engines ever considered for tanks. These are not the Merlin, but Packard designs used in PT boats. Packard 1A-2500 - Wikipedia
Other liquid cooled aero engines with tank potential?
- Thread starter Admiral Beez
- Start date
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ThomasP
Senior Master Sergeant
I remember reading that a modified Packard 4M-2500 engine was considered for use in the T28 Super Heavy Tank project, but I do not think it was pursued beyond the early design stage.
Possibly considered but at 40 litres it would most likely have been considered too big and maybe too thirsty to go with it.
Shortround6
Major General
The Aircraft (and PT Boat) Packards date from the 1920s.
The Aircraft versions were unsupercharged and ran a low octane fuel.
However they were not cheap, Packard was looking for over $15,000 an engine in 1930 and that was for a direct drive engine.
Unless you are planning on building tanks over 60 tons they weren't needed.
Packard had a smaller 1500 cu in engine and Curtiss had the 1570 cubic in Conqueror and the 1145 cu. in. D-12 if anybody really wanted them.
How the British wound up with the Liberty engine is a bit of a mystery.
It was the oldest design. perhaps it could be made using older machine tools or less sophisticated factories?
It used a 45 degree angle and might have been a few inches narrower?
The Aircraft versions were unsupercharged and ran a low octane fuel.
However they were not cheap, Packard was looking for over $15,000 an engine in 1930 and that was for a direct drive engine.
Unless you are planning on building tanks over 60 tons they weren't needed.
Packard had a smaller 1500 cu in engine and Curtiss had the 1570 cubic in Conqueror and the 1145 cu. in. D-12 if anybody really wanted them.
How the British wound up with the Liberty engine is a bit of a mystery.
It was the oldest design. perhaps it could be made using older machine tools or less sophisticated factories?
It used a 45 degree angle and might have been a few inches narrower?
Even as late as 1938 there was still confusion as to design types and specs for British tanks. There was what we know as the light tank,
cruiser tank, and infantry tank but there were also designs for 'medium' tanks in the mix. many types were so close it was nearly
impossible to classify a difference. One 'lighter' medium design shifted the two front MG turrets to the top of the main turret giving
a five man turret and also required a transverse V8 to shorten the hull.
The medium designs were originally to be made after looking at four main engine types, the Liberty V12, Meadows v12, Napier Lion,
and finally the one chosen - the Thornycroft RY12 which gave enough horsepower to run a 32 ton tank. The Liberty was the least
powerful and was calculated to be good for a 24 ton tank.
When designs starting getting too heavy a smaller engine with less fuel storage and range was looked for. A version of the Thornycroft
RY12 but as an eight cylinder (RY8) was possible but not in production so somewhere along the line things went back to the Liberty.
cruiser tank, and infantry tank but there were also designs for 'medium' tanks in the mix. many types were so close it was nearly
impossible to classify a difference. One 'lighter' medium design shifted the two front MG turrets to the top of the main turret giving
a five man turret and also required a transverse V8 to shorten the hull.
The medium designs were originally to be made after looking at four main engine types, the Liberty V12, Meadows v12, Napier Lion,
and finally the one chosen - the Thornycroft RY12 which gave enough horsepower to run a 32 ton tank. The Liberty was the least
powerful and was calculated to be good for a 24 ton tank.
When designs starting getting too heavy a smaller engine with less fuel storage and range was looked for. A version of the Thornycroft
RY12 but as an eight cylinder (RY8) was possible but not in production so somewhere along the line things went back to the Liberty.
GrauGeist
Generalfeldmarschall zur Luftschiff Abteilung
Ford's GAA (and GAF) V-8 tank engines were adapted from the GAC V-12 aircraft engine.
The Super heavy tank projects (T29, T34) used the GAC V-12 aircraft engine.
The Super heavy tank projects (T29, T34) used the GAC V-12 aircraft engine.
ThomasP
Senior Master Sergeant
re the continued use of the Liberty engine in British tanks - not the whole answer but a good summary of a large part of the reason, ie the tanks using the Liberty based engine were designed and/or produced by Nuffield Industries and hence used a Nuffield engine.
"Nuffield Mechanizations and Aero - Wikipedia"
"Liberty L-12 - Wikipedia"
"Nuffield Mechanizations and Aero - Wikipedia"
"Liberty L-12 - Wikipedia"
Shortround6
Major General
Doesn't really explain why.
We can guess it was cheap/expedient.
The Christie tank used the Liberty engine because it was cheap (available surplus) and it would fit in the hull.
Christie only built about nine (?) of the noted fast tanks and his claim to fame was the suspension and convertible run on wheels thing.
Now please note how small the hull is (and the fact the turret may only have provision for machine guns or a very short 37mm gun?) and the Christie suspension takes up some room inside the hull walls.
The British Cruiser tanks were wider and a bit longer, Much larger turret. They didn't need quite as skinny an engine (if Christie even did) but the engine layout (radiators, etc) was already done and starting over with new engine, even if better, would mean more engineering time.
Once the hull had been made wider to make a practical tank (AP gun in the turret, practical ammo storage/etc.) the need for a narrow engine went away.
If you are tooling up for new engine the reason to use the Liberty is pretty small, If you can't design your own then you need to licensee an engine, and maybe the Liberty was the cheapest or maybe somebody in Britain already held the license? A number of US companies had made the thing in WW I so it wouldn't surprise me that somebody in Britain signed something even if no engines were actually made before the war ended.
Maybe Nuffield bought into the idea it was a modular engine. V-8s a in-line 6's had been made in small numbers in WW I and maybe he thought it would give him a bigger product line?
We can guess it was cheap/expedient.
The Christie tank used the Liberty engine because it was cheap (available surplus) and it would fit in the hull.
Christie only built about nine (?) of the noted fast tanks and his claim to fame was the suspension and convertible run on wheels thing.
Now please note how small the hull is (and the fact the turret may only have provision for machine guns or a very short 37mm gun?) and the Christie suspension takes up some room inside the hull walls.
The British Cruiser tanks were wider and a bit longer, Much larger turret. They didn't need quite as skinny an engine (if Christie even did) but the engine layout (radiators, etc) was already done and starting over with new engine, even if better, would mean more engineering time.
Once the hull had been made wider to make a practical tank (AP gun in the turret, practical ammo storage/etc.) the need for a narrow engine went away.
If you are tooling up for new engine the reason to use the Liberty is pretty small, If you can't design your own then you need to licensee an engine, and maybe the Liberty was the cheapest or maybe somebody in Britain already held the license? A number of US companies had made the thing in WW I so it wouldn't surprise me that somebody in Britain signed something even if no engines were actually made before the war ended.
Maybe Nuffield bought into the idea it was a modular engine. V-8s a in-line 6's had been made in small numbers in WW I and maybe he thought it would give him a bigger product line?
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MIflyer
1st Lieutenant
The RR Meteor tank engine was based on the Merlin.
Ford was asked if they could build Merlins, examined the RR drawings, and declined. Then later Ford came out with an in-line tank engine and Guess What It Looked Like.
Ford was asked if they could build Merlins, examined the RR drawings, and declined. Then later Ford came out with an in-line tank engine and Guess What It Looked Like.
Shortround6
Major General
How many different ways can you make a V-12????
Once you decide on the 60 Degree V angle (a no brainer) and the cylinder size and proportion ( a little undersquare) a lot the rest starts to fall into place.
Except for the cylinder head, and here Ford used a number of differences.
Once you decide on the 60 Degree V angle (a no brainer) and the cylinder size and proportion ( a little undersquare) a lot the rest starts to fall into place.
Except for the cylinder head, and here Ford used a number of differences.
MIflyer
1st Lieutenant
Well, true, the initial Merlin design did not have removable heads and Packard changed that, too.
But the Liberty was built like the auto engines of its day, separate cylinders. Powerful, perhaps, but not really very advanced. The Curtiss D-12 changed all that, and all the V-12's after it were more or less copies.
Legends of the Sky: The Liberty Plane | KET
Liberty Plane tells the story of the first American airplane mass-produced for WWI efforts
I thought Rolls changed the head design and Packard picked up production at that point?.Well, true, the initial Merlin design did not have removable heads and Packard changed that, too.
But the Liberty was built like the auto engines of its day, separate cylinders. Powerful, perhaps, but not really very advanced. The Curtiss D-12 changed all that, and all the V-12's after it were more or less copies.
Legends of the Sky: The Liberty Plane | KET
Liberty Plane tells the story of the first American airplane mass-produced for WWI effortswww.ket.org
Shortround6
Major General
The Merlin, once they stopped using the ramp head, had all four valves parallel while the Ford used a pent roof combustion chamber, intake valves are sloped way from the exhaust valves at an equal angle to the cylinder bore.
The Merlin uses one cam shaft per cylinder head. It uses two rocker shafts or rather pivots for the rocker arms. The central camshaft lobs bear on the rocker arms part way between the pivot point and the valve stem.
The Ford uses double overhead cams and the cam lobs bear directly on the valve stem buckets.
The Merlin uses one cam shaft per cylinder head. It uses two rocker shafts or rather pivots for the rocker arms. The central camshaft lobs bear on the rocker arms part way between the pivot point and the valve stem.
The Ford uses double overhead cams and the cam lobs bear directly on the valve stem buckets.
Shortround6
Major General
I will submit the theory (not my own) that Ford was working on an aircraft engine for a while.
I do tend to discount the idea that Ford of America got any help/information from Ford of France.
It may be possible that Ford of England sent something to Ford of America, might depend on what level of secrecy they operating under.
For those of us that grew up as the information age formed it is a little tough to understand what it was like in late 30s or 1940s.
Most intercontinental communication was either telegraph or mail. While there were intercontinental phone calls the medium of transmission was radio. First telephone cable between Canada and the UL was laid in 1956. Air mail letters had special thin, light weight stationary/envelopes.
If you wanted to send regular mail it went by ship. If you want to send a few hundred drawings it went in a crate. The crate went to the docks, was put on a suitable ship and was sent on it's way.
Ford of America may well have been aware of the Merlin though articles in the aviation magazines/books of the day. They would have been idiots not to be aware of it.
The 1938 Jane's has three photos and a short description for example.
While microfilm dates back to the mid 1800s it didn't really start to be used until the 1920s-30s. It was increasingly used in industry and a much use was made of it during WW II to reduce the weight of air mail traffic.
RR sent the sample engine and crates of drawings to the US, that was what it was going to take to get an accurate idea of what it would take to make the engine.
I do tend to discount the idea that Ford of America got any help/information from Ford of France.
It may be possible that Ford of England sent something to Ford of America, might depend on what level of secrecy they operating under.
For those of us that grew up as the information age formed it is a little tough to understand what it was like in late 30s or 1940s.
Most intercontinental communication was either telegraph or mail. While there were intercontinental phone calls the medium of transmission was radio. First telephone cable between Canada and the UL was laid in 1956. Air mail letters had special thin, light weight stationary/envelopes.
If you wanted to send regular mail it went by ship. If you want to send a few hundred drawings it went in a crate. The crate went to the docks, was put on a suitable ship and was sent on it's way.
Ford of America may well have been aware of the Merlin though articles in the aviation magazines/books of the day. They would have been idiots not to be aware of it.
The 1938 Jane's has three photos and a short description for example.
While microfilm dates back to the mid 1800s it didn't really start to be used until the 1920s-30s. It was increasingly used in industry and a much use was made of it during WW II to reduce the weight of air mail traffic.
RR sent the sample engine and crates of drawings to the US, that was what it was going to take to get an accurate idea of what it would take to make the engine.
pinehilljoe
Senior Airman
- 728
- May 1, 2016
Microfilm was used in shipping V-Mail around the world. The letters were microfilmed shipped, then processed at the other side of the world.
special ed
2nd Lieutenant
- 5,555
- May 13, 2018
The letters were opened stateside, microfilmed, then destroyed, and the film processed, sent to the APO where the images were printed and (hopefully) delivered. Many of the V-Mail personnel formed the core of the postwar business microfilm industry at Kodak. Earlier than wartime, some mail was sent by train via microfilm. All I remember of that was seeing a "railroad processor" in a shop area.
yulzari
Staff Sergeant
I do realise it goes against the OP but is there any room for the de Havilland air cooled engines?
Even the first V8 Ghost upgraded redesign of the ancient Renault V8 could kick out near 200bhp on near Pool petrol in 1925. Right up to the Gipsy 12 at 425bhp. I suppose the Alfa Romeo Gipsy Major copies could find an Italian use.
Even the first V8 Ghost upgraded redesign of the ancient Renault V8 could kick out near 200bhp on near Pool petrol in 1925. Right up to the Gipsy 12 at 425bhp. I suppose the Alfa Romeo Gipsy Major copies could find an Italian use.
Shortround6
Major General
The Gypsy 12 was too big, after you de rated it, you have an engine as large or larger than a Merlin.
You have to fit the engine and cooling fans inside the armored hull and the weight of armor to put the engine in is against you.
The Gypsy 12 was 31.5 in wide, 37.4 in tall and over 80in wide, but you can change that, take of the reduction gear and the prop shaft and tale the supercharger off the other end.
It was still a big engine on the outside, on the inside it was an 18.4 liter engine (small than a Kestrel), it was also upside down and either needed to be "flipped" or a gear system made to lower the output drive to about where the tank transmission needed it. Flipping an engine means making sure the oil system will work upside down and not just for 20-30 seconds of inverted flight. You also had to get the air flow through the cylinders and out through the V, A liquid cooled engine can have the radiators wherever and connect them with hoses.
You have to fit the engine and cooling fans inside the armored hull and the weight of armor to put the engine in is against you.
The Gypsy 12 was 31.5 in wide, 37.4 in tall and over 80in wide, but you can change that, take of the reduction gear and the prop shaft and tale the supercharger off the other end.
It was still a big engine on the outside, on the inside it was an 18.4 liter engine (small than a Kestrel), it was also upside down and either needed to be "flipped" or a gear system made to lower the output drive to about where the tank transmission needed it. Flipping an engine means making sure the oil system will work upside down and not just for 20-30 seconds of inverted flight. You also had to get the air flow through the cylinders and out through the V, A liquid cooled engine can have the radiators wherever and connect them with hoses.
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Edsel signed the deal.
Henry reneged on the deal because he was ... what he was.
?? RR changed that.
Shortround6
Major General
Packard was in a better place to do it as Packard was buying (or making) all new machinery. RR needed to introduce the new parts/processes to existing production lines without interrupting the flow of engines.
Packard did change a few things, like some of the connections for the coolant passages?
It was pretty much a co-operative effort.
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