Best tank engines of WWII

[Shortround6]

Why?
By the time it was "enlarged" to be suitable for tank use you would have a new engine with no interchangeable parts.
Please read your own reference/s.
The engine in the photo is the original 1929-1939 V-16 with overhead valves and 452 cu/in with 5 main bearings.
The 1938-40 V-16s were flathead 431 cu/in (7.1 l) engines with 9 main bearings and 185hp at around 3400+ rpm.
What were used in tanks were paired flathead V-8 Cadillac engines of 346-349 cu/in each (accounts differ) of 110hp each at 3400rpm. Used in the M-5 light tanks/ M-24 light tanks and their SP gun offspring's. Notice that this 698 cu/in pair was a replacement for the 670 cu/in 7 cylinder radial aircraft engine used in the M-2 and M-3 light tanks.
Even luxury car engines were nowhere near powerful enough for tank use (unless very light tanks).
Heavy truck/industrial engines were powerful enough for light tanks but they were both heavy and large and needed large engine compartments.
Very few countries had access to large truck/bus/industrial engines in part due to tax laws. Many European countries either based some of the purchase price or annual registration fees on size of the engine (sometimes just the bore size) and the taxes on large engines was enough to make production in numbers difficult. The US had no such tax laws based on engine size.

 

[GrauGeist]

Was the Cadillac V-16 considered for tank use in an enlarged form?

View attachment 881595

Not to the best of my knowledge. The later series 90 produced about 185 hp., which in a road car was impressive, but not very practical for a military application.

Most automotive V-12s (and the V-16) look impressive, but they are not really all that large.

Edit: SR beat me to it.

And to expand a little, even the massive GMC 702 cid V-12 of the 1950's would not have been suitable for an AFV, well, maybe the M8 Greyhound.
It was well suited for heavy trucks with it's 275hp. and 630 ft.lb. of torque, but would certainly fall short for any tank application.

 

[Engineman]

Ford's GAA was developed from their XV-1650 V-12 engine, so the bore x stroke would have been fairly close.

BTW, the Packard Liberty 12A was a "1650" with a 5" bore and 7" stroke, making it fairly close to both the V-1650 and XV-1650.

It seems that the 1650 cid engine was an ideal size.

Yes, roughly 20 to 35 litres swept volume in a V12 did produce favourable outputs for many high-end applications, even as the technology advanced from about 1915 to 1940 in aircraft powerplants. The balance was one of mechanical-strength, material specifications limitations, fuels and supercharging. The size and weight of the rotating components associated with larger displacement volumes rapidly becomes very limiting to rpm due to the forces generated. At the same time air/fuel consumption rate is directly linked to the energy generated, so that there are physical constraints on the rpm and power output if you just keep getting larger or spinning faster. You can supercharge the air/fuel mixture to get a greater charge consumption, but the fuels and combustion technology will limit your level of supercharge, not to mention the ability to design a good supercharger.
Rolls Royce found these problems in the early 1930's when they tried to develop their 36.7L Schneider Trophy winning R engine (2500 hp @ 3200rpm/18psi Boost) into a service engine and had difficulty getting a similar de-rated version to 1500bhp when using 87octane fuel and having a usable type rating, ie at least a 100hr type test. Eventually, this line of thought brought some success with the Griffon engines, but only after several redesigns and running on 100/130 octane fuel. However, the Griffon did not eclipse the smaller Merlin.
So, where does this lead us with the large WW2 Tank engines? IMO, the Meteor was obviously a leader with the huge benefit of its aero-engine development background. You just have to accept its slight packaging compromises.
The Maybach HL230 was something of a compromise too far. Too optimised and underdeveloped with design/technology and materials deficiencies.

Eng

 

[z42]

Of course, and good points. But I'm more suggesting the museum's Tiger is better put together, with better components than the originals. It's reported that a Tiger II typically suffered a breakdown after traveling just 50 to 150 km. I expect the museum's example has reliably done much more than this, if only around the grounds. It would be interesting to know how the mechanisms, tolerances, metallurgy and cooling of the museum's example compares with the original - I expect the 21st Century coolants and lubricants used today would be superior for starters.

I would suspect a museum Tiger today doesn't do that many km per year. What would it be, a few km's round the track on some visitor days, and obviously some testing etc. to ensure it actually works on those days. And then the rest of the time it gets to spend in an (air-conditioned?) hangar, under loving care. I mean, seriously, look at the video above you posted. They are driving very carefully at barely walking speed, over a very nice and even track. That looks very far from wartime usage.

Secondly, wrt. lubricants, sure, modern lubricants are a lot better, but they are also made for modern engines with their much finer tolerances. I don't think you'll get happy results if you just throw in the latest fully-synthetic 0W-20 oil in such an old engine. I recall reading, maybe it was on this forum, that for such museum engines, both vehicles and aircraft, they try to find lubricants that match as closely as possible to what the engine was designed for rather than trying to take advantage of the latest and greatest.

 

[Engineman]

Secondly, wrt. lubricants, sure, modern lubricants are a lot better, but they are also made for modern engines with their much finer tolerances. I don't think you'll get happy results if you just throw in the latest fully-synthetic 0W-20 oil in such an old engine. I recall reading, maybe it was on this forum, that for such museum engines, both vehicles and aircraft, they try to find lubricants that match as closely as possible to what the engine was designed for rather than trying to take advantage of the latest and greatest.

Hi,
The subject of suitable lubricants for any machine is quite complicated. When you look at old machines that used old type lubricants, there are always problems of what to use today. Certainly, modern high quality lubricants can have superior lubricating and stability qualities, but the real problem is, will they suit the old machine? Lubrication can be very specific in its requirements, some engines must have special additives and oil specific qualities to function correctly. This can be very specific, for example the Bristol Centaurus engine needs a very specific oil to prevent main bearing failure. However, just trying to use the correct "old" oil is sometimes difficult if the old spec oil is not availiable! Usually though, a good match can be found and there are certainly benefits with some modern oils that suit old machines. There are old oils that were low quality, the Germans suffered from these during WW2, the issue is to avoid using an unsuitable oil of any kind, old or modern.

Eng

 

[Admiral Beez]

Secondly, wrt. lubricants, sure, modern lubricants are a lot better, but they are also made for modern engines with their much finer tolerances. I don't think you'll get happy results if you just throw in the latest fully-synthetic 0W-20 oil in such an old engine.

Fair points. I belong to the CVMG and we have chaps who run 1950s to pre-war bikes who seek out Low-Detergent Monograde oils for this purpose. And then there's the sweet smell of Castor oil used at the vintage races, https://www.vrra.ca. This summer I'm attending the Goodwood Revival with my UK cousins where I expect the lubricants to be very oil school.

 

[Shortround6]

Torque is much more related to displacement than horsepower is. A large, high torque engine in a tank can use a simpler (fewer gears) transmission. A smaller, low torque engine of equal power that runs at a higher rpm needs more gears in the transmission, or torque converters.
A tracked vehicle has roughly twice the rolling resistance of a wheeled vehicle of the same weight on a good surface. This is why even large truck engines only work in light tanks, except large truck engines were often too big to fit in an armored engine bay without excessive weight due to the armored 'envelope'.

British (Nuffield) screwed up the Liberty engine, which had enough problems already, when they redesigned it to be about 7in shorter top to bottom to fit in a shallower hull design to compete with the Meadows engine in the Covenantor tank ( drawing and quartering should have been brought back for whoever approved this thing).

 

[Elvis]

Ford's GAA was developed from their XV-1650 V-12 engine, so the bore x stroke would have been fairly close.

They were the same.
The GAA was a Merlin V-12 with 4 cylinders cut off, so it would've been a little shorter than the V12 engines.

 

[swampyankee]

They were the same.
The GAA was a Merlin V-12 with 4 cylinders cut off, so it would've been a little shorter than the V12 engines.

Although Ford took out the middle four cylinders; they didn't take them from the ends. I suspect this was because they wanted to use the same engine block for the V8 and V12. The GAA was 59 inches long. I couldn't find dimensions for the GAC

 

[GrauGeist]

They were the same.
The GAA was a Merlin V-12 with 4 cylinders cut off, so it would've been a little shorter than the V12 engines.

Ford's XV-1650 (later revived as the GAC) was not a Merlin, but a clean-sheet design.

 

[Elvis]

Ford's XV-1650 (later revived as the GAC) was not a Merlin, but a clean-sheet design.

Gotta link for that?

 

[Shortround6]

Gotta link for that?

For one thing the Merlin used a single camshaft in each cylinder head while the Fords (both V-12 and V-8) used two camshafts in each cylinder head.

and used a different combustion chamber shape.

I have no idea what the differences were in crankshaft area and rods or the actual arrangement of the crankcase and cylinder blocks/heads.

 

[GrauGeist]

I don't have a link but I'm sure info can be found by a quick search.

Ford's V-12 was an aluminum block, cast crank, dual overhead cams (as SR mentioned above), side by side rods, four valve hemispherical cylinder heads and fuel injection based on a Bosch system.

It was not a Merlin clone.

 

[GrauGeist]

A quick search found this extremely well researched and written article that not only covers the XV-1650/GAC develpment, but also provides the timeline of how the U.S. built Merlin came to be.

This may help clear up any confusion

The Ford's, the Merlins and Maurice Olley – Hydroplane and Raceboat Museum

 

[tomo pauk]

A quick search found this extremely well researched and written article that not only covers the XV-1650/GAC develpment, but also provides the timeline of how the U.S. built Merlin came to be.

This may help clear up any confusion

The Ford's, the Merlins and Maurice Olley – Hydroplane and Raceboat Museum

Unfortunately, this:

The Ford GG aircraft V12 showed great potential, producing over 1800 Hp on its initial dyno test!

messes up with the credibility of the article, since the GG aircraft V12 never came to pass.

Also this:

The idea that Ford did not have the ability to build the Merlin, as designed by RR Ltd. is ridiculous. This opinion is proved that to be specious by their British Factory which, starting in 1941, made over 30, 000 Merlin's without one reject!

It was not Ford's factory that made the Merlins in UK, but the ground-up factory made to make Merlins; factory was manages by the Ford of UK/England peaople.

 

[GrauGeist]

messes up with the credibility of the article, since the GG aircraft V12 never came to pass.

Actually, it was produced, Tomo.
Going by memory, 50 GAC V-12s were produced.

While they were not fitted to airframes, they were used in the U.S. Army's prototype T29 and T32 heavy tank projects.

Since I've mentioned the Heavy tank projects, I might also add that the T30 and T34 heavy tank projects, which used a Continental AV1790 air-cooled V-12. It remained in production for many years, both in Gasoline and Diesel versions.

 

[Admiral Beez]

In addition to four stroke gasoline and two and four stroke diesels, were any two stroke gasoline engines tried for tanks or AFVs?

 

[Elvis]

For one thing the Merlin used a single camshaft in each cylinder head while the Fords (both V-12 and V-8) used two camshafts in each cylinder head.
View attachment 881874
and used a different combustion chamber shape.

View attachment 881875
I have no idea what the differences were in crankshaft area and rods or the actual arrangement of the crankcase and cylinder blocks/heads.

...all that and still, no link.

 

[WARSPITER]

This is a good site for the GAA and other GA engine info. Ford GAA Engine

 

[Elvis]

In addition to four stroke gasoline and two and four stroke diesels, were any two stroke gasoline engines tried for tanks or AFVs?

GMC Detroit Diesel 6-71.
Two of them used in a couple of versions of the Sherman tank.
The infamous "Twin-Six" powerplant used two 6-71's coupled to a single transmission.
Not sure how troublesome it was, but the potential was there.