Why no Luftwaffe-derived engines in Heer vehicles?

[Shortround6]

By the way, Daimler's MB500 series marine diesels were based on the DB600 engine.

Most of them were based off the DB 602 which had absolutely nothing to do with the DB 600, 601 or 605.

The DB 602 was a v-16 diesel of about 2000kg that powered the two Hindenburg class airships.

 

[Shortround6]

I find it interesting that the Italians used diesels in their tanks instead of designing something off of their aircraft engines. With a limited industrial base, Italy seems a good candidate for consolidation of designs across services.

Italian tanks weren't big enough to either require or house engines derived from aircraft engines.

With weights around 12-14 tons depending on model, engines of under 150hp could give then decent even if not sprightly performance.

The Italian heavy tank

The P 26/40 weighed about 26 tons and Italy had trouble supplying and engine for it.

An important consideration for a tank engine is how compact it is, a light but physically large engine requires a larger hull to hold it and the extra armor eats up any weight saving of a lighter engine.

 

[Milosh]

Mercedes-Benz 500 Series Diesel Marine Engines
Mercedes-Benz 500 Series Diesel Marine Engines

 

[Shortround6]

Why didn't German army vehicles use aeroplane-derived engines?

I think the question should be why did the British use at Merlin derived Meteor engine in the most of their tanks from mid war onwards and two petrol engines in the Matilda II.

I could hsee the Junkers Jumo 210 being evolved as a tank engine but the HL120 and HL230 were perfectly adäquate

Until you get to tanks of around 30 tons or heavier Aircraft type engines are not needed. Depends a bit on the engine and the tank, The US M2-M3 used a small 7 cylinder trainer engine but that may not be what people are thinking?
The Matilda II came in both diesel and gasoline versions but the engines were originally built for buses so they were in production (available and cheap), The A9 and A10 used a different bus engine.

Half-tracks, armoured cars and large military trucks don't need aircraft type engines, even trainer type engines.

The Jumo 210 was pretty much a non starter as it was inverted (harder to work on in a tank) and was about 19 liters so the Maybach HL 210 and HL 230 were going to make about the same power if run on the same fuel. The Jumo 210 might have worked if flipped over and a few other modifications but why bother, it had no real advantage.


The British trapped themselves with the LIberty engine. In part because of a lack of large truck engines. Legend has it that the Churchill used two Bedford truck engines on a common crankshaft/crankcase and that was not powerful enough for the weight of the tank. The Liberty required a large engine compartment which meant the Meteor was pretty easy to drop in.
For the British the engine used in the Covenanter was pretty much a flop and may have soured them on purpose built engines? or simply left them without enugh time to design anything else.
The Meteor was actually too powerful for the Cromwell, the suspension (and crew) could not stand up to the speeds the tank was capable of and later versions were regeared to limit the speed to about 80% of the first tanks.

The Meteor would have been great for a 40 ton tank, unfortunately the Centurion grew to about 50 tons pretty quick.

 

[Reluctant Poster]

Until you get to tanks of around 30 tons or heavier Aircraft type engines are not needed. Depends a bit on the engine and the tank, The US M2-M3 used a small 7 cylinder trainer engine but that may not be what people are thinking?
The Matilda II came in both diesel and gasoline versions but the engines were originally built for buses so they were in production (available and cheap), The A9 and A10 used a different bus engine.

Half-tracks, armoured cars and large military trucks don't need aircraft type engines, even trainer type engines.

The Jumo 210 was pretty much a non starter as it was inverted (harder to work on in a tank) and was about 19 liters so the Maybach HL 210 and HL 230 were going to make about the same power if run on the same fuel. The Jumo 210 might have worked if flipped over and a few other modifications but why bother, it had no real advantage.


The British trapped themselves with the LIberty engine. In part because of a lack of large truck engines. Legend has it that the Churchill used two Bedford truck engines on a common crankshaft/crankcase and that was not powerful enough for the weight of the tank. The Liberty required a large engine compartment which meant the Meteor was pretty easy to drop in.
For the British the engine used in the Covenanter was pretty much a flop and may have soured them on purpose built engines? or simply left them without enugh time to design anything else.
The Meteor was actually too powerful for the Cromwell, the suspension (and crew) could not stand up to the speeds the tank was capable of and later versions were regeared to limit the speed to about 80% of the first tanks.

The Meteor would have been great for a 40 ton tank, unfortunately the Centurion grew to about 50 tons pretty quick.

The Churchill engine was a bespoke design. It was sidevalve while the Bedford truck engines were OHV. The side vavle arrangement reduced engine width.
The meteor powered Centurion had a a combat record second to none.

 

[Reluctant Poster]

Cheers, Dave.
Care to elaborate the quoted sentence?

The Chiertain's Hatch has excerpts from reports on the two main engines used by the US army, the Continental and the Ford. The preference was for the Ford. They didn't like the Chrysler as much and sent most of them to the British. The Marines received diesels as it was the same engine used in landing craft and of course the Soviets wanted diesels. The twin 6-71 was the same power plant used in Canadian built Valentines sent to Russia. It seems the Continetal was underpowered for the Sherman. I believe the radial was also more finicky when it came to fuel requiring 87 octane as opposed to the 80 octane supplied to the army, but I cannot relocte the referenc. the radials tendency to catch fire can't have endeared it to the troops.
The Chieftain's Hatch: ETO Equipment Reviews, Pt 2

 

[Shortround6]

The meteor powered Centurion had a a combat record second to none.

That it did even though it was often criticized for it's slow speed.
However combat mobility is often somewhat disconnected from speed on level roads with good surfaces.
The Centurion was noted for it's ability to climb hills, even if slowly, that other tanks could not. Low gear in transmission?
Many tanks had similar cross country speeds. Often the cross country speed was limited by the suspension's ability to absorb shocks and keep the crew from bouncing around the inside of the tank.

Early Centurions had a very short range but that was due, in part, to limited fuel capacity under armor.
However a few other tanks may have rather exaggerated ranges because in practice they did not travel in high gear (most miles per gallon) but sometimes "cruised" in a lower gear.

 

[Reluctant Poster]

The Soviets also used a lot of aero engines in their tanks. The 5,000 plus BT 7s which did much of the initial fighting were powered by the Mikulin M17 which was based on the BMW VI. This same engine was used in some early production T-34s due to a shortage of V-2 diesels. There seems to be some debate over whether the V-2 was originally intended for aircraft. If one was going to design a tank engine from scratch cast iron would be the more logical choice In lieu of aluminum. Note that Packard was at one time going to build the Rolls Royce Meteor but in cast iron.

 

[Shortround6]

Note that Packard was at one time going to build the Rolls Royce Meteor but in cast iron.

Not sure what they would put it in unless some of the experimental heavy tanks T-28 and T-29 series? The T-29 got the Ford V-12.

 

[Shortround6]

I believe the radial was also more finicky when it came to fuel requiring 87 octane as opposed to the 80 octane supplied to the army, but I cannot relocte the referenc.

Troops may have tried to run them on 87 octane, assuming they could get it, a huge assumption in a combat zone.

In 1953 the US Army was listing 80 octane fuel as the required fuel for M4 tanks using the Continental R-975 as per TM-9-2800-1,
In fact nearly all US tanks at the time used 80 octane fuel. The only exception might be the M24. The M-24 is listed as using 80 octane but 3 different self-propelled guns using the M-24 chassis/drive train are listed at 70 octane? Power plants were twin Cadillac car engines.

No other vehicle used 87 octane fuel, quite a number of trucks and cars used 70 or 72, the Jeep is listed as using 68 octane although I highly doubt there was a seperate fuel supply.

combat aircraft were going to use 100 or 100/130 in WW II.
Some trainers used 87 octane but there should have been very few, if any, trainers in a combat area in WW II, or Korea, so supplies of 87 octane fuel should have been nonexistent.
The Grasshopper planes used 73 or 80 octane. I don't know if they had aviation fuel or used truck fuel (possible in emergency?)

 

[davebender]

Radial aircraft engines are not designed for prolonged operation at idle speed. Tanks spend more time idling then moving at high speed. Early production Sherman tanks with radial engines had a big problem with spark plugs fouling prematurely.

 

[Reluctant Poster]

Not sure what they would put it in unless some of the experimental heavy tanks T-28 and T-29 series? The T-29 got the Ford V-12.

The Packard proposal was in October 1941 and was intended to substitute for the Liberty in British tank production. The stoke was to be shortened to 5 1/2 inches with a similar crankshaft but cheaper material. Crankcase, blocks and heads in cast iron. Cylinder liners and pistons as per std Merlin. Valves, camshafts, drives per std Merlin. Weight ~1700 lb.
Cast iron versions were proposed from time to time and some prototypes were built but did not enter production.

 

[Reluctant Poster]

That it did even though it was often criticized for it's slow speed.
However combat mobility is often somewhat disconnected from speed on level roads with good surfaces.
The Centurion was noted for it's ability to climb hills, even if slowly, that other tanks could not. Low gear in transmission?
Many tanks had similar cross country speeds. Often the cross country speed was limited by the suspension's ability to absorb shocks and keep the crew from bouncing around the inside of the tank.

Early Centurions had a very short range but that was due, in part, to limited fuel capacity under armor.
However a few other tanks may have rather exaggerated ranges because in practice they did not travel in high gear (most miles per gallon) but sometimes "cruised" in a lower gear.

You original post implied that the Meteor was inadequate for the Centurion. Its mobility and reliability were as good or better than most of its contemporaries. The truly underpowered tank was the M26.

 

[Deleted member 68059]

Why didn't German army vehicles use aeroplane-derived engines?

Well they did TRY to....Panzer VIII Maus.

However broadly I cant imagine a worse tank engine than an aero engine.

1) Aero engines are hideously expensive because they have to be very high output AND very low weight and very small size. At least 1 and probably 2 of those
dont matter for a tank.

2) Aero engine systems are designed to work at high altitudes, in a tank this gadgetry is rendered moot.
(you can just take the supercharger off, but thats all design work).

3) Aero engines need high grade fuel, very limited supply and hard to transport because the sources are few, and immobile.
(you can just detune them, but then you lose much of the high power density advantage)

4) Aero engines are not designed to get abused, they dont like being idled for long periods, they dont like dirt and
they dont like getting overheated in cramped conditions.

All of these things can be "designed out", by which point its not really an aero engine anymore.

The only situation in which you ought to put one in a tank, is if you`ve been stupid enough not to design a proper
tank engine in the first place. I`d also say that any sensible tank engine ought to be diesel, which also counts out
just about any (western) aero engine other than a Jumo 205.

 

[swampyankee]

Well they did TRY to....Panzer VIII Maus.

However broadly I cant imagine a worse tank engine than an aero engine.

1) Aero engines are hideously expensive because they have to be very high output AND very low weight and very small size. At least 1 and probably 2 of those
dont matter for a tank.

2) Aero engine systems are designed to work at high altitudes, in a tank this gadgetry is rendered moot.
(you can just take the supercharger off, but thats all design work).

3) Aero engines need high grade fuel, very limited supply and hard to transport because the sources are few, and immobile.
(you can just detune them, but then you lose much of the high power density advantage)

4) Aero engines are not designed to get abused, they dont like being idled for long periods, they dont like dirt and
they dont like getting overheated in cramped conditions.

All of these things can be "designed out", by which point its not really an aero engine anymore.

The only situation in which you ought to put one in a tank, is if you`ve been stupid enough not to design a proper
tank engine in the first place. I`d also say that any sensible tank engine ought to be diesel, which also counts out
just about any (western) aero engine other than a Jumo 205.

Guiberson R-1020 and Packard R-980 were both aircraft engines was a US aircraft diesel adapted to use in tanks, and used in quantity.

There are probably vast numbers of reasons why Germany didn't use aero-derivative engines in their tanks, starting with lavish pre-war spending on tank development and continuing with a supply system that didn't try to consolidate multiple streams of government procurement until fairly late in the war. While there were certainly issues in US tank design (example: in the M4 Sherman, the engine was in the rear, but the transmission was at the front, meaning that the drive shaft had to run forward, pushing the height of the tank up by something like a foot or so) and poor production decisions (by late 1942 the idea of tanks not fighting tanks should have been a dead issue; it was obvious from experience in North Africa that tanks did fight tanks and all tanks should be designed with that expectation in mind. I don't think this requires a high-powered retroscope; the Tiger tank was in service in August 1942 and served in North Africa).

(struck out text corrected; my thanks to Shortround6)

 

[Shortround6]

The German tanks also had engines in the rear and transmissions in the front. So did some other countries or companies. Some people thought having the drive sprocket at the front allowed for more mud and crap to fall out of the tracks before the sprocket engaged the track. There was also the question of balance. The transmission and steering gear could weigh almost as much as the engine. On the early tanks there was the question of what you put in the nose aside from the driver and hull gunners feet.
Packaging got better in later tanks.
Part of the problem with the Sherman was the height of the radial, even with a step-up gear set that lowered the drive line from the center of the engine. Inline engines with the crankshaft at the bottom had a lower drive line even if they did add a bit to the height.

The Packard radial diesel was out of production by 1931, I doubt any went into a production tank.

 

[Thos9]

By the way, Daimler's MB500 series marine diesels were based on the DB600 engine.

I think you meant the V-16 DB602 airship engine, not the inverted V12 airplane engine.

 

[GrauGeist]

I think you meant the V-16 DB602 airship engine, not the inverted V12 airplane engine.

I think I meant exactly what I said, but perhaps I should have fought my spell check better.
The first of the MB500 SERIES as I correctly stated were derived from the LOF2 (DB602 V-16, not DB602 V-12), which was an aircraft engine used in airships.

However some later versions in the MB500 series WERE based on other, later DB 600 (V-12) engines: MB507-DB603, MB517-DB603.

The S-Boat was not the only fast boat with engines of aircraft heritage, the USN's PT-Boat had Packard V-12 engines based on the Liberty L-12.

 

[Shortround6]

The Packard Marine engine was based off the Packard aircraft engines of the 20s. The only thing they really had in common with the Liberty engine was that they were both V-12s.

 

[GrauGeist]

The Packard 3A-2500 was derived directly from the L-12A. The 3M-2500, 4M-2500 and 5M-2500 are marine versions of the 3A-2500.

I appreciate splitting hairs, but in the end, the PT-boats engines were based on aircraft engines, no matter how hard you spin it.