List of WWII Maybach engines

 
This is an incomplete list of gasoline engines designed by Maybach AG, manufactured by Maybach and other firms under licence, and fitted in various German tanks and half-tracks before and during World War II. Until the mid 1930s, German military vehicle manufacturers could source their power plants from a variety of engine makers; by October 1935 the design and manufacture of almost all tank and half-track engines was concentrated in one company, Maybach AG, located in Friedrichshafen on Lake Constance.
The firm designed and made a wide range of 4, 6, and 12-cylinder engines from 2.5 to 23 litres; these powered the basic chassis designs for approximately ten tank types (including tank hunters and assault guns), six half-track artillery tractor designs, plus two series of derived armoured personnel carriers. Maybach also designed a number of gearboxes fitted to these vehicles, made under licence by other manufacturers. Friedrichshafen was also home to the Zahnradfabrik (ZF) factory which made gearboxes for Panzer III, IV, Panther and Tiger tanks. Both Maybach and ZF (and Dornier) were originally subsidiaries of Luftschiffbau Zeppelin GmbH, which also had a factory in the town.
Maybach used various combinations of factory letter codes (discussed below) which specified the particular ancillaries to be supplied with each engine variant: the same basic model could be fitted in a number of vehicles, according to the original manufacturer's design requirements. For example, the basic 3.8 and 4.2 litre straight-6 engines (the NL38 and HL42) fitted in various half-tracks could be supplied in at least 9 different configurations, although every single component was to be found in a single unified parts list.
However, as the war progressed, a number of problems hampered the German armaments production effort. The factory's inability to manufacture enough complete engines as well as a huge range of spare parts, meant that there was often a lack of both. Conflicts between the civilian Reich Ministry of Armaments and Munitions and the German Army led to a failure to set up an adequate distribution system, and consequent severe shortages of serviceable combat vehicles. In April 1944 an Allied bombing raid put the Maybach factory out of action for several months, and destroyed the ZF gearbox factory.
By the end of the war Maybach had produced over 140,000 engines and 30,000 semi-automatic transmissions for the German Wehrmacht.
Maybach history, 1935–1945.
In order to rationalise Germany's military vehicle production, sweeping changes were made to its entire automotive industry. , head of the Heereswaffenamt (HWA), oversaw the re-organisation. By late October 1935, Maybach had been designated the sole designer of engines for the army, with production outsourced to other firms including Nordbau (Norddeutsche Motorenbau GmbH) in the south-eastern Berlin suburb of Niederschöneweide beside the River Spree. 
Although a steady supply of spare parts is essential to an army in the field, the production of complete engines always took priority over providing spares. Germany never achieved the industrial capacity needed to keep its military vehicles running efficiently: when the Russian campaign got underway, the deficiencies of the armaments industry and the organisation of maintenance depots became obvious. The German armed forces suffered from continual shortages of spare parts for tanks and half-tracks until the end of the war. When the first Tiger I tanks arrived in Russia in autumn 1942, there was only one spare engine and one transmission for every 10 tanks. A critical lack of spare parts meant that most of them were out of commission within a short period, sometimes for weeks on end. Despite various attempts at re-organisation, friction between the distribution systems of the German Army ("das Heer") and the civilian Ministry of Armaments (and from 1944 the 'Rüstungsstab') often led to confrontation and inefficiency. Some of this can be blamed on Karl-Otto Saur of the Ministry of Armaments, whose ruthless drive for greater overall production figures tended to override the need for testing and durability concerns, and the manufacture of enough spare parts. 
By late 1943 there was a severe shortage of spare tank engines. Rather than concentrate on proven designs, Maybach continued to bring out new, relatively untested models; the wide variety of engine types seriously hampered efforts to fix the multiple defects which Maybach engines developed under combat conditions. The extreme difficulty of stocking so many spares at the front, several thousand kilometres away from the factory, swiftly led to vehicles being unserviceable for combat. Because the armaments industry was already working at full capacity, it was not possible to completely replace obsolete models with new versions. Instead, the number of tank models and types within each series issued to the field forces increased steadily, which only made the maintenance and repair situation worse.
Severely damaged tanks from the Russian front were initially shipped back to Germany, or to the Nibelungenwerk or the Vienna Arsenal for repair; but the prospect of inevitable delays often meant that vehicles were instead cannibalised at the front for parts. Often when a new engine was delivered, there was little left except the hull of the tank it was intended for. Nevertheless, the maintenance crews did their best, often retrieving knocked-out tanks under considerable difficulties.
As the war progressed, new Maybach engines tended to be rushed into production, without adequate testing and development. As a result, they were viewed as unreliable. All the 325 new Panther tanks delivered to Russia in early 1943 had to be returned because of serious defects in the steering; they were underpowered by the HL210 P30 engine, and its replacement, the HL230 P30 (which didn't arrive until late 1943) suffered from over-heating, fires in the engine compartment and blown gaskets.
By way of comparison, the Russian Army used a single basic engine (the V-12 diesel Kharkiv V-2) to power the majority of its tanks – with a few modifications – starting with the BT-7M and its successor the T-34, producing @ 1800 rpm in 1939; the SU-85 and SU-100; the KV-1 and KV-2 (600 hp in 1939); and the IS-2, ISU-122 and ISU-152 and the T-10. Maybach didn't produce a more powerful acceptable engine until late 1943 with the HL230 P30.
Although the German Army used various combat vehicles appropriated from other countries, they continued to be powered by their original engines. Maybach engines were fitted to the German fighting vehicles for which they had been designed.
General design.
A number of Maybach motors shared the same basic design but had different engine sizes, the larger engines having bigger cylinders to increase the capacity. Similar engine designs had shared parts lists, e.g. the NL38 and HL42; the HL57 and HL62; and the HL108 and HL120.
The 6-cylinder Maybach engines used a single Solex 40 JFF II down-draught () carburetor, and earlier V-12s used two. Later V-12s used Solex 52 JFFs.
A hand-cranked inertia starter ("Schwungkraftanlasser") was fitted to the V-12 engines to supplement the Bosch electric starter motor.
Nomenclature.
Introduction.
Maybach used a series of letter codes and numbers to identify specific engine models, namely:
Although these codes usually indicate what ancillary equipment was fitted at the factory (e.g. the HL42 TUKRRM and the HL57 TR), there are some exceptions, discussed below.
The individual engine number and its capacity, the model type, and year of manufacture are hand-stamped on each crankcase. On 6-cylinder models with magneto ignition, this information is found on the magneto housing: e.g.<poem>
codice_1 </poem>
Performance.
This is followed (without space) by the approximate engine capacity (e.g. HL42 = approx. 4.2 litres.)
Lubrication.
In addition, 'T' by itself has no meaning; it is always directly followed by either R or U, but 'R' in this position should not be confused with an (R) signifying a belt drive ("see below"). Furthermore, in some sources engines may be referred to simply as e.g. "a Maybach HL 120 of 300 metric horsepower", which indicates that further information is needed to identify the particular model number.
Compressor.
Some engines (e.g. the NL38 TUK) had the compressor mounted on top of the cam cover at the flywheel end, driven by internal gears (or perhaps a chain). On other models (e.g. HL38 TUKR) the compressor was mounted on one or other side of the engine, driven by an extra belt at the radiator end. On the HL 57 TU and 62 TUK the compressor fitted in a gear-driven housing next to the clutch on the inlet side. Thus the lack of an 'R' in the model number doesn't necessarily mean that a compressor wasn't fitted.
Installation.
These letters were only used on some models, e.g. HL42 TRKM S, HL45 Z, HL230 P30. The HL230 P30 was designed to be fitted in the Panther, whose prototype was the 30-ton class VK30.02; the HL230 P45 went in the Tiger, whose final 45-ton class prototype was numbered VK45.01.
Examples.
DSO8.
An exception to the naming system outlined above is the V-12 DSO8 fitted to early Sd.Kfz. 8s. John Milsom mentions two versions, one with a power output of 150bhp fitted to the prototype DB ZD5 as early as 1931, and one of 200bhp found in the early production Sd.Kfz. 8 (DB s 7) from 1934-6. Further details, including the actual engine capacity, seem scarce.
The DSO8 also powered three Swedish Stridsvagn m/31 prototypes in the early 1930s. A 150hp DSO8 is also found in the Strv FM/31 Landsverk L-30 dating from 1931, examples of both are preserved in the Arsenalen Försvarsfordonsmuseum in Strängnäs, central Sweden.
Development of the HL210 and HL230.
[[File:Bundesarchiv Bild 101I-022-2936-27, Russland, Panzer VI (Tiger I), Wartung.jpg|thumb|Repairs on a Maybach HL210.<!-- Should have gone to Spec Savers... P45 on an early Tiger Ausf. H (one of 250 built).
External links.
[[Category:Engines]]