List of WWII Maybach engines

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 component was to be found in a single unified parts list.

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.

[c] According to Albert Speer, Hitler himself never realised this importance: "One of his worst failings was that he simply did not understand the necessity for supplying the armies with sufficient spare parts.

[13] 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.

[14] 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.

[15] According to Stieler von Heydekampf, president of the Panzer Kommission from 1943, German tank production was at a major disadvantage throughout the war because the main firms involved were heavy equipment manufacturers.

It would have been more effective if the programme had been given to Ford Germany and Opel (owned by General Motors) because of their real mass production experience, but this was not done because of their American associations.

[22] On Hitler's orders in March 1944, the extensive cellars below the town of Leitmeritz (now Litoměřice, Czech Republic) on the river Elbe were to be used for the anticipated assembly for HL120 and HL230 tank engines, in case a manufacturing plant were to be bombed.

[13] 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.

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.

Starting in March 1944, a series of Allied precision and area bombing raids put the Maybach factory out of action for several months.

If the various firms making Maybach motors under license had not been in a position to continue producing engines, the German Army's entire tank program would have been seriously jeopardised.

Compared to the NL motors, the HL (high performance) series had a higher compression ratio, which increased the power output.

This advantage was somewhat lost when a mandatory requirement to run on lower-quality OZ 74 (74 octane) gasoline after October 1938 necessitated the compression ratio of the HL series to be lowered, achieved by fitting shorter pistons and a new cylinder head.

In similar fashion, on the HL 57 TU and 62 TUK the compressor was located in a gear-driven housing next to the clutch on the inlet side.

There were two main types: Most models were also fitted with a belt-driven Bosch generator for charging the two 12-volt batteries for the 24-volt electric starter motor; and for 12-volt lighting, etc.

On 4- and 6-cylinder engines the generator was usually connected by a short drive shaft to the separate belt-driven coolant pump, located close to the cylindrical oil cooler.

The second table lists Maybach engines which, although fully functioning, were only made in small quantities and often assigned to projects in the VK series (Versuchskampffahrzeug, "research/experimental fighting vehicle").

Unfortunately, it swiftly became apparent that the Tiger was seriously underpowered, and the rush into production of the new engines meant that the inevitable design defects had not been ironed out.

D) were similarly ill-fated; series production began in January 1943, but when they arrived in Russia in the spring the faults (including the steering and leaking engine gaskets) were so egregious that the entire batch had to be returned to Germany.

[13] A report by Oberstleutnant Reinhold, attached to the 4th Panzer Army during Operation Citadel in July 1943, stated: "Mechanical Deficiencies: The cause for motor failures is still not known.

"[208] Another report from Oberstleutnant Mildebrath for Heinz Guderian, the Generalinspekteur der Panzertruppen in September 1943, about the 96 Panthers of the 2nd Battalion (Abteilung) of the 23rd Panzer Regiment, part of the 23rd Panzer Division: At Kursk, 5–13 July 1943, 25 engines failed within 9 days (these would probably have been HL210 P30s) faults included piston rod bearing damage, broken con rods, damaged pistons, tears (cracks) in the cylinder sleeves, burnt cylinder head gaskets, and water in the exhaust.

A with the HL230 P30 (which didn't arrive in Russia until late 1943) suffered from over-heating, fires in the engine compartment and blown head gaskets.

[cv] The intention was to develop a fuel-injected and supercharged engine, but only the fuel injection mechanism (by Bosch) was working by the end of the war.

[cw] By April 1943 the crankshaft bearings and connecting rods from the HL230 had also been strengthened, and the direct fuel injection system was working - but the supercharger was not yet fully developed.

[229] Problems with rubber seals and copper [head] gaskets were solved by adopting designs used in the Rolls-Royce Merlin engine.

[228] The first HL234 Versuchsmotor was planned to be delivered in early 1945 to the Kummersdorf proving ground and was proposed in January 1945 as an upgraded power plant for the Tiger II, but had not yet been tested in a tank by that date.

[197] Similarly, the E.50/E.75 tank series for which the engine was also intended were never built before the war's end, with only development of individual components taking place.

[235][236][cx] German WWII half-track prime mover numbering may appear not to be strictly logical: the two smallest vehicles were introduced after most of the larger artillery tractors were in production.