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, 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 factory which made gearboxes for Panzer III, IV, Panther and Tiger tanks. Both Maybach and ZF were originally subsidiaries of Luftschiffbau Zeppelin GmbH, which also had a factory in the town.
Maybach used various combinations of factory letter codes which specified the particular ancillaries supplied with each variant; the same model could be used in a variety of applications, according to the original vehicle maker's design requirements. For example, the basic 3.8 and 4.2 litre straight-6 engines fitted in 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.
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, 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 in the Berlin suburb of Niederschöneweide.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 civilian Ministry of Armaments and the Army often led to confrontation and inefficiency.
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 suffered from over-heating, fires in the engine compartment and blown gaskets.
By way of comparison, the Russian Army used a single basic engine 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 ; 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.
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 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:- NL / HL – performance
- TU / TR – lubrication
- K – clutch
- R / RR – belt drives for compressor and fans
- M – magneto ignition
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.
MOTOR Nr 730192
4198 ccM.
HL42 TUKRM
1943
Performance
- NL = Normalleistung
- HL = Hochleistung
Lubrication
- TR = Trockensumpfschmierung, generally fitted to tanks - because of low ground clearance, and to some half-tracks. There is no sump below the crankcase: the engine oil is contained in a tank on one side. On later V-12s there is a tunnel through the oil tank, through which the hand crank for the inertia starter passes, operated from the outside rear of the vehicle.
- TU = Tiefer Unterteil, only fitted to some half-tracks. The sump has an inverted triangle shape, bolted to the underneath of the crankcase housing.
Transmission
- K = Kupplung or Kupplungsgehäuse : a clutch is attached directly to the flywheel end of the crankshaft, driving a manual gearbox. This type of transmission was fitted to most half-tracks, both TR and TU types, and to early Panzer Is. The gearbox could also have a rear power take-off shaft fitted, to power a gun or crane turntable on half-tracks such as the Sd.Kfz. 9/1.
- If there is no factory-fitted clutch, this indicates a tank engine. Instead, a horizontal cardan shaft connects the flywheel to a separate gearbox next to the driver. This could be a pneumatically-controlled, pre-selector Maybach-Variorex ; or a synchromesh ZF Aphon ; or a hydraulically-controlled Maybach-Olvar.
- *A 10-speed Maybach-Variorex SRG 328 145 gearbox was fitted in Panzer IIIs Ausf. E–G, operated by vacuum pressure generated by a compressor - see next section. The main clutch is integral to the gearbox housing.
- *Other tank gearboxes included the synchromesh ZF Aphon SSG 5x and 7x series gearboxes. The main clutch was bolted to the gearbox on the SSG 75, and incorporated into the main housing in the 77. The SSG 77 gearbox replaced the mechanically vulnerable Variorex in the Stug. III Ausf. C. Bigger tank engines used a Maybach-Olvar hydraulically-operated gearbox such as the Olvar EG 40 12 16, fitted to Tiger Is and IIs.
- * Some half-track gearboxes also included a power takeoff shaft driving an external winch.
Compressor
- R = Riemenantrieb für Luftpresser, driven by a pulley at the other end from the flywheel. This was connected to various types of equipment, including:
- *Panzer III and Stug III – Maybach Variorex SRG 328 145 pre-selector gearbox
- *Sd.Kfz. 10 and 250 – Variorex VG 102 128H pre-selector g/box
- *Sd.Kfz. 11 and 251 – air brakes on towed equipment
- *Sd.Kfz. 6–9 – pneumatic foot/parking brake + towed equipment
- KR = Clutch and compressor: production versions of the Demag half-tracks, the Sd.Kfz. 10 and Sd.Kfz. 250 were fitted with a Maybach SRG, type VG 102 128H, with 7 forward and 3 reverse gears. Although they worked on the same vacuum principle as the bigger tank pre-selector gearboxes, these types had no integral clutch, and were much smaller than those fitted to tanks. The drive passed through a standard clutch attached to the engine via a cardan shaft into the gearbox: depressing and releasing the clutch pedal simultaneously disengaged the main clutch and actuated the vacuum pistons to engage the pre-selected gear ratio.
- KRR = Clutch, compressor, and extra belt drives for radiator fans: fitted to a number of Sd.Kfz. 11 and 251 variants. A triple V-belt pulley mounted at the top of the engine also drove the twin cooling fans mounted directly between the engine and the radiator.
Ignition
- M = Schnapper-Magnetzündung : some models had a Bosch 12-volt magneto for the ignition. On 6-cylinder engines, the magneto is geared to the starter ring on the flywheel. On 12-cylinder engines the magnetos were located either on the camshaft ends, or between the cylinder heads, driven by a large internal helical-cut ring gear.
- The alternative to a magneto was an ignition coil connected to a vertically-mounted distributor, often driven from one end of the camshaft.
- Most models were also fitted with a belt-driven dynamo for charging the batteries for the electric starter motor, lighting, etc. On 4- and 6-cylinder engines the dynamo was usually connected by a drive shaft to a separate coolant pump located close to the cylindrical oil cooler.
Installation
- P = Panzerkampfwageneinbau
- Z = Zerstörereinbau
- S = Schleppereinbau
Examples
- NL38 TRKM = Normal performance 3.8 litre, dry sump, clutch, magneto
- HL62 TR = High performance 5.7 litre, dry sump, pre-selector gearbox, no compressor, ignition coil & distributor
- HL108 TUKRM = High performance 10.8 litre, wet sump, clutch, compressor, magneto
Gallery
List of Maybach engines
Model | Type | Capacity | Power | @rpm | Application |
HL25 | I-4 | 2.5 | 65 | 2,800 | Pre-production Sd.Kfz. 10 D4 |
HL30 | I-4 | 3.0 | 95 | 3,000 | Le.WS - Leichter Wehrmacht Schlepper |
NL38 TRKM | I-6 | 3.817 | 90 | 3,000 | Panzer I Ausf. B and derivatives, e.g. 15 cm sIG 33 auf Panzerkampfwagen I Ausf B: Sd.Kfz. 10 D6 : early Sd.Kfz. 11 |
NL38 TUK | I-6 | 3.817 | 90 | early Sd.Kfz. 6 | |
HL38 TUKR | I-6 | 3.817 | 100 | 2,800 | Sd.Kfz. 11 |
HL42 TRKM | I-6 | 4.170 | 110 | Sd.Kfz. 10 type D7 : | |
HL42 TUKRR | I-6 | 4.198 | 100 | Sd.Kfz. 11: Sd.Kfz. 251 | |
HL42 TUKRM | I-6 | 4.198 | 100 | 2,800 | Sd.Kfz. 250: Sd.Kfz. 11, Sd.Kfz. 251 |
HL42 TRKM-S | I-6 | 4.198 | 100 | 3,000 | Leichter Wehrmachtschlepper Schwerer Wehrmachtschlepper |
HL45 P | I-6 | 4.678 | 105 | Panzer I Ausf. C/F and Ausf. J | |
HL45 Z | I-6 | 4.678 | 105 | 2,800 | HKp 602/603 |
HL50 P | I-6 | 4.995 | 110 | 3,000 | Kätzchen APC · HKp 603/604 |
HL52 TU | I-6 | 115 | Sd.Kfz. 7, 1st prod models | ||
HL54 TUKRM | I-6 | 5.420 | 120? | 2,600 | Sd.Kfz. 6 |
HL57 TR | I-6 | 5.698 | 130 | 2,600 | Panzer II Ausf. a |
HL57 TU | I-6 | 5.698 | 130 | 2,600 | Sd.Kfz. 7, 2nd batch |
HL62 TR/TRM | I-6 | 6.191 | 140 | Panzer II Ausf. b–F: Wespe | |
HL62 TUK | I-6 | 6.191 | 140 | 2,600 | Sd.Kfz. 7, 3rd batch |
HL64 | I-6 | 6.4? | 160 | Sd.Kfz. 7 after 1943 | |
HL66 P | I-6 | 6.754 | 180? | 2,800 | Panzer II Ausf. G and L |
SHL66 | I-6 | 6.754 | Used in Pionierschnellboot | ||
HL80 | I-6 | 8.0? | 160? | 2,600 | Sd.Kfz. 7 |
HL85 TUKRM | V-12 | 8.505 | 185 | 2,500 | Sd.Kfz. 8 |
HL90 | V-12 | 9.0 | 200 | 3,000? | Heuschrecke 10 - Grasshopper SPG |
HL98 TUK | V-12 | 230 | Sd.Kfz. 9 | ||
HL108 TR | V-12 | 10.838 | 250 | Panzer III Ausf. A through D: Panzer IV Ausf. A | |
HL108 TUKRM | V-12 | 10.838 | 250 | 3,000 | Sd.Kfz. 9 |
HL116 | V-12 | 11.048 | 250 | 3,300 | Sturer Emil : HK1600 |
HL120 TR | V-12 | 11.867 | 300 | 2,000 | Panzer III, Ausf. E: StuG III Ausf. A: Panzer IV Ausf. B, early C |
HL120 TRM112 | V-12 | 11.867 | 300 | Panzer III, Ausf. F-N: StuG III: StuG IV: Hummel: Panzer IV Ausf. later C-J: Elefant: Brummbär | |
HL157 P | V-12 | 15.580 | 410? | 3,000? | VK 1602 Leopard |
HL174 | V-12 | 19.144 | 450 | 3,000 | VK 3601 H |
HL210 P30 | V-12 | 21.353 | 650 | 3,000? | First 250 Panther Ausf. Ds |
HL210 TRM P45 | V-12 | 21.353 | 650 | 3,000 | first 250 Tiger Is |
HL224 | V-12 | 22.4 | 680? | 3,000 | VK 6501, |
HL230 P30 | V-12 | 23.095 | 700 | Later Panther Ausf. Ds, all As and Gs Jagdpanther, Tiger II, : Jagdtiger : Sturmtiger : Panther II | |
HL230 P45 | V-12 | 23.095 | 700 | 3,000 | Later versions of the Tiger I and Sturmtiger |
HL234 | V-12 | 23.88 | 800 | 3,000 | Panther II |
Development of the HL210 and HL230
A proposed replacement for the Panzer IV had been considered since around 1937. What became the Tiger tank went through a series of specifications, with the final revision being made in May 1941. Only a month later, the German armies invading Russia encountered the superior T-34 and KV-1: by December 1941 a specification for a 30-ton medium tank had been proposed as an immediate response to the Soviet tank threat.Development of the two tanks continued simultaneously: the Tiger prototype was demonstrated to Hitler on his birthday in April 1942, and the first of two Panther prototypes was ready in August 1942.
The weight of the Tiger had increased considerably since its inception, and although it was now considerably heavier than the Panther medium tank, Maybach proposed fitting almost exactly the same 21-litre V-12 650 hp engine in both tanks. To save weight, the cylinder block was cast in aluminium alloy, with cast iron liners. The pistons were made of low-expansion aluminium-silicon alloy with Si content of nearly 20%. The engine for the original 30-ton Panther project was the Maybach HL210 P30, while the 45-ton specification for the Tiger received the HL210 P45. The only visible difference was the arrangement of the coolant ducts exiting the cylinder heads, since the Panther and Tiger had different flows through their radiators.
Quantity series production of the PzKpfw VI Tiger with the HL210 P45 engine began in August 1942, and it is possible that production of the Panther's HL210 P30 was begun at much the same time. The first battalions to be equipped with the Tigers were the 502nd Heavy Panzer Battalion on the Eastern Front near Leningrad, and the 501st Heavy Panzer Battalion which was sent to Tunisia. 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. Nevertheless, when the new Tigers arrived in Russia, 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.
The first PzKpfw V Panthers were similarly ill-fated; series production began in January 1943, but when they arrived in Russia in the spring the faults were so egregious that the entire batch had to be returned to Germany. A special plant for rebuilding the Panthers was established near Berlin.
In the meantime, Maybach re-designed the HL210, replacing the alloy cylinder block with a traditional cast-iron one. Although there was no space for a physically larger engine, the cylinders were capable of being bored out without compromising the engine's integrity. The new HL230 23-litre engines were installed from May 1943 in the latest production Panthers as the P30, and in Tigers as the P45.
Despite all the changes, the up-engined Panther Ausf. A with the HL230 P30 suffered from over-heating, fires in the engine compartment and blown head gaskets.
;Identifying HL210 and HL230 types:
- HL210: three air filters; magnetos are located separately at the end of each camshaft; on the oil cooler side the oil filter sits at a relatively upright angle, approx. 70°.
- HL230: two air filters: magnetos are located centrally in a twin housing between the cylinder heads; oil filter sits at approx. 45°.
- P30: the twin cast iron hot coolant ducts are symmetrical and visually similar, with separate feeds to l.h and r.h. radiators..
- P45: the coolant ducts are siamesed into a single pipe leading to the r.h. radiator.
Half-tracks
- Sd.Kfz. 10, 3.7 cm PaK 36 & 5cm PaK 38, and SP 2cm Flak 30
- Sd.Kfz. 11, 7.5 cm Pak 40 & 41, 10.5 cm leFH 18 and 15 cm sIG 33
- Sd.Kfz. 6,
- Sd.Kfz. 7, 8.8 cm Flak, 10 cm K.18, 15 cm sFH 18; SP for 3.7 cm Flak & 2cm Flakvierling
- Sd.Kfz. 8, 10.5 cm FlaK 38, 17 cm Kanone 18 and 21 cm Mörser 18
- Sd.Kfz. 9, 35.5 cm Mörser, 24 cm Kanone 3, 6 or 10-ton crane, or tank recovery