Maybach HL230

The Maybach HL230 was a water-cooled 60° 23 litre V12 petrol engine designed by Maybach. It was used during World War II in medium and heavy German tanks, namely the Panther, Jagdpanther, Tiger II, Jagdtiger (HL230 P30), and later versions of the Tiger I and Sturmtiger (HL230 P45).

Description
The engine was an upgraded version of the slightly smaller HL210 engine which was used to equip the first 250 Tiger I tanks built, and which had an aluminium crankcase and block. The earlier HL210 engine had a displacement of 21.353 L or 1,779 cm³ per cylinder; bore 125 mm, stroke 145 mm.

With the HL230, engine bore was increased from 125 mm to 130 mm. It had a displacement of 23.095 L or 1,925 cm³ per cylinder; bore 130 mm, stroke 145 mm. The maximum output of 700 PS (690 hp, 515 kW) at 3,000 rpm. Maximum torque is 1850 Nm (1364.5 ft lbs) at 2,100 rpm. Typical output was 600 PS (592 hp, 441 kW) at 2,500 rpm.

The crankcase and block of the HL230 were made of grey cast iron and the cylinder heads from cast iron. The engine weighed 1200 kg and its dimensions were 1000 ×. Aspiration was provided by four twin-choke Solex type 52JFF carburettors. Ignition was by two magnetos. The compression ratio was 6.8:1. As was typical practice for Maybach, the engine used a tunnel crankshaft.

Late in the war the HL234 upgrade with fuel injection was recommended by the Entwicklungskommission Panzer for use in the underpowered Tiger II tank. The power output was expected to increase to between 800 and 900 PS (hp), and with supercharging to 1100 to 1200 hp.

Production
Approximately 9,000 HL230s were produced in total by Maybach, Auto Union and Daimler-Benz.

Beginning on 3 November 1944, they were produced at the Richard I underground factory at Leitmeritz concentration camp.