These engines are  manufactured by Göbler Hirthmotoren.

-Sometimes known as Hirth simply. These products manufactured by Göbler have nothing to do with the Hirth engines from Hellmut Hirth before and during WWII.

“Logo Göbler - Hirthmotoren”

-Hellmuth Hirth died in a plane crash in July 1938, and in 1941 "Ernst Heinkel AG - Hirth Motoren" took control of the company.

-After the war, the production of engines ceased due to the conditions that were imposed by the Allies.

-Later, "Hirth Motorenwerke KG" made small two-stroke engines in Benningen.

-Because of the growing snowmobile and ULM market, Hans Göbler acquired full production rights and founded "Göbler-Hirthmotoren KG".

“Solo-Hirth range”

-The new engines were derived from the known "Solo" (sometimes "Solo.Hirth") until the last ones, which are from 3.5 to 130 CV.

-For example, the Solo 560 was the G-Hirth F10. They were used a lot before 1960.

-At the same time as this well-known engine, the ones, of which we would say series 100 and 200, were made. See above list.

-From these engines would transcend the 260 until nearly today, together with its variants 261, 262 and 263. They are known by the letter F prefix or without it.

-All Göbler-Hirth engines have a solid and conservative construction, but 2-stroke.

-The installation as auxiliary engines in gliders and motor-gliders was very extensive during the first period.

-An example is the two-stroke, four-cylinder F102A2 engine, which was twin-mounted on the Schleicher K-14, giving 26 CV each.

-Also on the twin-engine Superlab.

“Hirth on twin-engine aircraft”

-The Göbler-Hirth 171R4E inline, 2-cylinder had a displacement of 630 cc and gave 40 CV at 6,500 rpm.

“0-28”

-The 0-28 that was very much derived from the Solo, as we can see, had two cylinders, used the 2-stroke system and gave 55 CV.

“F22”

-Göbler-Hirth presents its engines in family groups, as we see below: the F10A (Solo 560), was made for 26 CV.

-It was a horizontally-opposed, 4-cylinder, 2-stroke, air-cooled engine, but with only 570 cc.

-It had four Tillotson carburetors, an individual one for each cylinder.

-There was a simple Bosch ignition and manual starter. It used reduction gear, on the Akaflieg Karlsruhe AK-1, for example.

-The F22 gave 23 CV and the F23 delivered 40 CV (1982/88). They were two-cylinder boxers and continued to be 2-stroke engines.

-From the F23, the AS, BS and ES are derived.

“F23”

-They are compact and light, with diaphragm carburetors or gasoline injection.

-The cylinders have Nikasil coating and simple ignition. With a displacement of 521 cc they give 50 CV at 6,300 rpm.

-As an option it can have double ignition, G-40 mechanical reduction gear or G-23 belt gear.

-There are the mentioned versions that adapt these options.

“F23-AS, BS, ES”

-The F30 engines are perhaps the most used recently.

“F30”

-They have four horizontally opposed cylinders with carburetor or fuel injection. The F30 engines give from 80 CV (K-2 version) to 102 CV (ES version).

-All these engines have a displacement of 1042 cc, and are air-cooled, dynamic or forced by two fans, one in each cylinder row.

“F30-A2”

-The F30-E and ES, give different powers but they are very similar. They may have  belt or mechanical reduction gear.

-The F30-E gives 83 CV at 6,000 rpm and the  F30-ES delivers 102 CV at 6,500 rpm.

-The oil is mixed with gasoline. The ratio is from 1 to 80 or 100 and the lubricant additive is usually Bluemax.

“F30-E, ES”

-On the right side we see a part of the G-40 gearbox and on top of the engine the injection system.

“F30-K y U”

-In the picture we see the F30-K that gives 80 CV at 5,500 rpm with carburetors. The U-version also uses carburetors and gives 92 CV at 6,500 rpm.

-At the front we can see the base for a gearbox installation. The turn that has been given to the cylinder heads, attracts our attention.

-The reducer issue deserves to be told. First the toothed belt, which is shown in the below figure.

“Toothed belt reduction gear”

-The gears are adaptable to most of the Hirth engines, as we will see by analyzing the photographs in this chapter.

“G-40 mechanic gear”

“G-40 mounted inverted”

-The F31 returned to two cylinders and 625 cc of displacement.

-The F33 is an upright single-cylinder, with 313 cc or 312 cc depending on the variant.

-They have a power in the order of 25-28 CV. and are built from around 1994 until today.

-The variants are -A-, -B, -AS and -BS. They are very similar to each other.

“F33-B”

“F33 with belt reduction” (PiP)

-The F36 has G-36 belt reduction, and an electric starter. It has a displacement of 208 cc giving 15 CV at 6,000 rpm. So it is smaller than the F33.

-We see a bulky muffler on this single-cylinder, two-stroke engine with a Mikuni diaphragm carburetor.

“F36”

-From the F30 series, some Göbler-Hirth engines were derived for their specialized use on light helicopters. They are those of the "H" series.

-From the F30 we have the H30-ES, also with 1042 cc giving 102 CV at 6,500 rpm. It has forced ventilation of course.

“H30-ES”

-The H32, turns out to be a 2-cylinder in line, giving 61 CV at 6,400 rpm. The fan is located on the side and at the level of the cylinder fins.

-It has a G-50 mechanical gearbox and electric starter. It runs between 5,800 and 6,400 rpm, and has a multipoint injection system.

“H32”

-The H37-E (helicopter version) is the most powerful of its kind. With three in line, 2-stroke, liquid-cooled cylinders it has a displacement of 939 cc, giving 90 CV at 5,200 rpm.

“H37-E”

-The F40 is a boxer again with four horizontally-opposed cylinders and a power of 125 CV.

-At the beginning the 260 series is mentioned. They have been the 260, 261, 262, 263, 273 and 276.

-It has its greatest expression in the 263 (or F263 in the illustration below, installed on a ULM).

-It has 2 upright cylinders and gives 22/25 CV at 3,900/4,000 rpm. It displaces only 383 cc.

-Further it has a Bing carburetor and Bosch ignition. In this installation, it is inclined.

“F263”

-The 276 giving 40 CV at 7,000 rpm has a displacement of 438 cc. This engine has a  Mikuni carburetor and also Bosch ignition.

“276”

We now go to the 2700 series (2701, 2702, 2703, 2704, 2705 and 2706). With and without forced air-cooling. It has two upright cylinders in line.

“2702”

-The powers vary according to the following conditions: According to record, the 2701 displaces 493 cc, and gives 43 CV at 6,800 rpm with Mikuni carburetor and Bosch ignition.

-El 2702 gives 40 CV at 5,500 rpm, displacing 521 cc. The same displacement as the 2703 but with two powers: 52 CV at 6,500 rpm if it has one carburetor and 55 CV at 6,200 rpm if it has two carburetors.

“F2702”

-The 2702 and F2702 of the previous illustrations have a multiple belt reduction placed below the crankshaft. It has a displacement of 521 cc like the F23.

-The 2703 is very similar and has the same displacement of 521 cc, but here it is shown with two carburetors. Both 2701, 2702 and 2703 appeared between 1987 and 1989.

“F2703 with two carburetors”

-As from those dates and until 1994, the 2704, 2705 and 2706 were in production, giving 50, 65 and 70 CV respectively.

“F-2704”

“F-2706”

-The reduction gear that we see on the 2706 is the G-50. We now go to the 3200, 3500 and 3700 series engines.

“3202 and 3203”

-The 3202-E is a high performance and low weight engine. It gives 55 CV at 5,500 rpm, with two in-line cylinders. It has G-50 reduction gear or toothed belt. The 3202-V is very similar. Both have a displacement of 625 cc and as we see, the carburetors are not on the cylinders but on the crankcase, with reed-type valves.

-Below we see the 3501-V from the opposite side with the carburetors. The engine is water cooled, and this series gives 60 CV at 5,000 rpm.

“3501-V”

-The 3500 series continues with a displacement of 625 cc, and a G-50 gearbox. It has Dellorto carburetors with sliding valves. This series is self-lubricating.

“3502-E”

-The 3503-E delivers 70 CV at 6,500 rpm. Like the other ones in the series, starting is done electrically.

-The engines 3701-E and -ES remind us of the H-37, since they are derived from them. The 3701-E gives 80 CV at 4,500 rpm and the 3701-ES gives 100 CV at 6,000 rpm. They use self-lubrication by injection. They have double ignition and are liquid cooled. The displacement increases to 939 cc. The 3702 and 3703 are similar.

“3701-E”

From Appendix A4/6: The F-23 engine is evolving, and now it is available with belt reduction. It weighs 31 Kgs and gives 50 CV at 6,500 rpm.

“A recent F-23”

-Since the completion of the main text until this appendix we have achieved a photograph of a 3002 with 83 CV. It is the successor of the F30 E/K.

“3002”

“New 3503”

-The 3503 that gives 70 CV is offered with carburetors, fuel injection, and optional: heavy oil injection for fuels such as JetA, JP5 or JP8. In the new 3053 HF, carbon pistons are used.

“Carbon piston for the 3053 HF-Heavy Fuel engine”

-Hirth engines that run on kerosene are offered in a wide range, such as the S-1200 HF that has three options: One, two or four cylinders.

-Gobler Hirth offers as an important difference, the use of the new Orbital/Synerject injection system, in which the fuel mixed with air is injected giving a finer pulverization. Both for diesel and gasoline.

“Orbital injector and comparison”

“Orbital system schematics”

“H-30 for helicopter”

-The helicopter engine range includes the H-30, which is a modern version of the F-30.

-The H-32 now has Orbital injection system.

“Orbital logo”

“H-32 HF for helicopter”

“Hirth logo”

-It seems that this is the last logo of the Hirth Motoren brand.

-And a first Göbler-Hirth engine, the RE.028 model, but with double ignition.

“RE-028”

From Appendix 11: A new engine, the 4201, is on Hirth's website. It is a two-cylinder engine with horizontally opposed cylinders. This engine gives 15 CV at 6,500 rpm. It has a displacement of 183 cc and weighs 5.7 kg.

"4201"