Onex build log: VW engines

VW engines has been used to power light aircraft since the second world war. It all started in France according to a very interesting webinar by John Monnett about the AeroVee engine. All in all the VW engine as an aircraft engine is a very interesting topic, but real historical info is hard to find. User experience of these engines is also hard to find, usually just net-gossip by people who have never used one. I am used to Lycoming, Continental, Rotax and a couple of hours with Jabiru, I have never flown an aircraft with a VW engine. Below are some simple comparisons of various available engines to at least get some perspective about some of the basic data for these engines.

VW engine types

VW made at least 3 major flat 4 engines, or boxer engines. I don't know what their real names are, but the popular naming is Type 1, Type 4 and Wasserboxer (Water boxer). All these engines are used as aircraft engines.

Type 1

The Type 1 is the original beetle engine. They were made with a capacity of 1100 to 1600 cc. This is the engine most commonly used today in aircraft. The crankcase is made of magnesium. Aircraft engines typically have a capacity of 1600 to 2400 cc and a power of 50 to 90 HP.

Type 4

The type 4 was a new development of the air cooled boxer concept. The engine is larger and heavier and originally made for the VW 411 and 412 (we had a 411 when I was a little boy). It was also used in some VW vans and in the Porsche 914. The original capacity was 1700 to 2000 cc. I know of only one commercial conversion of this engine, the Grob 2500 used in the Grob 109b motorglider.

Wasserboxer

The wasserboxer was a development of the Type 1 engine. It was used in VW vans and came after the Type 4. Sauer and Limbach supposedly use the crankcase of this engine for their larger engines, but it seems to be a custom made case based on the wasserboxer rather than an actual VW crankcase. The crankcase is made of aluminium and is considerably stronger built than the Type 1, yet only about 7 kg heavier and roughly the same size. It was designed for 1900 and 2100 cc. Aircraft engines using this crankcase have a capacity of 2000 to 2700 cc.

Engines

The AeroVee is the engine for which the Onex is designed around. It looks like a fairly simple straight forward engine. It comes as a kit. Type 1. USA

Pro: Have been developed over many years (30-40 years) by people who actively use this engine themselves in many airplanes (Sonex Aircraft). The Onex is designed around it. A Turbo will soon be available, 100 HP.

Great Plains have several engine kits from 1600 to 2300 cc. They are straight forward engines. Type 1. USA

Pro: I don't know, but the company seems to be well liked. Some like the Hub with its larger #4 bearing.

The Grob 2500. This is the Type 4 engine, and one can see the different intake and exhaust manifolds compared with Type 1. This engine is no longer available. Germany

The Hummel engines looks to be very similar to the GP engines. The capacity is 1600 to 2400 cc.

Pro: Don't know, but they shop hubs from GP. Type 1. USA

JPX delivered very advanced engines, at least by the looks of it. They are no longer in business, but countless Jodels are flying with JPX engines. The capacity was 2000-2500 cc. Type 1 and some custom I think. France

Limbach has sold over 6000 engines, and represent the most advanced VW engines ever produced. They make engines from 1700 to 2400 cc. This one is a 2400 DFi with water cooled heads, fuel injection and electronic ignition. Type 1 and Wasserboxer. Germany

Pro: The most advanced VW engine money can buy.

The Motorav engine looks like a very modified engine. It's from Brasil and availability is unknown. Custom casing. Brasil

The Revmaster R-2300 looks like a thought through engine. More customized than the other engines from the USA. Type 1. USA

Pro: Simply looks like a very good engine

The Revmaster R-3000 is not yet available. It is all custom parts. USA

Sauer also delivers very advanced engines. They are very light and powerful. This one is the 2100 ULT (turbo). Sauer has sold more than 750 engines from 1800 to 2700 cc. Sauer engines are often used as drop in replacement engines for older Limbach engines in motorgliders. Type 1 and Wasserboxer. Germany

Pro: Light, powerful and high quality. 1600 h TBO

Data

Engine	Max HP	at RPM	Cont, HP	at RPM	Weight (kg)	Crankcase	Cooling	Bore (mm)	Stroke (mm)	cc
AeroVee 2.1	80	3400	80	3400	73	Type 1	Air	92	82	2180
GP 1600	55	3600	50	3400	72	Type 1	Air	85.5	69	1585
GP 1835	65	3600	60	3400	74	Type 1	Air	92	69	1835
GP 1915	69	3600	65	3400	74	Type 1	Air	94	69	1915
GP 2180	76	3600	70	3400	75	Type 1	Air	92	82	2180
GP 2276	80	3600	76	3400	75	Type 1	Air	94	82	2276
Grob 2500	95	3400	87	3000	95	Type 4	Air	100	78	2450
Hu 50 HP	55	3600	50	3400	73	Type 1	Air	85.5	69	1585
Hu 60 HP	65	3600	60	3400	75	Type 1	Air	92	69	1835
Hu 76 HP	76	3600	70	3400	76	Type 1	Air	92	82	2180
Hu 85 HP	85	3600	80	3400	76	Type 1	Air	94	86	2387
JPX 4T60	65	3200	61	3100	72	Type 1	Air	93	75.4	2049
JPX 4TX75	82	3000	76	2900	78	JPX	Air	95	82	2325
JPX 4TX90	90	3000	82	2900	74	JPX	Air	95	88	2495
L 1700 E0	68	3600	60	3200	73	Type 1	Air	88	69	1679
L 2000 E0	80	3400	70	3000	74	Type 1	Air	90	78.4	1995
L 2000 EB	80	3400	70	3000	76.5	Wasserboxer	Air	90	78.4	1995
L 2400 EB	87	3200	84.5	3000	82	Wasserboxer	Air	97	82	2424
L 2400 DFi	100	3000	95	2800	76	Wasserboxer	Water	97	82	2424
L 2400 DT	129	3000	118	2700	86	Wasserboxer	Water	97	82	2424
L 2400 DT.X	158	3000	145	2700	86	Wasserboxer	Water	97	82	2424
M 2.4 R	85	2900	80	2700	85	Motorav	Air	94	88	2443
M 2.6 R	90	2900	85	2700	86	Motorav	Air	94	94	2609
M 2.8 R	100	2900	95	2700	84	Motorav	Air	98	94	2836
R-2300	85	3200	80	3000	77	Type 1	Air	94	84	2332
R-3000	115	3400	110	3200	93	Revmaster	Air	102.4	90	2965
S 1800 UL	68	3200	65	3000	63	Type 1	Air	92	69	1835
S 1900 UL	75	3200	72	3000	64	Type 1	Air	94	69	1915
S 2200 UL	85	3000	80	2700	66	Type 1	Air	92	84	2234
S 2400 UL Al	90	3000	80	2700	75	Wasserboxer	Air	94	84	2332
S 2400 UL Mg	90	3000	80	2700	68	Type 1	Air	94	84	2332
S 2100 ULT	110	3000	100	2800	76	Wasserboxer	Air	90.5	84	2161
S 2500	94	3000	82	2700	77	Wasserboxer	Air	97	84	2483
S 2700 UL	105	3000	93	2700	75	Wasserboxer	Air	97	90	2660

GP = Great Plains, Hu = Hummel, L = Limbach, M = Motorav, R = Revmaster and S = Sauer. Grey are not longer available and green is not yet available.

Bore and Stroke

	Stroke[mm]
Bore [mm]	69	75,4	78	78.4	82	84	86	88	90	94
85.5	1.24 GP1600 Hu1600
88	1.28 L1700
90	1.30 S1800			1.15 L2000		1.07 S2100 S2100UL
90.5						1.08 S2100ULT
92	1.33 S1800UL GP1835 Hu1835				1.12 AeroVee GP2180 Hu2180	1.10 S2200UL
93		1.23 JPX4T60
94	1.36 S1900UL GP1915				1.15 GP2276	1.12 S2400UL R-2300	1.09 Hu2400	1.07 M2.4R		1.00 M2.6R
95					1.16 JPX4TX75			1.08 JPX4TX90
97					1.18 L2400	1.15 S2500 S2500UL S2500ULT			1.08 S2700UL
98										1.04 M2.8R
100			1.33 Grob2500
102.4									1.14 R-3000

Here the Bore is along the Y axis and Stroke along the X axis. The bore/stroke ratio is plotted in along with the engines. I don't know exactly what to make of this, but it gives a nice overview of the engines.

Crankcase

	Stroke[mm]
Bore [mm]	69	75,4	78	78.4	82	84	86	88	90	94
85.5	1585 Type1
88	1679 Type1
90	1756 Type1			1995 Type1 WB		2138 Type1
90.5						2161 WB
92	1835 Type1				2180 Type1	2235 Type1
93		2049 Type1
94	1915 Type1				2276 Type1	2332 Type1 WB	2387 Type1	2443 Motorav		2609 Motorav
95					2325 JPX			2495 JPX
97					2424 WB	2483 WB			2660 WB
98										2836 Motorav
100			2450 Type4
102.4									2965 Revmaster

Different crankcase and displacement are plotted in this table. The largest Type 1 is the Hummel with 94 bore and 86 stroke. The largest Wasserboxer is the Sauer with 97 bore and 90 stroke

Onex build log

VW engines