Daihatsu A-series engine

The Daihatsu A-series engine is a range of compact two-cylinder internal combustion piston engines, designed by Daihatsu with the aid of their owner Toyota. Petrol-driven, it has cast iron engine blocks and aluminum cylinder heads, which are of a single overhead cam lean burn design with belt-driven camshafts. The head design was called "TGP lean-burn", for "Turbulence Generating Pot".[1] The engine also had twin balancing shafts, which provided smoothness equivalent to that of a traditional four-cylinder engine - although it also cost nearly as much to build.[2]

The engine was developed with some haste in order to replace the two-stroke "ZM" engines used in Daihatsu's earlier Kei cars, and was the first unit to take full advantage of the new 550 cc displacement limit in effect from 1 January 1976. It was first presented in May 1976 as the AB10.[3] Eventually, even a turbocharged version was produced.[4] The engine was replaced by the three-cylinder EB-series in 1985.[5]

AB-series (547 cc)

The AB-series is a 547 cc (0.55 L) version, originally installed in the 1976 Fellow Max 550 but was eventually used in Daihatsu's entire Kei car lineup. Bore is 71.6 mm and stroke is 68 mm. Unlike export versions, Japanese-market engines have a small catalyzer fitted.[6] The engine (AB20) was also installed in the Portuguese Entreposto Sado 550 citycar, of which about 500 were built in the early 1980s.[7] Daihatsu's close competitor, Suzuki, fitted AB10 engines into their Fronte 7-S for a short period, as their own two-stroke engines could not meet increasingly-strict emissions requirements.[8]

Engines designed to be installed in an upright position are denoted AB10, while those intended for a horizontal position (for underfloor usage) are called AB20. The AB55 is a horizontal version equipped with a turbocharger. A downtuned version with 9 PS (6.6 kW) at 2900 rpm and 2.8 kg⋅m (27 N⋅m; 20 lb⋅ft) at 2000 rpm was installed in Toyota's 500 kg (1,100 lb) FG5 forklift from the late 1970s.[9]

Applications:

• 1976.05–1977.06 Daihatsu Fellow Max 550 (L40/L40V)
• 1977.06–1980.06 Daihatsu Max Cuore/Cuore (L45/L40V)
• 1980.06–1985.08 Daihatsu Cuore/Mira (L55/L55V)
• 1976.04–1980.04 Daihatsu Hijet (S40)
• 1977.04–1981.04 Daihatsu Hijet (S60)
• 1982–1984 Sado 550 (Portugal)
• 1977.06–1978 Suzuki Fronte 7-S (SS11)

Name and  layout		Power			Torque				Norm	Comp.	Fuel system	Cat	Fitment	Notes
		PS	kW	at rpm	kgm	Nm	lbft	at rpm
AB-10	4V SOHC	28	21	6000	3.9	38	28	3500	JIS	8.7	carb	●	Fellow Max 550 (L40/L40V),[10] Max Cuore (L45/L40V), Suzuki Fronte 7-S (SS11)
AB-30		29	21		4.0	39	29			9.2		–	Cuore Van (L40V), [Max] Cuore (L40, export) Mira/Mira Cuore (L55V)	Commercials and export models
		26	19		3.8	37	27		DIN[11]
31		23	4.2		41	30	JIS		●			Cuore (L45), Cuore (L55)
AB-31		30	22		4.2	41			30	?		Mira/Mira Cuore (L55V)[4]
AB-??		27	20		4.5	44	33	DIN	9.2	–	Cuore Van (L40V), Mira/Mira Cuore (L55V)	Export version
AB-35		41	30	5.7	56	41	2500	JIS	8.2		turbo	Mira Turbo (L55V)[12]	IHI turbocharger
AB-20		28	21	5500	4.0	39	29		3500		9.2	carb	Hijet 550 (S40), Hijet Wide 550 (S60), Sado 550
		28	21		4.2	41	30						Hijet 550 (S65/66), Hijet Atrai (S65/66), 81.04-82.03
		29	21		4.5	44	33						Hijet 550 (S65/66, 82.04-??)
AB-50		29	21		4.4	43	32				●		Hijet Atrai (S65/66, 82.04-83.09)[13]	horizontally mounted, passenger car emissions
AB-51		29	21	5300	4.5	44	33						Atrai (S65/66, 83.09-86.03)	modified carb, advanced ignition[13]
AB-55	39	29	5500/5300	5.9	58	43	3000			turbo		Atrai Turbo (S65/66, 83.10-86.03)	max power at lower rpm from 1984.02

AD-series (617 cc)

The AD-series is a 617 cc (0.62 L) version of the AB-series engine. Due to its larger size, it does not meet Kei car regulations; it was intended only for export markets. Of Daihatsu products, only the Cuore (often called "Domino" in export markets) was fitted with this engine. Bore is 76 mm and stroke is 68 mm.[12] The only version was an SOHC, two-valve, single carburetted unit. Innocenti also built this engine into their Mini 650, built from November 1984 until November 1987.

See also

• List of Toyota engines

References

1. Yamaguchi, Jack K. (1977), "The Year of the Third Power", World Cars 1977, Pelham, NY: The Automobile Club of Italy/Herald Books: 56–57, ISBN 0-910714-09-6
2. Ferrari, Alessandro (September 1984). "Due cilindri che sembrano quattro" [Two cylinders which feel like four]. Quattroruote (in Italian). Milan, Italy: Editoriale Domus. 29 (347): 71.
3. Baobab Street, Enjoy, p. 130
4. Baobab Street, Enjoy, p. 133
5. Büschi, Hans-Ulrich, ed. (5 March 1987). Automobil Revue 1987 (in German and French). 82. Berne, Switzerland: Hallwag AG. p. 240. ISBN 3-444-00458-3.
6. World Cars 1977. Pelham, NY: The Automobile Club of Italy/Herald Books. 1977. p. 342. ISBN 0-910714-09-6.
7. "O Sado 550" [The Sado 550]. Sado/550: Site não oficial do SADO 550 (in Portuguese).
8. Ozeki, Kazuo (2007). Suzuki Story: Small Cars, Big Ambitions (in Japanese). Tokyo: Miki Press. pp. 66–67. ISBN 978-4-89522-503-8.
9. 自動車ガイドブック [Japanese Motor Vehicles Guide Book] (in Japanese), 25, Japan: Japan Automobile Manufacturers Association, 1978-10-10, p. 291, 0053-780025-3400
10. Costa, André & Georges-Michel Fraichard, ed. (September 1979), Salon 1979: Toutes les Voitures du Monde (in French), Paris: l'Auto Journal, p. 175
11. Daihatsu 550 Sedan: Max Cuore (brochure), Osaka, Japan: Daihatsu Motors, 1978, p. 12, 1103/150/53005
12. Mastrostefano, Raffaele, ed. (1985). Quattroruote: Tutte le Auto del Mondo 1985 (in Italian). Milano: Editoriale Domus S.p.A. p. 234. ISBN 88-7212-012-8.
13. 初代アトレー [First generation Atrai] (in Japanese). アトレークラブ2 [Atrai Club 2]. Retrieved 2012-12-27.

Works cited

Baobab Street (バオバブストリート) (1987). エンジョイ・ダイハツ ミラ, クオーレ/リーザ [Enjoy Daihatsu Mira, Cuore/Leeza]. マイカーエンジョイマニュアル [My Car Enjoy Manual] (in Japanese). Tokyo: Sankaido (山海堂). ISBN 978-4-381-07561-1.