I’m sure honda took the 660 and used it on various other platforms. What other vehicles would the 660 be in? seems like the parts should be easier to find. I’m sure if you just knew what other vehicles this was in, it would be easier to find stuff for it.
Honda Acty wiki will help you, 660cc started with 2nd generation https://en.wikipedia.org/wiki/Honda_Acty 2nd generation: 656 cc E07A SOHC I3 3rd generation: 656 cc E07Z SOHC I3 when you click then on the engines, you find https://en.wikipedia.org/wiki/Honda_E0_engine#E07A E07A Basic specifications Water-cooled 3-cylinder Gasoline Fuel 656 cc (40.0 cu in) total displacement 2 belt drive mechanism of the intake and exhaust valve SOHC 2 Bore & stroke: 66.0 mm × 64.0 mm There were three versions of fuel supply systems for this motor: Carburetor (PGM-CARB), fuel injection (PGM-FI) and MTREC (Multi Throttle Responsive Engine Control). The MTREC version of this engine has the highest power output of the various configurations. E07A (PGM-CARB) SOHC 12 Valve CV carburetor, Displacement: 656 cc, Bore & stroke: 66.0 mm × 64.0 mm, Power: 42 PS (31 kW; 41 hp) / 6,000 rpm, Torque: 5.4 kg⋅m (53 N⋅m; 39 lb⋅ft) / 5,000 rpm Applications: JA2/JA3 Honda Today ,JW3/JW4 Honda Today E07A (PGM-FI) The fuel injected version was standard fitment to the second generation Honda Today (JA4/JA5), which was only available as a passenger car version. The previous generation Today remained on sale and offered a fuel injected engine in some models (XTi, QXi). These earlier versions were tuned for more top-end power than the ones installed in the more comfort-oriented JA4 models. SOHC 12 Valve PGM-FI, Displacement: 656 cc, Bore & stroke: 66.0 mm × 64.0 mm, Power: 52 PS (38 kW; 51 hp) / 7,500 rpm (early), 48 PS (35 kW; 47 hp) / 6,300 rpm (late), Torque: 5.6 kg⋅m (55 N⋅m; 41 lb⋅ft) / 4,500 rpm (early), 5.8 kg⋅m (57 N⋅m; 42 lb⋅ft) / 5,500 rpm (late) Applications: JA2/JA3 Honda Today (first generation) ,JA4/JA5 Honda Today (second generation) E07A (MTREC) In order to extract higher power from a naturally aspirated engine, Honda modified the E07A with a MTREC (Multi Throttle Responsive Engine Control) system, placing individual throttle-bodies on each of the three cylinders. The system modified the air-fuel ratio of individual cylinders based on rpm to give sharper throttle response while also maintaining a stable idle. When fitted to the Today, the engine was tuned for somewhat less peak power in favor of more low-down torque. SOHC 12 valve MTREC, Displacement: 656 cc, Bore & stroke: 66.0 mm × 64.0 mm,Power: 58 PS (43 kW; 57 hp) / 7,300 rpm (Today), 64 PS (47 kW; 63 hp) / 8,100 rpm (Beat), Torque: 6.1 kg⋅m (60 N⋅m; 44 lb⋅ft) / 6,200 rpm (Today), 6.1 kg⋅m (60 N⋅m; 44 lb⋅ft) / 7,000 rpm (Beat) Applications: PP1 Honda Beat , JA4 Honda Today E07Z E07Z PGM-FI SOHC 12 Valve, Displacement: 656 cc, Bore & stroke: 66.0 mm × 64.0 mm, Power: 39 kW (52 hp; 53 PS) / 7,000 rpm, Torque: 6.2 kg⋅m (45 lb⋅ft; 61 N⋅m) / 4,000 rpm (HM2 Honda Vamos), Applications: Honda Acty truck (HA6 / 7), Honda Acty van (HH5 / 6), Honda Vamos / Honda Vamos Hobio (HM1 / 2), Honda Vamos Hobio (commercial grade HJ1 / 2), Honda Life (JB1 / 2), Honda Z (PA1), Honda That's (JD1/2), E07Z (turbo version), PGM-FI SOHC 12 valve turbo, Displacement: 656 cc, Bore & stroke: 66.0 mm × 64.0 mm, Power: 47 kW (63 hp; 64 PS) / 6,000 rpm, Torque: 9.5 kg⋅m (69 lb⋅ft; 93 N⋅m) / 3,700 rpm (HM1 Vamos) Applications: Honda Vamos / Vamos Hobio (HM1 / 2), Honda Life Dunk (JB3 / 4), Honda Z (PA1), Honda That's (JD1/2), ECA1 The ECA1 engine was used in the first-generation Honda Insight, as part of the car's Integrated Motor Assist gasoline-electric hybrid drive system. A three-cylinder engine, it displaces 995 cc and features a SOHC 12-valve head. The engine is supplemented in various circumstances by a 10 kW permanent magnet DC electric motor adding 9.7 kW (13.0 hp; 13.2 PS) and 2.2 kg⋅m (16 lb⋅ft; 22 N⋅m) torque throughout the entire RPM range. SOHC 12 valve VTEC PGM-FI, Displacement: 995 cc, Bore & stroke: 72.0 mm × 81.5 mm, Compression ratio: 10.8:1, Power: 50 kW (67 hp; 68 PS) / 54 kW (72 hp; 73 PS) (with IMA) @ 5,700 rpm, Torque: 9.4 kg⋅m (68 lb⋅ft; 92 N⋅m) / 4,800 rpm & 12.6 kg⋅m (91 lb⋅ft; 124 N⋅m) / 2000 rpm (with IMA) (ZE1 Honda Insight)[1] Applications: 2000-2006 Honda Insight