Honda H23A engine
|Manufacturer||Honda Motor Company
|Also called||Honda H23
|Cylinder block alloy||Aluminum|
4 valves per cylinder
|Piston stroke, mm (inch)||95 (3.74)|
|Cylinder bore, mm (inch)||87 (3.43)|
|Displacement||2258 cc (138.8 cu in)|
|Power output||118 kW (160 HP) at 5,800 rpm
121 kW (165 HP) at 5,800 rpm
140 kW (190 HP) at 6,800 rpm
147 kW (200 HP) at 6,800 rpm
|Torque output||209 Nm (154 lb·ft) at 4,500 rpm
212 Nm (156 lb·ft) at 4,500 rpm
221 Nm (163 lb·ft) at 5,300 rpm
221 Nm (163 lb·ft) at 5,300 rpm
|HP per liter||70.9
|Weight, kg (lbs)||220 (485) – H23A VTEC
|Fuel consumption, L/100 km (mpg)
|Turbocharger|| Naturally aspirated
|Oil consumption , L/1000 km
(qt. per miles)
|up to 0.5
(1 qt. per 1200 miles)
|Recommended engine oil||5W-30
|Engine oil capacity, L (qt.)||4.3 (4.5)
|Oil change interval, km (miles)||5,000-10,000
|Normal engine operating temperature, °C (F)||–|
|Engine lifespan, km (miles)
-No life span loss
|The engine is installed in||Honda Accord
Honda Ascot Innova
Along with the 2.2-liter H22A, a 2.3-liter H23A was made, which in fact was a stroker version. This engine was fitted with almost the same 219.5 mm high aluminum engine block with FRM coated cylinder walls.
Let us look at the main differences between engines H23A and H22A. To obtain 2.3 liter of displacement, they inserted a 95 mm stroke crankshaft and pistons with the compression height of 30.5 mm; the rod length was decreased to 141.5 mm. All together, it provided the displacement of 2,259 cc.
Cylinder head H23A has a typical DOHC design: two cams and 4 valves per cylinder. However, it does not have the variable valve timing and lift electronic control system VTEC. Therefore, H23A engines lost power and aggression.
The diameter of the JDM H23A intake valves is 35 mm, of the exhaust valves – 30 mm. In the versions for USDM and EDM, 34 mm inlet valves and 29 mm exhaust valves were used.
After every 25,000-30,000 miles, valves are to be adjusted. The valve clearances for a cold engine are as follows: intake – 0.07-0.11 mm, exhaust – 0.15-0.19 mm.
These engines were fitted with 240 cc fuel injectors. Throttle body diameter was 60 mm, same as in H22A.
The H23A firing order is: 1-3-4-2.
Together with the H-series, Honda also made the technically similar F-series of engines, which included models F18, F20, F20C, F22, F22C and F23.
The H23A engine was manufactured until 2002, when it was replaced by K24A.
Honda H23A engine modifications and differences
1. H23A – there are two versions of the JDM H23A:
– H23A Black top – the standard version with open deck block. These engines were installed in JDM Ascot Innova.
– H23A VTEC Blue top – the top version with the VTEC system. Its main difference was a PDE head, which was very close to the H22A Euro R head. They also increased the compression ratio to 10.6; the Euro R throttle body and 295 cc/min fuel injectors were used here. The H23A VTEC engine was installed in JDM Honda Accord Wagon AWD, where it reached 190 HP @ 6,800 rpm, and the torque of 221 Nm at 5,300 rpm. The same motor was installed in JDM Accord Wagon SiR, but its power was boosted to 200 HP @ 6,800 rpm with the torque of 221 Nm @ 5,300 rpm. On H23A VTEC, the redline was set to 7,200 rpm.
2. H23A1 Black top was the version for North America. Main question is: Does H23A1 have VTEC? No, unfortunately, it is an ordinary engine. The engine power is 162 HP @ 5800 rpm, the torque is 212 Nm @ 4500 rpm. This engine was installed in Honda Prelude 4th gen.
3. H23A2 Black top was the European version of the H23A1 engine for Honda Prelude 4th gen.
4. H23A3 non-VTEC was the version of H23A2 for European Honda Accord and Rover 623. Its valve cover is black, so it was called Black Top.
Honda H23A engine problems and malfunctions
The main problems and disadvantages of this engines are the same as for the H22A engine. HERE you will learn more about it.
The easiest performance tuning of H23A is buying an aftermarket intake manifold, 4-2-1 headers and an 2.5 inch exhaust system. But it is better to use a H22A Euro R intake system. These mods will add up about 20 HP That’s not enough? Then buy Skunk2 Pro1 cams, valve springs and adjustable cam gears. It will approximately add extra 10 HP. Getting more power is very difficult without port and polish; you have to do it if you want to go even faster. Then buy Skunk2 Pro2 cams, and get over 250 horsepower. This is the limit that is not worth exceeding, it would be less expensive to simply buy a faster car.
Let’s start easy, H23A stock internals cannot withstand more than 300 horsepower, they have pretty weak rods. You can install an inexpensive turbo kit and get more power, but use it at your own risk.
Building a good turbo project will be much more expensive, but we will tell you how to do it. To start, you will need H23A sleeves for your engine block to withstand a lot of power. Of course, stock internals should be replaced with forged pistons and H-beam rods (e.g., Eagle). You will also need ARP studs, a Garrett T04e turbocharger, a turbo manifold, an intercooler, HKS BOV, a Walbro 255 lph fuel pump, a 3-row radiator, an aftermarket fuel rail, 680 cc fuel injectors, an aftermarket fuel regulator, a wideband air/fuel oxygen sensor, the 3″ performance exhaust system, and a Hondata ECU. You will also have to make an oil feed line for the turbocharger. It would be great if you make head porting, and replace valves, valve springs and valve guides.
After ECU tuning, with the boost pressure of about 15 PSI (1 bar), you can reach over 350 horsepower.