Honda F20B/F20C engine characteristics
Parameter | Value |
---|---|
Manufacturing | Honda Motor Company |
Engine make | F20 |
Years of manufacture | 1989-2009 |
Cylinder block material | aluminum |
Power system | injector |
Type | row |
Number of cylinders | 4 |
Valves per cylinder | 4 |
Piston stroke, mm | 88, 84 (F20C) |
Cylinder diameter, mm | 85, 87 (F20C) |
Compression ratio | 9.0, 9.5, 11.0, 11.7 |
Engine displacement, cc | 1997, 1998 (F20C) |
Engine power, hp/rpm | 90/6000, 110/5700, 110/5700, 115/5300, 131/5400, 133/6000, 133/5300, 133/5600, 136/5600, 152/6100, 180/7000, 200/7200, 240/8300, 250/8300 |
Torque, Nm/rpm | 150/3500, 150/3500, 150/3800, 172/4200, 178/4800, 179/3700, 179/5000, 180/4400, 184/4500, 186/5000, 192/5500, 197/6400, 208/7500, 218/7500 |
Fuel | 95-98 |
Environmental regulations | – |
Engine weight, kg | 150 (F20B) |
Fuel consumption, l/100 km | – city: 10.7, – highway: 6.8, – mixed: 8.6 |
Oil consumption, gr./1000 km | to 500 |
Engine oil | 5W-20, 5W-30, 5W-40, 10W-30, 10W-40, 10W-50, 15W-40, 15W-50, 20W-20, 0W-40 (S2000), 5W-30 (S2000), 5W-40 (S2000), 5W-50 (S2000), 10W-30 (S2000), 10W-40 (S2000) |
How much oil in the engine, liters | 3.8, 4.8 (S2000) |
Oil change is carried out, km | 10000 (better 5000) |
The operating temperature of the engine, deg. | 90-95 |
Engine life, thousand kilometers | – according to the factory data: -, in practice: 300+ |
Tuning | – potential: 600+ (S2000), – without loss of resource: – |
Motor installed | Honda Accord, Honda Prelude, Honda S2000, Honda Torneo, Honda Ascot Innova, Rover 620i |
Honda F20 engine troubleshooting and repair
The F20 was launched in September 1989 and first appeared on the Ascot and Accord. This engine used an aluminum cylinder block similar to other F motors, with a height of 219.5 mm. The engine has an open cylinder block, with an 88 mm stroke crankshaft and balance shafts. The connecting rods are 145 mm long, the pistons are 85 mm in diameter and their compression height is 31 mm. Out of all this, Honda got 2 liters of displacement.
The F20 head is single camshaft SOHC, but 16 valve. The VTEC system is not used, in the vast majority of cases. There are also versions with DOHC head. The diameter of the inlet valves is 34 mm, the exhaust valves 29 mm. Timing drive on F20 is belt drive, belt replacement is required every 90 thousand kilometers. If the belt breaks, the F20B will not bend valves, but if it broke in VTEC mode, it will bend valves. Also bends valves F20A.
On this motor it is necessary to adjust valves every 40-50 thousand kilometers. Valve clearances on a cold engine: intake 0.24-0.28 mm, exhaust 0.28-0.32 mm.
Among many modifications of ordinary F20 motors, which we have described below, there is a very interesting and extremely unusual motor – F20C. Despite the presence of the letter F in the designation, this engine is structurally closer to K20A motors.
It is a sports engine developed almost from scratch, specifically for the Honda S2000, and was put into production in 1999. It uses an aluminum cylinder block, but with increased cylinder bore to 87 mm, the cylinder walls are made of FRM material, and the block height is 224 mm. The pistons are forged, with a compression height of 29mm and a compression ratio of 11.7 for JDM and 11.0 for the rest of the world, and it also uses its own lightweight connecting rods, 153mm long. A crankshaft with a shorter piston stroke of 84mm has been fitted inside the block. Thanks to this it was possible to make the motor short-stroke, reduce vibrations and do without balancer shafts, as well as to keep the working volume of 2.0 liter.
The F20C head, of course, is its own, it has excellent blow-by, much better than the F20B. This cylinder head has revised intake and exhaust ports, larger valves (36mm intake, 31mm exhaust), aggressive camshafts with 300/298 phase and 12.65/11.66mm lift, and stiff valve springs.
Unlike the F20B, the timing on the F20C is chain-driven.
This motor uses its own intake manifold, a lightweight flywheel (6.5 kg) and a 4-2-1 stainless steel exhaust manifold. The performance of the standard F20C engine injectors is 360 cc. Throttle diameter is 62.5 mm.
Compared to the F20B, the F20C engine weighs 8 lbs less and has slightly smaller dimensions.
Thanks to all of the above, as well as a number of other details, this 2-liter motor, in JDM version, develops 250 hp at 8300 rpm and spins to a cutoff of 8900 rpm. Without the use of supercharging systems, Honda engineers removed 125 hp per liter of displacement, which was a record until 2009, then slightly surpassed by the Ferrari 458 Italia.
For the rest of the world, the S2000’s output was reduced to 240 hp at 8300 rpm.
The F20 engine was part of the F-motor family and had a number of counterparts with a different displacement: the F18, F22 and F23. And also, in parallel with F-motors was produced and related sporty H series (H22 and H23), which is very and very technically close.
The engine Honda F20 was produced until 2001, after which it was removed from production and began to produce the well-known K20A. The sporty version F20C was delayed for a longer time – until 2009. Since 2003, the 2.2-liter F22C was produced on the basis of F20C.
Modifications of the Honda F20 engine
- F20A – motor with a twin-shaft cylinder head. Power output is 152 hp at 6100 rpm, torque 186 Nm at 5000 rpm. The engine is found on Accord and Prelude.
- F20A2/F20A3/F20A6 is the SOHC version with a SOHC cylinder head and carburetor for the Honda Accord. Its motor output is 110 hp at 5700 rpm and 150 Nm of torque at 3500 rpm. For the F20A6, it is 90 hp at 6000 rpm, 150 Nm of torque at 3500 rpm.
- F20A4/F20A5/F20A7/F20A8 – analog of F20A2, but in injector version for Honda Accord and Prelude cars for different countries. Power 133 hp at 5600 rpm, torque 180 Nm at 4400 rpm.
- F20B is the smaller counterpart of the H22A, its head is similar to the H22A4 with camshafts from the Type S and is equipped with a VTEC system. The compression ratio is 11 and the throttle is 62.5mm. The F20B was used in the Honda Accord for the Japanese market and the Honda Torneo. Power characteristics of the F20B are significantly higher than conventional F20A, because it develops 200 hp at 7200 rpm and 197 Nm of torque at 6400 rpm.
The F20B engine has a variation with simplified camshafts from the JDM H22A Black top, with a 60 mm flap, which was used on cars with automatic transmission, producing 180 hp at 7000 rpm and 192 Nm of torque at 5500 rpm. - F20B3 – F20A analog with multi-point fuel injection for the European market.
- F20B6 – analog of F20B3, but its block is covered with a single-shaft cylinder-head with VTEC.
- F20C is a sport motor for S2000. It is described at the beginning of the article.
- F20Z1 – analog of single-shaft F20A for Europe.
- F20Z2 – analog of F20Z1 with pistons with compression ratio lowered to 9, with other camshafts and firmware.
Problems and disadvantages of Honda F20B/F20C engines
The F20A/F20Z and F20B motors are technically very similar to the H22A and H23A, and their problems are also the same. You can learn more about them here.
Also, on the F20B, the revs may start to float due to the COC.
The S2000 engine is much different and has its own problems:
- Transmission timing chain tensioner problem. Extraneous noise at startup and at idle indicates the need for its replacement. Usually it happens after 100-150 thousand kilometers, but can come and earlier
- Retainer problem. Due to oil starvation or too high revolutions, there can be destruction of retainers, which leads to dire consequences (buying a new engine). It is better to replace them together with dryers with refined ones from restyled S2000 (after 2003).
- Oil burn. It is common for these motors and can be up to 1 liter per 1000 km. Most likely you need to change the oil caps and rings, but the exact diagnosis will be made at autopsy.
For the F20C engine is very important to use quality oil and change it in time, then you will be able to delay the appearance of many problems. The resource of Honda S2000 engine is quite high, as for a high-force atmospheric and can pass over 200 thousand kilometers, if you maintain it in time and use quality working fluids.
Honda F20B/F20C engine tuning
Atmospheric
F20B tuning can be started by installing an H22A head and all the attachments from this motor. It will give the effect, but too much fiddling, and the result will still be worse than on the 2.2 liter motor. But if you want, then do it. Further tuning of the head is similar to modification of H22A.
To refine single-shaft motors is time and money in the wind, make a swap to a more powerful motor or to another car.
For the F20C engine you can do the usual cold intake + straight exhaust + tuning. This will give about 10hp.
If this is not enough, and this is not enough, then you need to do porting of the cylinder head with the installation of bronze guides, stiff springs, tuning valves (+1 mm intake and stock size exhaust), titanium plates. Put a 50mm throttle on the intake, a 4-2-1 spider on the exhaust with a 76mm exhaust. You will need evil camshafts, cut gears, pistons under compression ratio ~14, injectors performance in the neighborhood of 550 cc, light flywheel, brain AEM EMS and sport fuel. This will produce over 300hp at the flywheel.
To get close to 300hp at the wheels you need as much porting as possible, a 2.2 liter stroker kit with a 90.7mm crankshaft from the F22C and connecting rods from the same.
F20C Turbo
To get 300 without much trouble, you just need to buy a compressor kit to put on a stock bottom end. For 400+ hp you need a turbine and you can also blow into the stock motor, with good tuning it holds even 600-700 hp, but the head is better to refine and replace the valves with plates on tuning. For supercharging it is suitable turbo kit based on Garrett GT3071R or similar turbine. This is enough to get sub 500hp at the flywheel on water-methanol.
F20B / F20C ENGINE RATING: 4 / 5