The Honda D15B engine, a part of the long string debut engine from the well-recognized D-series of engines, finally made its revolutionary stride in the mid-early 1980s. Though some say that it continued to be eclipsed by its 1.6 L brothers, the Honda D15B has its way of charisma to any enthusiasts out there.
Honda launched the soon-to-be heavyweight D-series lineup to provide a practical and economical approach by providing attitude and swag.
What are Honda D15B Engines?
The production of the Honda D-series engines began in 1984. At that time, the first engine representative was the D15A created for the Honda CRX. Following the production of the D15A is the new installment engine that will eventually stretch throughout the streak of the D15 engine, the Honda D15B engine.
The Honda D15B engine is a 1.5 Liter four-cylinder gasoline engine used in small vehicles such as Honda civic. The Honda D-series engine included D16, D13, D17, D14, and D16. But, of all those mentioned, the D15 takes the cake and is more popular.
Apart from that, the Honda D15B engine came in both single and dual-carbed SOHC versions. The dual carb version is delivering a maximum of 105 PS in the CRX15X. So, when VTEC or Honda’s Variable Valve Timing became available, the two versions of VTEC D15Bs were developed to work for the 1991 – 1995 EG Series.
The one Honda D15B version is the famous VTEC-E delivering approximately 12.5 miles/liter. The other is BTEC D15B, which is more powerful in raw numbers. The Honda VTEC D15B is a breakthrough engine for Honda since it displayed DOHC numbers from a SOHC configuration through the aid of VTEC.
Hence, the VTEC D15B generates 130 PS and redlines at 7,200, replacing the able DOHC ZC design despite having less displacement and one camshaft less.
The most famous application of the D15B was the EG4 and EG8.
Engine Specifications and Design:
- Production Run: 1984 – 2006
- Cylinder Head Material: Aluminum
- Cylinder Block Material: Aluminum
- Configuration: Inline-4
- Bore: 75 mm
- Stroke: 84.5 mm
- Valve-train: SOHC two valves per cylinder, SOHC three valves per cylinder, and SOHC 4 valves per cylinder
- Displacement: 1.5 L (1493 cc)
- Compression Ratio: 8.7, 9.2, 9.1, 9.3, 9.6, and 10.0
- Weight: 250 lbs.
- Max HP: 130 HP at 5,500 – 7,000 RPM
- Max Torque: 102 lb-ft at 3,500 – 5,200 RPM
Honda D15B engine design is an aluminum cylinder block with cast-iron sleeves. There are three-cylinder head types depending on the modification, namely, 8-valve, 12-valve, and 16-valve heads. The latter is most widely used. Further, the engine can either be SOHC or DOHC configuration and includes VTEC technology.
The timing belt drives the camshaft, while the valve-train is solid tappets. Earlier Honda D15B versions used carburetor for the fuel supply controlled by a computer. Then, Honda switched to the single port injection called PGM-CARB, which will, later on, be the new multipoint fuel injection.
There are lots of modifications and upgrades attached to this engine.
The first Honda D15B variant. This release has a compression rating of 9.2, maximum power at 103 HP at 6,800 RPM, 98 lb-ft of torque at 5,200 RPM, and a Twin Carburettor PGM-CARB/fuel injected fuel control system
- 1988 Honda CRX 1.5X
- 1990 Honda Civic 25XXT Formula (JDM)
- Honda Civic Ferio MX EG8 (JDM)
- 1998 – 2001 Honda Capa GA4 (JDM)
- 1988 – 2001 Honda Civic SH4 EF1
Honda D15B VTEC
The Honda D15B civics are the most recognized variants of the Civic range because they have good performance and practicality. And the one that takes the icing on the cake was the VTC D15B version. This variant is also cheaper than the top-ranked SiR. The previous EG-Generation, the Honda VTEC D15B, powered the 3-door EG4 VTi and the 4-door EG8 Ferio VTi.
- 1992 – 1995 Honda Civic VTI (JDM)
- 1992 – 1998 Honda CRX DelSol (JDM)
The Three-Stage VTEC
This variant can hold the crucial title for being the pinnacle development of the D15B engine. Though it has the same configuration as the previous generation VTEC D15B, this version generates the same power at higher RPM with higher torque and compression rating at 9.3.
- 1995 – 1998 Honda Civic Ferio Vi
- 1999 – 200 Honda Civic Vi-RS
- 2001 – 2005 Honda Civic JDM VTEC (JDM and Europe)
This engine is a 92 HP, 88 lb-ft, SOHC 4-valves per cylinder engine. It has a redline of 6,500 RPM and a 7,200 RPM rev limiter. It was produced from 1988 – 1995.
- 1988 – 1991 Honda Civic GL/LX/DX/CX (CX Canadian Market)
- 1992 – 1995 Honda Civic LSi Hatch/Saloon (European Market)
- 1988 – 1991 Honda Civic Wagon Wagovan/DX
- 1992 – 1995 Honda Civic DXi Hatch/Saloon (European Market)
- 1990 – 1995 Honda Concerto (European Market)
- 1988 – 1991 Honda CRX DX
This is a 16-valve engine with a carburetor. The compression rating is 9.2 and produces 106 HP. It was produced from 1988 to 1996.
- 1988 – 1995 Honda Civic Shuttle GL
- 1989 – 1996 Honda Ballade
- 1992 – 1995 Honda Civic LX
- 1988 – 1991 Honda Civic LX/EX
- 1992 – 1995 Honda Civic EX
It is the same as the D15B3 but with two carburetors. It produced 101 HP and was produced from 1989 to 1993. It appears in 1989 – 1993 Honda Civic GL (Australian Market)
The D15B5 engine has new connecting rods, pistons, and cylinder heads. It can be found on the VTEC-E.
This is an 8-valve engine with the same pistons and connecting rods from the D15B1. The compression rating is 9.1 and a 72 HP power. It was produced from 1988 to 1991.
B7 has 103 HP power, and it is the 16-valve version of the D15B6. It was produced from 1992 to 2000.
- 1992 – 1995 Honda Civic GLi (Australian)
- 1993 – 1995 Honda Civic Del Sol S
- 1992 – 1995 Honda Civic DX/LX
- 1998 – 2000 Honda City SX8
- 1992 – 1995 Honda Civic LSi Coupe (European Market)
The D15B8 is an 8-valve engine with the same pistons and connecting rods from D15B1. The compression rating is 9.1.
The Z1 is a 16-valve engine with new pistons and a compression rating of 9.3. This is like a modified VTEC-E and is equipped with a fuel injection system. This engine can be found in 1992 to 1995 Honda Civic VX and Civic VEi.
The analog of D15Z1. It is installed with the new VTEC system firmware.
The Z4 is a 16-valve engine with a modified cylinder head and pistons. This variant can be produced at a maximum of 105 HP and manufactured from 1994 – 2000. This engine appears in Honda Ballade/Civic in South Africa and Venezuela.
The Z6 is the analog of Z4. It has a modified head, is VTEC equipped, and has a 9.6 compression rating and 114 HP. The production is from 1995 to 2000.
The analog of D15Z6 was produced from 1996 to 1999. It has a lean burn system, a modified VTEC and is capable of producing 130 HP.
Engine Tuning, Modifications, and Upgrades
Since the engine already has a D15B head, you will just need to port and polish, buy a cold air intake system, valve springs, cam gear, NGK spark plugs, a 4-2-1 header, Hondata ECU, a 2.5-inch exhaust system, and a 60-mm throttle body.
These modifications will give you about 160 HP. However, you can still get more power, but you need to spend on that, of course.
The Honda D15B engine has fairly strong internals; using them even up to 200 whp with a turbo is still reliable. But, it is still better not to abuse it.
You can buy a turbo kit, or you can build one on the basis of a TD04 turbocharger. With that, you will need a waste-gate, turbo manifold, blow-off valve, a piping kit, 2.5-inch exhaust system, an air/fuel O2 sensor, and a Hondata ECU.
You can also buy a Walbro 255 lph fuel pump, a fuel regulator, an aftermarket fuel rail, and 450 cc fuel injectors.
These upgrades will be enough for the engine to reach 200 WHP.
If you want more power, replace the fuel injectors with a more efficient one, buy H-beam rods, new pistons, and ARP head studs. With all of that, you can increase the boost pressure to the limits and gain up to 280 HP, which is the limit for the TD04.
Try replacing the turbo like the TD05, and get 300 or more HP.
Problems Surrounding Honda D15B Engines:
The Honda D15B engine is special; it truly is. It powered many engines from the Honda arsenal and continues to soar even it was produced decades ago. That’s top-quality right there.
Anyway, with their age, these engines may show signs of deterioration in disguise of some issues. Let’s hear it.
1. Crankshaft Pulley
The first issue we have to deal with here is the crankshaft pulley that often fails. The remedy for this problem is by replacing the crankshaft pulley, others they replace the crankshaft too.
2. Diesel Sound
There’s nothing wrong with sounding like a diesel, though. But for Honda D15Bs, it might be an indication and symptom of a bad exhaust manifold. Inspect the exhaust manifold; there might be a crack.
Unfortunately, that part cannot be welded, so you have to buy a new one.
3. Rough Idling
Not only the Honda D15B has this problem, but most engines have this kind of circumstance. The reasons are different, but the common bottom line is a dirty throttle body or idle control valve.
It can also be in the O2 sensor. Check it or bring it to your trusted specialist.
Some Honda D15B have distributor problems that sometimes fail. When that happens, the engine starts misfiring, losing power, and another problem for the engine. In addition to that, pay more attention to the oil pressure switch sensor and O2 sensors.
In all of what we’ve mentioned above, the Honda D15B engine is excellent overall. Able to prove itself against time, against other competitors, and truly outdone itself. The engine is extremely reliable now wonder some people still look for the EGs and EKs around.
They are icons in their own right as well as a good representation of the JDM car scene.
Honda D15B can last longer than 150,00 miles with the proper oil quality, fuel, maintenance.