Honda B16 vs B18 Engine Guide

Arguably one of the most popular 4-cylinder engine families of all time, the Honda B-Series is a staple of the classic Honda catalog, featured in cars like the Honda/Acura Integra Type R, EK9 Civic Type R, and Acura Integra GS-R. Honda’s ability to design fantastic engines has been a staple of the company for decades. Honda’s B-series launched their 4-cylinder, low displacement, high revving, DOHC, VTEC formula to superstardom. Over the B-series’ 12-year run between 1989 and 2001, it exemplified quality engineering on a budget. So much so that the B-series is still celebrated and praised to this day. 

The Honda B-series has 6 variants in total, each with their own subvariants, characteristics, and vehicle applications. That’s pretty insane. Within those variants, the B-series has two distinct short blocks that share the same design, but have different deck heights. The B16 has a shorter deck height of 8.03 inches while the B18 block has a deck height of 8.3 inches. The discrepancy in deck height results in a difference in displacement between the B16 and B18. Since the stroke of the B18 was increased significantly over the B16, the two have different performance characteristics and vehicle applications.

In this article, we’ll cover the similarities and differences between Honda B16 vs B18 engines. 

Honda B-Series Engine History

The Honda B-series is a group of 4-cylinder engines designed by Honda to replace the SOHC D-series. By the time 1986 rolled around, single overhead cam engines were starting to become truly antiquated. The Honda B-Series engine not only introduced a dual overhead cam valvetrain to the Honda 4-cylinder formula, but also introduced Honda’s variable valve timing system, known as VTEC, to Honda’s B16 engine offerings too. 

Obviously, VTEC would go on to be a defining characteristic of most Honda 4-cylinders to follow in the future. Like the D-Series 4-cylinder that preceded it, the B-Series featured a counter-clockwise-rotation engine orientation.

The Honda B18 engine series was released a few years after the Honda 1.6L B16 engines in 1990. While there was an earlier B18A engine released in Japan in 1986, it is not regarded as part of the modern Honda B18 engine series, as it was a dual-carburated engine. Unlike the 1.6L B16, the majority of Honda’s 1.8L B18 engines lacked VTEC. They also featured a longer deck height and lower compression than the B16 engine. The B18’s undersquare design favored low-RPM performance, with most of the power and torque being produced down low. 

The Honda B-Series engine has cemented itself in the JDM aftermarket scene as one of the most modifiable Japanese 4-cylinders ever made. One of the reasons that they are so popular in the aftermarket community is their reliability, having very few common problems. With the right modifications, there are B-Series engines out there edging close to the 1,000 horsepower mark. 

If you are interested in learning more about the Honda B16 or Honda B18 engines separately, check out our Honda B16 Engine Guide and our Honda B18 Engine Guide!

Honda B16 Engine Specifications

Engine	Honda B16
Configuration	Inline-4 Cylinder
Displacement	1.6L (1,595 cc)
Aspiration	Naturally Aspirated
Valvetrain	DOHC w/ VTEC
Block/Head	Aluminum/Aluminum
Bore x Stroke	81 mm × 77.4 mm (3.19 in × 3.05 in)
Compression Ratio	10.2:1 – 10.8:1
Weight	Long Block ≈ 306 lbs – 395 lbs
Horsepower	150-182 hp @ 7,400 – 8,200 RPM
Torque (lb-ft)	111-118 lb-ft @ 6,300 – 7,500 RPM
VTEC Engagement	5,200 – 6,100 RPM

The B16 (1.6L) engine family has eight different variants, offered between 1988 and 2001. Honda B16 variants include the first-gen B16A, second-gen B16A, B16B, B16A1, B16A2, B16A3, B16A5, and B16A6. All B16 variants share very similar engine construction, retaining 1.6L of displacement, the same stroke and bore, and DOHC valvetrain. All engines in the B16 family have aluminum head and block construction and feature strong factory internals. 

Despite their fundamental similarities, each B16 variant was designed for its own vehicle application and differs slightly from the next. All engines in the Honda B16 lineup have a DOHC valvetrain with some form of i-VTEC variable valve timing. In fact, the Honda B16 was the first engine to introduce VTEC to the world in the B16A. 

Honda B16 Variant Differences

Outside of variable valve timing differences, the B16 variants differ in a number of other ways. The compression ratios between variants vary by a significant amount. For example, the highly sought-after JDM B16B engine from the JDM 1997-2000 Civic Type-R has an extremely high 10.8:1 compression ratio. In contrast, the B16A, B16A1, B16A2, B16A3, and B16A6 have a much lower 10.2:1 compression ratio. This is due to the B16B’s increased deck height and longer rods among other differences.

The Honda B16 has the smallest displacement of the entire B-Series platform. With only 1.6L of displacement, it is outsized by the Honda B17 engine with a displacement of 1.7L, the Honda B18 engine with a displacement of 1.8L, and the Honda B20 engine with, you guessed it, 2.0L of displacement.

Honda B16 Engine Applications

First Generation B16A

• 1989-1993 Honda Integra XSi
• 1989-1991 Honda CRX SiR (EF8)
• 1989-1991 Honda Civic SiR (EF9)

Second Generation B16A

• 1992–1993 Honda Integra “XSi” (DA6, DA8)
• 1992–1994 Honda Civic SiR/SiRII (EG6)
• 1992–1993 Honda Civic Ferio SiR (EG9)
• 1992–1995 Honda CR-X del Sol SiR (EG2)
• 1996–1998 Honda Civic SiR/SiRII (EK4)
• 1996–2000 Honda Civic Ferio SiR (EK4)

B16B

• 1997–2000 Civic Type R

B16A1

• CRX’1.6 DOHC VTEC (EE8) – European market (EDM)
• Civic’1.6 DOHC VTEC (EE9) – European market (EDM)

B16A2

• 1992-2000 Honda Civic EDM VTi (EG6/EG9 & EK4)
• 1992-1997 Honda Civic del Sol EDM VTi (EG)
• 1996-1997 Honda Civic del Sol VTEC USDM (EG2)
• 1996-1998 Honda Civic AUDM & NZDM Vti-R (EK4)
• 1999-2000 Honda Civic AUDM Vti-R (EM1)
• 1999-2000 Honda Civic USDM Si (EM1)
• 1999-2000 Honda Civic SiR Philippines (EK4 Sedan)
• 1999-2000 Honda Civic CDM SiR (EM1)

B16A3

• 1994-1995 Del Sol VTEC USDM VERSION

B16A5

• 1996-2000 Civic Si-RII (JDM version) (EK4)

B16A6

• 1996–2000 Honda Civic – Middle East & South Africa VTEC (SO3, SO4)

Honda B18 Engine Specifications

Engine	Honda B18
Configuration	Inline-4 Cylinder
Displacement	1.8L (1,797 – 1,834 cc)
Aspiration	Naturally Aspirated
Valvetrain	DOHC (Some With VTEC)
Block/Head	Aluminum/Aluminum
Bore x Stroke	81 mm × 89 mm (3.19 in × 3.50 in)
Compression Ratio	9.2:1 – 11.1:1
Weight	Long Block ≈ 395 lbs
Horsepower	130-197 bhp @ 6,000-8,000 RPM
Torque (lb-ft)	121-133  lb-ft @ 5,000 – 7,500 RPM

The Honda B18 engine family was offered in a whopping 16 different variants, with the US only receiving 6 of them. The US-Spec Honda B18 variants include the B18A1, B18A2, B18B1, B18B2, B18C1, and B18C5. Overall, the Honda B18 engine similar to the B16 in terms of its arrangement and construction. However, the two engine families differ in multiple important ways too. The B18 features a completely different bottom end, including a different stroke, rod lengths, deck height, pistons, and rods. 

Ultimately, these differences result in an increased displacement for the B18 at 1.8L. In addition to the bottom-end differences and increased displacement, most B18 variants also lack VTEC variable valve timing. Despite its lack of VTEC, one of the B18’s primary selling points is its strong torque figures. Even the least powerful B18A1 produced 121 lb-ft of torque. The most powerful US B18C5 produced 130 lb-ft at 7,500 RPM, making it a good engine for racing. 

While we didn’t receive the most powerful B18 variant stateside, we did receive a number of very capable B18 variants in the United States. The most powerful B18 variant is the JDM B18C Type-R, found in the DC2 and DB8 Honda Integra Type-Rs, producing 197 horsepower and 133 lb-ft of torque. The most powerful B18 variant that we received stateside is the Honda B18C5. The B18C5, out of the 2000-2001 Acura Integra Type-R, produces 195 horsepower and 130 lb-ft of torque.

B18 Engine Applications

First Generation B18A

• 1986–1989 Accord Aerodeck LXR-S/LX-S (Japan)
• 1986–1989 Accord EXL-S/EX-S (Japan)
• 1986–1989 Vigor MXL-S (Japan)

B18A1

• 1990–1991 Acura Integra USDM “RS/LS/LS Special Edition/GS” (DA9 Liftback/Hatchback, DB1 Sedan)
• 1992-1993 Acura Integra USDM “GS/LS/LS Special Edition/RS” (DA9 Liftback/Hatchback, DB1 Sedan)

B18A2

• 1990-1993 Honda Integra LS DB1 Sedan

B18B1

• 94-01 Integra RS/LS/SE/GS – DB7/DC4/DC3
• 1994–2000 Honda Integra “RS/LS/GS/SE/(GSI Australia)” (DC4/DB7)
• 1992–1996 JDM Honda Domani (MA5)
• 1993–1994 JDM Honda Integra (DB7)
• 1996–1999 JDM Honda Orthia (EL1)

B18B2

• 94-01 Integra RS/LS/SE/GS – DB7/DC4/DC3
• 1994–2001 Honda Integra “RS/LS/GS/SE/(GSI Australia)” (DC4/DB7)

B18B3

• 1992–1995 Honda Civic – Middle East & South Africa Ballade (SR4)

B18B4

• 1996–2000 Honda Civic – Middle East & South Africa Ballade (SO4)

JDM B18C Type R

• 95-00 Honda Integra JDM Type R (DC2 & DB8)

JDM B18C

• 95-98 Honda Integra JDM SiR/SiR II (DB8, DC2)
• 98-99 Honda Integra JDM SiR-G (DB8, DC2)
• 2000 Vemac RD180

B18C1

• 1994–2001 Acura Integra USDM GS-R (DC2 & DB8)

B18C2

• 1994-2001 Honda Integra AUDM/NZDM VTi-R

B18C3

• Honda Integra Asian market

B18C4

• 1996–2000 UK Civic VTi 5-door Hatch (MB6)
• 1996–2000 UK Civic 1.8i VTi-S (Limited Edition) 5-door Hatch (MB6)
• 1996–2001 UK Civic Aerodeck 1.8i VTi 5-door Wagon (MC2)
• 1998–1999 EU Civic Aerodeck 1.8i VTi 5-door Wagon (MC2)
• 1998–1999 EU Civic 1.8i VTi 5-door Hatch (MB6)

B18C5

• 1997-1998,1999 CDM, 2000-2001 Acura Integra USDM/CDM Type R

B18C6 (Type R)

• 1998–2001 Honda Integra UKDM/EUDM Type R

B18C7 (Type R)

• 1999-2001 Honda Integra AUDM/NZDM Type R

Honda B16 vs B18 Engines – Performance

As we have already established, the Honda B18 has an extra 0.2 liters of displacement over the B16. While that doesn’t seem like a very significant difference, the B-Series’ power-per-liter is very high, making the small displacement difference significant. Because of the B18’s different bottom end, and lack of VTEC (in most cases), it has different performance characteristics than the 1.6L B16 engine. Here is how the Honda B16 vs B18 engine stack up against one another in terms of factory performance.

Honda B16 Stock Performance

The B16’s over-square, or short stroke, engine geometry – meaning that its stroke is less than its bore – has its own benefits. In general, over-square engines tend to rev higher, deliver peak power higher in their range, and dissipate heat better than square or undersquare engines. The B16’s over-square design allows its redline to be higher than the B18. 

It also means that power and torque arrive near the top of the rev range, a perfect setup for performance driving. This is an aspect of the B16 that many Honda enthusiasts prefer. Since VTEC initiates at around 5,600-7,100 rpm on most B16 variants, most of the fun occurs at high RPMs. With that being said, one of the most common gripes with the Honda B16 engines is that it lacks any kind of low-end torque. Some prefer the B18 for that very reason.

Honda B18 Stock Performance

In contrast to the B16, the B18 has an undersquare engine design, meaning that its stroke length is longer than its cylinder bore. Undersquare engines tend to produce higher torque than square engines, especially at low-RPMs. That is certainly true of the B18 and a solid argument in favor of the 1.8L 4-cylinder for certain applications. However, the B18’s higher low-end torque comes at the expense of high-RPM power. In comparison to the B16, the B18 has a notably lower redline which puts some enthusiasts off. 

The unique characteristics of the B16 and B18 make each engine better for different applications. Due to the B16’s smaller displacement, higher compression, and top-end power delivery, the 1.6L 4-cylinder is a good option for those looking to build a naturally aspirated track car. As the Honda B18 engine family features lower compression than the B16, it is safer to run higher boost levels with the 1.8L B-Series variant. The B18’s low-end torque characteristic makes it the better choice for those looking for a high-horsepower street build. 

Honda B16 vs B18 Engines – Design Differences

In much the same way that a Honda K20 is similar to a Honda K24, the B16 and B18 engines are remarkably similar in terms of their overall construction. The same all-aluminum 4-cylinder arrangement remains unchanged between the two engines. In fact, the engines are so similar that B16 vs B18 cylinder heads are interchangeable. We’ll discuss that in greater detail in the following section. 

The most significant difference between the two engines, as we have already covered briefly, is displacement. The additional 0.2L found in the 1.8L B18 is due to the B18’s increased deck height and longer stroke as a result. In essence, the B18 can be thought of as a stroked B16 with a few additional differences. 

All of the main differences between the two engines arise from Honda’s attempts to optimize both engines based on the differences in engine characteristics. Let me explain. Going back to the fact that the B16 is an oversquare engine and the B18 is an undersquare engine, Honda optimized the internals of both engines to suit their strong points. For instance, B16 rods and pistons are lighter because they are designed to withstand high RPMs. In contrast, the B18 features thicker rods due to its lower engine speeds and longer stroke. 

Obviously, another extremely important difference between the two is the lack of VTEC from the majority of Honda B18 engine variants. While the Honda B18 was technically released following the B16, which all featured VTEC, Honda chose not to include it on most of the larger 1.8L engine family. Since the B18 produces more low-end power and torque, VTEC doesn’t necessarily play to the B18’s strengths. 

It is also said that some B16 cylinder heads flow better than the B18-variant heads that we received in the US. That makes it common to swap a B16 head on B18 lower ends.

Honda B16 vs B18 Engines – Modifications

Honda’s B-series is a fantastic platform for modifications. That includes both B16 and B18 variants. Both the B16 and B18 are known for their unparalleled build construction and ability to withstand huge amounts of horsepower with relative ease. While it is possible to dip into sizable horsepower numbers with any B-series engine, some are easier and more worthwhile to modify than others. 

In general, the performance B-series variants are more receptive to modification than the more economy-focused variants. The best B16 variants to modify include the B16A3, B16A2, and the second-generation B16A. The best B18 variants to modify include the B18B2, and B18C1.

Both the B16 and B18 are said to be able to handle 250-350 horsepower reliably with stock internals. While there are tons of examples of stock B-series pushing far more horsepower than that, 300 whp is about the highest safe figure. Both the B16 and B18 are highly receptive to simple bolt-on mods.

Some of the most common B-series mods include an intake manifold upgrade, cold air intake, 4-2-1 header, upgraded exhaust, FD2 throttle body, and upgraded ECU. A full-bolt-on setup like this will garner a horsepower figure close to 220-230 hp depending on the engine variant that you have. That’s a pretty impressive figure for not having to open the engine.

Obviously, even higher horsepower figures are possible with some internal upgrades. Modifications such as stronger valve springs and retainers, more aggressive cams, forged pistons, lightweight flywheel, and bigger injectors are all solid options for a naturally aspirated B16 or B18 build. 

Honda B16/B18 Hybrid Engine

Due to the fact that the majority of the Honda B18 engines we received in the US lacked VTEC, one of the most common modifications for those that have non-VTEC B18 variants is to swap a VTEC head onto their non-VTEC bottom end. This applies specifically to the B18A1, B18A2, B18B1, and B18B2 variants. The performance increase from doing this modification to a non-VTEC B18 is significant, with mild LSVTEC builds producing around 200 horsepower and more aggressive builds making close to 300whp. 

The DOHC VTEC head can be taken from a number of different Honda engines. The most common heads include B16, Type R, or GSR heads. At the end of the day, the head that you choose to use boils down to personal preference. Some people prefer the smaller combustion chamber of the P72 GSR head, while others like the B16 head as it allows for the higher-flowing ITR manifold to bolt on directly. Either way, any DOHC VTEC cylinder head will work. 

In addition to the non-VTEC B18 block and DOHC VTEC head, you’ll also need some other parts. One of the most important components is an LS VTEC oil supply kit, like the Golden Eagle B-Series VTEC Conversion Kit, which will allow the new DOHC VTEC head to be supplied with oil without the need for any independent machining. You’ll also need rod bolts, head studs, a new oil pump, GSR/ITR timing belt, and a modified ECU. 

In general, the LS VTEC is the most noteworthy and rewarding modification that you can do to a non-VTEC B18 engine. In fact, it is almost a necessity to make big naturally aspirated power from a B18 engine that is lacking VTEC.

Honda B16 vs B18 Engines – Forced Induction

Forced induction is undoubtedly one of the most common options for building a high-horsepower B16 or B18. Both engines are capable of running boost (at a moderate level) right out of the box. As we stated earlier, both the B16 and B18 can handle 300+whp with stock internals reliably. The same can be said when you mix forced induction into the equation. 

There are tons of off-the-shelf FI options available for both the B16 and B18. With that being said, the B18 is unquestionably the better engine to turbocharge or supercharge. Due to the Honda B18’s lower overall compression ratio, it can withstand a healthier amount of boost without risking the integrity of the engine’s internals. While it is still possible, and frequently done, turbocharging a Honda B16 will likely involve purchasing lower compression pistons and swapping to a lower compression head gasket.  

It is generally accepted in the Honda community that supercharging a K20 or K24 is less efficient. If you are shooting for extremely high horsepower numbers, a turbocharger and built internals are the way to go. A B16 head is generally stated to be better for forced induction as it has better flow figures than the B18. However, a B18 head can be ported and polished to achieve similar flow figures as one from a B16. 

Honda B16 vs B18 Engines – Price

One of the most important aspects of the B16 vs B18 engines debate, especially for those looking to engine swap, is price. Due to the fact that both the B16 and B18 were offered in so many variants and came in so many different cars, there are a ton of both engines out there. With that being said, there are fewer domestic Honda B16 engines available, as the B16A2 and B16A3 were the only variants to make it stateside. For that reason, the good B16 variants, like the B16B and B16A5 can be expensive to source, as they are all imports. If you are looking for a quality B16, you’ll also have to pay close attention to casting numbers as there are quite a few high-mileage imported B16s floating around which might be tired by this point.

In terms of sheer price, Honda B18 engines can be more or less expensive to source than B16s, depending on the variant. B18C1 and B18C5 variants are the most sought-after in the US due to the fact that they are factory equipped with DOHC VTEC. Due to the demand, they fetch a pretty penny. In comparison, B18B variants are still relatively inexpensive. Due to their lack of VTEC and widespread availability, they are both cheap and easy to find. If you are planning on an LSVTEC build, it is a good idea to start out with a B18B block as it will be the best value for money. 

Honda B16 vs B18 Engines Summary

The Honda B-series will go down in history as one of the best inline-4 layouts to ever be released. They are known for their bulletproof reliability, sturdy construction, VTEC inclusion (in the B16), and massive aftermarket support. 

In terms of overall construction, the B16 and B18 are similar in a lot of ways. The primary distinguisher between them is displacement. The B18’s extra 0.2 liters of displacement introduces different engine characteristics than the B16. With its under-square design, the B18 provides better low-end torque than the B16. However, the B16 provides better high-rpm performance than the B18. Most enthusiasts will make a decision on either of these motors for their particular application based on those characteristics.

Both the B16 and B18 are fantastic platforms for modifications and tuning. The B16 and B18 are perhaps two of the most supported engines in the world as far as aftermarket parts are concerned. Forced induction, either via supercharger or turbocharger, is one of the most common B-series modifications for big power. The B18 edges out the B16 as the best engine for boost due to its lower compression ratio and thicker rods.

If price is a serious consideration for you in deciding between the Honda B16 vs B18, the B18 – especially the B18B – is the more budget-friendly option. If you are sold on the idea of better low-end torque, a B16 VTEC head on a B18B block is a cheaper alternative to sourcing a B18C5.