Honda B20 Engine Guide

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The Honda B20 made its debut in 1985 in the form of the B20A engine. B-series engines were based on the B20A, but the B20A isn’t considered part of the B-series engine family. That engine family consists of the B16, B17, B18, and B20B with the latter the primary focus in this article. The B20B 2.0L inline-4 came out in 1996 and was predominantly used in the Honda CR-V from 1996-2001. Despite its limited use, the B20 is a great engine that can make for a great swap. In this guide, we discuss Honda B20 engine specs, problems, reliability, mods, and more.

Honda B20 Engine - B20 2.0L Specs, Problems, Reliability

Again, the B20B is not to be confused with the older B20A3 and B20A5 engines. It’s a bit confusing since the previous engine shares the same B20 engine code, and the B-series was built on that design. However, most parts on the older B20A are not compatible with the B-series engines. The B20A was primarily used in the Honda Prelude from 1985 to 1991 as well as some Accord’s.

Engine Specs

EngineB20B-B20B4B20Z2B20B JDM*
Displacement1973cc (2.0L)1973cc (2.0L)1973cc (2.0L)
Compression8.8:1 or 9.2:19.4:1 or 9.6:19.2:1
Bore x Stroke84mm x 89mm84mm x 89mm84mm x 89mm
Horsepower126-142 HP148-150hp126-148 HP
Torque133 lb-ft140 lb-ft131 lb-ft

*The B20B JDM engine was produced from 1995-2002, but there were a few changes after 1997. Some of those changes include compression bumping up to 9.6:1 and a lower 6,500rpm redline. Specs above are shown for the 1995-1997 JDM engine.

All these engines are a part of the same B-series engine family and all share the same 2.0L displacement. As such, Honda B20 engine specs are pretty similar between the engines. They are all non-VTEC, share the same block, and have the same 84x89mm bore and stroke.

Notable changes across B20 variants are the compression ratio and power output. The 2.0L B-series engines make anywhere from 126-150 horsepower and 131-140 lb-ft of torque. It may sound underwhelming, but this was respectable power from a 1990’s 2.0L engine. That’s especially true in light-weight Honda’s.

B20B 2.0L VTEC Engines

None of the B20B engines feature VTEC from the factory. However, a popular mod is swapping a Honda VTEC cylinder head onto the B20B engine. The Honda B20 makes good low-end torque thanks to its larger 2.0L displacement (relative to the smaller B-series engines). Adding VTEC to the B20 adds plenty of top-end power for an awesome engine build.

Ultimately, swapping a VTEC head onto the B20B requires a lot of research and time. It’s too much to cover in this article alone, but we wanted to highlight that it’s very possible. It also leads into the next section where we discuss Honda B20 engine upgrades and mods.

Performance & Mods

The B20B engine is a popular swap for 1980s and 1990s Honda Civic and CRX models. They’re extremely light-weight which means you can build a very quick Honda even with just 200-250 horsepower. B20 engines are very capable of those numbers even without forced induction. Some of the best B20 2.0L inline-4 engine mods include:

  • VTEC cylinder head
  • Headers
  • Intake
  • Cams
  • Tuning

With the above upgrades, the B20 can produce some great power and torque. If you really want to push the limits and make 200+ horsepower then it does require some work. You’ll likely want to consider upgrades within the cylinder head along with ARP rod bolts, head studs, and more.

This is another topic that’s simply too much to cover in a general Honda B20 engine guide. We’ll likely have a mod-specific B20B guide in the future to dive further into this info. For now, the important note is that the 2.0L inline-4 engine is plenty capable – especially in smaller, light Honda cars. In the meantime, check out this awesome B20 Civic build on Motortrend.

Most Common Engine Problems

  • Cam seals
  • Head gasket
  • Water pump
  • Timing belt

In the next few sections, we will examine each of the above Honda B20 engine problems. It’s important to add a few quick notes before diving in, though. These are some of the most common Honda 2.0L inline-4 engine issues. That doesn’t mean they’re common in the true sense of the definition. Instead, when problems do arise these are a few of the most popular areas.

That said, the B20B offers good overall reliability. The lack of VTEC also makes maintenance and repairs easier should any cylinder head issues arise. Anyway, we will circle back to B20 reliability after working through the common engine issues.

1) Cam Seal Issues

Cam seal problems on the B-series engines primarily affect VTEC motors. As such, this isn’t as common of an issue on the non-VTEC Honda B20 engines. It’s still worth the mention since it’s so common on the B-series and can still affect the B20. It’s also something to keep in mind if you plan on swapping a VTEC head on the B20B.

Fortunately, cam seals are a very simple problem and there are proven long-term solutions. The cam seals simply harden and crack with age and begin leaking oil. The front cam seal on the B-series engines is the main culprit.

A simple solution is replacing the OEM cam seal with an aftermarket aluminum option. These aluminum cam seals use rubber O-rings to create a seal, and those O-rings could still degrade and leak over time. The point is – it’s not a totally bulletproof solution but they have proven to improve reliability over the OEM seals.

Ultimately, this is a very minor issue in the grand scheme and less common on the B20 compared to the VTEC B16 or B18. If you’re swapping a VTEC head or working in the general area then it won’t hurt to opt for an aftermarket seal. Check out options like this Add W1 cam seal for just $10. It’s a cheap and simple fix that should outlast the OEM replacement options.

Cam Seal Leak Symptoms

  • Visible oil leak
  • Smoke from engine bay
  • Burning oil smells

A visible oil leak is the most common symptom of front cam seal oil leaks. If the leak is bad enough you might also notice smoke from the engine bay or burning oil smells. However, you’ll likely notice a visible oil leak before it gets too bad.

2) Head Gasket Failure

Another common issue on the B-series and B20 is head gasket failure. Part of this can be chalked up to age and mileage on most B-series engines now. The head gasket usually lasts 120,000+ miles, but most B20 engines are likely past that mileage by now. Age and mods can also take a toll on head gasket longevity.

Anyway, blown head gaskets and leaks can be time-consuming and costly issues so it’s important to be aware of them. If you’re swapping a VTEC head then you should opt for a new head gasket. However, it’s a toss-up as to whether to use an OEM B20 non-VTEC gasket or an aftermarket VTEC gasket. People have seen success and failure with both routes, so there isn’t a perfect solution.

Head gaskets require removing the entire cylinder head so it’s a labor-intensive problem. If you end up at a repair shop for Honda B20 head gasket repairs you could end up with a $600-800+ bill. Fortunately, it’s cheaper than replacing head gaskets on many other engines but it’s still not cheap.

*If you’re ever replacing the head gasket it’s a good idea to also replace the water pump and timing belt. There’s a lot of overlap in labor so you can save time or money by knocking this out at the same time.

Head Gasket Failure Symptoms

  • Oil/Coolant mixing
  • Rough idle
  • Low coolant
  • White smoke from exhaust
  • Overheating

Head gasket failures are serious issues that warrant immediate replacement. Oil and coolant can mix together which can be dangerous for the engine due to poor lubrication. You may notice drivability issues like a rough idle. Also lookout for low B20 coolant levels, white smoke from the exhaust, and overheating.

3) Water Pump Problems

Next up are water pump failures on the Honda B20B 2.0L inline-4 engine. Again, this might not be fair to call a common issue and is more so just standard maintenance and age-related. Nonetheless, over time the water pump takes a lot of abuse and can develop leaks or shaft problems. The weep hole is the most common point of failure and that’s usually where you will notice coolant leaks.

Thermostats are another common issue within the cooling system, so that could also be a cause of the problems. Anyway, the water pump usually develops a leak instead of a complete shaft failure. However, if the B20 water pump shaft does fail that can lead to overheating. If not fixed in a timely manner that may lead to more severe issues like head gasket failure.

The Honda B20 water pump is driven by the timing belt, which is an issue we’ll be discussing next. Both items are also easy to replace if you’re ever doing the head gasket. Ultimately, you can save some time and money by taking advantage of overlapping labor.

2.0L Inline-4 Water Pump Symptoms

A few symptoms of water pump issues on the Honda B20B 2.0 inline-4 include:

  • Coolant leak
  • Coolant loss
  • Overheating
  • Bubbling coolant

Again, the primary failure of B20 water pumps is a simple leak from the weep hole. This leak generally isn’t a cause for major concern as long as the leak is small and you’re coolant is topped off. Otherwise, complete water pump failure can lead to engine overheating, bubbling coolant, and similar problems. This is a bigger concern and should be replaced as soon as possible. Continual or serious overheating can lead to more serious issues in the longer-term.

A water pump failure may also trigger a check engine light and fault code. Using an OBD2 scanner to read the codes can help narrow down the issue and potentially point you in the direction of the water pump.

4) Honda B20B Timing Belt

Honda B20 timing belt is yet another problem that mostly boils down to standard maintenance. The timing belt should be replaced roughly every 6-8 years or 90,000 to 105,000 miles. Age can be just as tough on timing belts so don’t skip over B20 belt replacement even if you’ve only driven 30,000 miles in 8 years.

The B20B is an interference engine which means there is some overlap in the area the pistons and valves travel. If the timing belt fails then timing can skip. In this case, it’s possible for valves and pistons to collide. Valves then end up bent and piston damage can possible happen too. Not good.

Ultimately, don’t overlook the Honda B20 timing belt. Premature failures can and do happen but it isn’t terribly common. As long as you maintain the timing belt you likely won’t run into these problems. It’s just important to keep in mind due to the interference design of the B20 2.0L inline-4 engine.

B20B Engine Reliability

Is the Honda B20 engine reliable? Yes, we believe the B20B 2.0L engine earns above average remarks for reliability. Many of the common problems on the B20 are simply due to the age and mileage of these engines. Outside of head gasket failures most of the issues are also cheap and easy to fix.

Of course, the B20 is a 20+ year old engine as of now. Older engines naturally require some extra TLC – even low mileage examples. Age can take just as much of a toll on parts like gaskets, seals, belts, and more. Keep that in mind if you’re looking for an older engine like the Honda B20B.

That said, keep up with standard maintenance, use quality oils, change fluids on time, and fix problems in a timely manner. Do all this an the B20 can deliver excellent reliability and longevity. It’s not uncommon for the B-series engine to surpass 250,000 miles with few issues along the road.

Like B Series, we have also curated Honda D16 guide and Honda K20Z3 engine guide. If you are interested, please click here for more details.

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