B20A/B18A Engine Identification

Ok, there is A LOT, and I do mean A LOT of confusion around the B20A/B18A engines available for the Accord/Prelude

Most of the time the B20A will be confused with the B20A from the 88-91 Prelude and the B18A will confused with the 90-93 Integra B18A1. Let me tell you that these engines aren't the same despite their same numbers.

The advised eye can tell the difference between the engines but when shopping for those, it comes in handy to have another way to tell them apart other than some slight visual differences (especially over the phone or the internet)

The chart below shows you the engine code, the serial number and the car it came from.

Here is what the numbers could look like on an Accord B20A. That number is located just under the timing adjustment plug, on the left side of the exhaust manifold.

B20A DOHC PGM-FI

• B20A-1000001~ (Prelude BA1-1000001~)
• B20A-1000001~ (Vigor CA3-1000001~)
• B20A-1050001~ (Prelude BA1-1040001~)
• B20A-1500001~ (Accord CA3-1000001~)
• B20A-1550001~ (Accord CA3-1060001~)
• B20A-1550001~ (Vigor CA3-1060001~)

• B20A-1600001~ (Accord CA3-1200001~)
• B20A-1600001~ (Vigor CA3-1200001~)
• B20A-1640001~ (Accord CA3-1300001~)
• B20A-1640001~ (Vigor CA3-1300001~)

B18A DOHC Dual Carb

• B18A-1000001~ (Accord CA2-1000001~)
• B18A-1000001~ (Vigor CA2-1000001~)
• B18A-1040001~ (Accord CA2-1060001~)
• B18A-1050001~ (Vigor CA2-1060001~)
• B18A-1050001~ (Vigor CA2-1300001~)
• B18A-1080001~ (Accord CA2-1200001~)
• B18A-1080001~ (Vigor CA2-1200001~)
• B18A-1110001~ (Accord CA2-1300001~)

The 88-91 Prelude (Prelude BA5 and BA4) will have their engine numbers beggining like this:

• B20A-5500001~
• B20A-5550001~
• B20A-5600001~
• B20A-5650001~

• B20A-5000001~
• B20A-5050001~
• B20A-5100001~
• B20A-5150001~

As you can see, they do not match the B20A serial numbers I posted above for the Accord/Vigor/BA1 Prelude

The B18A1 engine was not available in the Japanese market. The 2 engines that were available in the integra at this time were the ZC (sohc, PGM-FI 1.6 liter) and the mighty B16A.

The only way to find the B18A1 is through a USDM Integra, thich can't be confused with the B18A from the Accord since the B18A is dual Carb

Here's a picute of the Accord B18A

If you want to see the picture of a B20A just click on the "My Car" section on the menu to the left

Conclusion

All you need is to make sure is that the engine serial number matches those for the Accord/Vigor CA-3 or Prelude BA-1.

You can now tell the engine importer to check the number on the block without any worries of getting the wrong engine.