How do I identify my Volvo Penta gas engine and what does the model name tell me about the engine?

A metal tag is riveted to all Volvo Penta engines. Some of our products also have the information on a decal on the top of the product. Locate any of these on your engine and you will know the model. In the case above the name is 5.7Gi-B.

What does the model name tell me about my engine?

Several methods have been used to provide the engines with unique names. Some were based on horsepower ratings. More recent names are based on the displacement of the engine in liters.

Each time the name was changed, it was due to some change in the parts content of the engine. Sometimes the changes were minor, sometimes they were major. The changes may or may not affect the parts that you need for example a repair.

There are three distinct periods of gas engine production, each with a different naming method.

Red Engines, early

Very early engines, built until the late 1980.s, were named based on the displacement (early) or horsepower (later) of the engines. The name started with AQ (sterndrive engine), BB (inboard) or MB (inboard). Next came the number for the displacement or horsepower. Most of these also included a one letter suffix, for version control. An AQ271A is older (and different) than a AQ271B.
Examples: AQ260A, AQ171C, AQ200F, BB260A

These engine names then changed to a system based on displacement. The names were a three digit number, followed by a letter. The first two digits of the number represented the displacement. The 43 in 434A meant the engine was a 4.3L. The third digit was used for version control. A 430 and a 431 are both 4.3L.s, however the last digit indicates there is difference between the engines. The numbers at the third digit were not always sequential. 430.s were built before 431.s, however 432.s and 434.s were built at the same time.

The letter at the end was also used for version control and was sequential. A 500A was built before a 500B. These engines went out of production in 1993.
Examples: 432A, 500B, 251A, 740B

Nothing in the names in either of these systems relates in any way to years of production. Some of these engines were in production for less than a year, others for many years.

Charcoal engines

These engines were built during the joint venture with OMC and were painted a dark charcoal color. They were usually named by long character strings that contain two numbers followed by a series of letters.
 

• The two numbers are the displacement.
• Next is the letter that indicates who made the base engine. ( G=GM, F=Ford)
• After that, one or two letters that note the fuel system and/or output. L=Limited, S=Superior, X=Exceptional, i or I=Fuel injected (no I means carburated).
• Then one letter for the steering system. P=Power steering, M=Manual steering, X=Exact steering, I=Inboard
• The next two letters are the most important for finding parts. These are random letter pairs that indicate the years of production for the engine. All parts information for these engines is based on these letter codes, including the charts that follow later in the book.