What is the differance between a 3800 v6 and a 3800 v6 series 2?

GM’s 3800 V6 has four stages of evolution: pre-series 1, series 1, series 2 and series 3. Pre-series 1 & series 1 are similar while series 2 & series 3 are similar.

Some of the major changes that occurred from series 1 to series 2 include redesigned main bearing caps, redesigned cylinder heads and shorter deck height. These changes resulted in an increase from 170hp and 220 lb-ft of torque to 205hp and 230 lb-ft. Compression also increased from 8.5:1 to 9.4:1. Another advancement for series 2 was sequential fuel injection (SFI) instead of the previous tune port injection (TPI).

Introduced in 1988, the first 3800 is known as the pre-series 1, officially this is the LN3 engine. In 1991 the series 1 was released. One major change was the addition of a PCV (Positive Crankcase Ventilation) valve. Series 1 was available both naturally aspirated and supercharged. These were officially known as L27 and L67 engines.

Series 2 became series 3 in 2004. Changes included an aluminum intake manifold and fly-by-wire throttle control. These were the naturally aspirated L26 and supercharged L32.

The 3800 V6 has appeared in GM brands across the board, including Pontiac, Buick, Oldsmobile and Chevrolet. The 3800 is an evolution of a design that originated at Buick.