Reference Manual

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Chapter 1: Engines: Buick V6: Modifying

All Buick V6 engines came from the factory, in Olds A/G-bodies, with 2-bbl Rochester Dual-jet carburetors. They had two throttle bores and a hot-air style choke. Rated power was 110 hp @ 3000 rpm and torque was 200 lb*ft @ 1600 rpm. As with everything from the factory, there is a compromise between many factors such as driveability, emissions, performance, and mileage. The 3.8L V6 is an efficient engine and should produce years of trouble-free duty.

However, there are a few things which can be done to these engines to make them a little more peppy than what GM had in mind. One of the most popular upgrades is changing the induction to a 4-bbl carburetor and intake manifold to match. If you are intent on keeping the computer on the vehicle, there is a fairly easy solution: install a Rochester Quadra-jet carburetor and 4-bbl intake manifold from any early '80s Riviera or Toronado with a 4.1L V6. These engines shared the same basic block as the 3.8s, but had a slightly larger bore to achieve the 4.1L displacement; they also had a Q-jet carb and 4-bbl intake, which, in combination, is a direct bolt-on to any 3.8L engine.

Other options are looking to third-party manufacturers for performance products. Both Edelbrock and Holley manufacture intake manifolds for these engines. They both provide provisions for either a spread-bore carb (like the Rochester Q-jet) or a square-bore carb (like most Holleys). The recommended CFM (Cubic Feet per Minute) rating for a 4-bbl carb for these engines is between 390-cfm and 600-cfm.

• Edelbrock RPM P/N: 5486
• Holley (Weiand) P/N: 7541