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The Oldsmobile V8 can be modified for excellent street or track performance with careful planning and attention to the overall combination. The large and small block engine variations use many similar components, including a common cylinder head layout. The small block engine is not often found in today's performance applications, although the factory offered a high powered W-31 version. The larger displacement engines are fairly common, having been used in many large luxury cars, and form the basis for most high output Oldsmobiles. The 455 can generate considerable torque, and is at it's best when optimized for low and midrange power. The W-30 package was among the strongest engines available during the muscle car era, and when altered to work with currently available fuels, is a good baseline for streetable performance. The CS176R cam has the original profile for the W-30 package. and is the largest

cam practical for a street driven vehicle. This cam is marginal with power accessories.


Oldsmobile cylinder heads are commonly identified by a letter cast into the exhaust side of the head. The most desirable heads include those with the letters C, D, F or H. While most of these heads will physically bolt on to any Oldsmobile block, pay close attention to valve size and chamber volume when selecting the ones to use with your combination. A cylinder head with large valves may lessen street driving performance in smaller engines. As produced, Olds cylinder heads use a non-adjustable valvetrain where rockers are paired with a common pivot "bridge". The O.E. aluminum bridge has been known to break in service, we offer both the original style and a three piece unit with separate fulcrums and a steel connector


As in any performance engine rebuild, you should pay close attention to clearances. The minimum piston to valve clearance is .100". Piston to cylinder head clearance minimum is approximately .040". The valve springs must have an additional .060" of available travel at maximum valve lift to prevent coil bind. Piston to valve clearance must be reinspected whenever you mill the block or heads, change cams, or alter cam timing.


 Identification of Oldsmobile engines can be a challenge. as many of them were marked at the factory with only a paper tag on the oil filler tube. These tags are often missing by the time the engine falls into the hands of an enthusiast who wants to rebuild the engine. Do a little research to be sure of the engine you are working on prior to ordering parts. It is not unusual to find 455 Oldsmobile engine blocks with cracks around the left motor mount area, and along the water jackets on the deck surface. These areas should be carefully inspected prior to machine work. Cracks in these areas are difficult, if not impossible to property repair. The use of a torque reaction limiting strap or cable should be considered in high powered applications, in an effort to reduce stress on the motor mount portion of the block casting.


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