How to Troubleshoot a Small Block on a Chevy

The Chevrolet 434 cubic inch small block engine is a popular engine used in drag racing. These engines are smaller than the 565 cubic inch big block engines. Because of their smaller size, the small block often uses a high compression ratio for more low-end torque. This, however, also means that there are more reliability problems with the small block. If you're having trouble with your Chevy small block, you'll want to troubleshoot some of the more common problems before fixing anything.

Difficulty:

Moderately Easy

Instructions

1. Start the engine. Listen for a constant ticking sound. It will be rhythmic as the engine runs. This ticking sound is caused by a misaligned rocker arm. You must have a professional mechanic adjust the rocker arm.

2. Listen for pinging while the engine is running. The pinging of the small block will be noticeably different from any other sound you hear coming from the engine. A metallic pinging means that the octane of the fuel you are using is too low and the engine is detonating too early. This is a very common problem with small block engines, because owners don't understand or don't know that a high-octane fuel above 91 or 94 is often required. To stop the pinging, you will need to switch to a higher octane fuel.

3. Check for oil leaks. Oil leaks are easy to detect in the small block and are a result of the compression ratio in some of the blocks that have been ported. Oil leaks by the piston seal rings into the combustion chamber. The oil burns and is sent out the tailpipe. If there is enough oil being burned, the smoke coming out of the exhaust will turn blue. At this point, you must replace the piston rings.

4. Check for a leaking head gasket. A leaking head gasket will present itself as either white "smoke," which is actually steam, coming out of the tailpipe, or you will notice the fluid levels in the radiator reservoir constantly being depleted as a result of normal driving. You must replace the head gasket at this point to prevent damage to the engine.

References

• "Chevrolet Small-Block V-8 ID Guide: All Chevy Small-Block Engines Since 1955;" Pierre Lafontaine; 1996