What would make a Chevy small block sound like popcorn when you start it?

There are a few reasons why a Chevy small block engine might make a popcorn popping sound when you start it.

* Loose valve lash. This is the most common cause of popcorn popping sounds in Chevy small blocks. When the valve lash is too loose, the valves don't close all the way, and the air/fuel mixture leaks past them. This creates a popping sound as the mixture burns in the combustion chamber.

* Lifter noise. Lifters are small cylindrical components that help to open and close the valves. If the lifters are worn or damaged, they can make a popping sound when the engine is running.

* Timing chain. If the timing chain is stretched or damaged, it can cause the engine's timing to be off. This can lead to a popping sound when the engine starts, as the air/fuel mixture is ignited at the wrong time.

* Spark plugs. If the spark plugs are worn or fouled, they can cause the engine to misfire. This can also lead to a popcorn popping sound, as the air/fuel mixture is not being burned properly.

If you hear a popcorn popping sound when you start your Chevy small block, it's important to take it to a mechanic to diagnose the problem and get it fixed.