Cowl Hood Flapper: Making It Work With An LS Engine
Arguably one of the most iconic muscle cars ever, the 1970-1972 Chevelle set the bar. One of the coolest features these cars could be ordered with was the double cowl induction hood. This hood had a flapper door that stood up when at full throttle to let more air come in to the air cleaner assembly. Even if they didn’t do all that much, they sure looked great.
When running a Big-Block under the hood in a somewhat factory configuration, it’s easy to get this hood flapper to work. All you have to do is call our helpful Techs who will get you all the parts needed to bolt it all in. What if you’re running a modern LS engine like so many of us are? Is it still easy? YES! Watch this video from Grosse Performance who will show you how it’s done.
As you can see, in order to get the factory cowl induction flapper door to work, you pretty much need all the factory parts and then a vacuum feed from your LS engine. There’s check valves, vacuum pods and linkages to make everything work as it should. When the door doesn’t see vacuum, it’s open. When the door does see vacuum, it closes.
We offer everything you need to get your factory flapper door working with your LS engine. In fact, we even offer a complete kit with the hood too! Check it out here, which also has a list of parts in it. If you want to print out instructions on how everything fits together and links for all the parts, click here for that. If you have any other questions, feel free to give our techs a call at (866) 358-2277