Heat is the number one drivetrain killer, right? This includes your engine, and the same can be said for components, accessories, and electronics around the engine. So, short of freezing, you can probably never have your engine compartment too cool. Over the years we've seen different methods of getting heat out, from cutting holes or mounting fans in the hood to leaving the hood entirely off. But putting fans in the hood can give you maintenance issues, leaving the hood off makes everything in the engine compartment susceptible to debris or climate damage, and cutting holes in the hood can look sorta hack-unless you use louvers over them. Race Ace International has steel and aluminum hood louvers that will mount on almost any hood in polished, anodized, or powdercoated metal. They come with a nice easy kit, complete with the drill bit and rivets.
These were a natural choice and complemented our XJ hood nicely. XJs are known to run very hot under the hood, due to the large inline-six engine block and small engine compartment.
Temperature DifferencesWe used a temperature gun to check underhood temperatures before and after we installed the hood louvers, each time driving the same loop and starting with a cold engine. These are our results.
| Measured Area | Before Louvers (F) | After Louvers (F) |
| At the alternator | 179 | 149 |
| On the air filter | 123 | 108 |
| On the steel hood | 125 | 105 |
| On the hood brace | 150 | 132 |