Coolant Crossover Pipes & Kits

Pockets of air or vapor can form inside the coolant passages of your engine block, and if they get stuck in there, they can prevent proper coolant circulation, creating “hot spots” that can throw off your tune, or even cause premature combustion. In engines where the thermostat sits at the highest point of the cooling system, these bubbles can easily escape. On other engines—most notably the LS—the thermostat is positioned lower, so the bubbles need another way out. The LS solves this issue with steam ports on the top of the block where these bubbles can escape, and coolant crossover lines (also called steam lines or pipes) carry them to the radiator overflow tank.

If you’re upgrading the intake manifold of your LS engine, you’ll need to remove the factory coolant crossover plumbing. While you’re at it, might as well upgrade the crossover as well! Aftermarket steam line kits are more versatile, provide better flow for improved cooling, are easier to service later, and look great, too.

Top Brands

An aftermarket coolant crossover helps your high performance engine run at peak efficiency and safety, so make sure you’re getting the genuine article at Summit Racing Equipment. Our selection only includes brands we’d use on our own project vehicles, like Trick Flow, Earl’s Performance, and Holley, plus kits from our own Summit Racing brand.