How Does the Engine Cool After EPOXY54?

How Does the Engine Cool After EPOXY54?

One of the most common questions we hear is: “If you’re filling the block with epoxy, how does the engine cool afterwards?” 

Closed Deck vs. Open Deck Cooling

  • Many modern race-inspired engines come factory with a closed deck design.

  • A closed deck supports the cylinder walls for strength, while still allowing coolant to flow around the cylinders.

  • Older open-deck engines typically leave these areas unsupported (mainly for cost-saving reasons).

Our epoxy filler replicates an OEM closed deck solution: it strengthens the block while maintaining coolant flow.

How Coolant Flow is Preserved

After the epoxy has cured, we carefully re-establish coolant passages:

  1. The block is first taped, filled with sugar, and poured with epoxy to the correct height, leaving clearance for coolant channels.

  2. Once cured, the head gasket is used as a template to mark coolant holes.

  3. A 3/32 drill bit is used to reopen these passages, ensuring coolant can still flow just as it would in a factory closed-deck engine.

The Result

  • Cylinder strength of a closed deck → less risk of cracking or distortion under high boost.

  • Full coolant flow preserved → the block still cools like OEM.

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