An inexpensive solution for all you K20A, K20A2, K20A3, K20Z1, and K24A1 engine owners looking to simplify your cooling system! Weather you have added a radiator that does not have a radiator cap bung... or you are in need of a fill point higher than the rest of the system, we've got you covered.
The filler neck starts with a beautifully machined 6061-T6 flange that incorporates the largest port possible within the OEM gaskets footprint as well as a 1/2" NPT water bypass port and machined o-ring groove for the OEM gasket. You can chose from a list of options to make the product as unique as your project; including sensor ports for oem or aftermarket sensors, hose connection type and radiator cap bung type.
About the radiator cap bungs... the domestic style has a 1/8" NPT port and the import version has a 1/16" NPT for connection to an overflow. The domestic version uses any early model (mid 70's through late 80's Chevy) cap and the import version uses early model Honda (88'-91' Civic/ CRX and 90'-93' Integra) cap.
NOTE: Made to Order... usually a 2-3 day lead time - Contact for ETA - If you are interested in a specific design that varies from this, please email us at email@example.com. If using AN lines we also recommend designing the upper radiator hose so that there is droop/ give so the engines movement and does not push/ pull on the radiator and fatigue any parts. The tank is welded so that it sits level when bolted to an engine leaned back 15° (exhaust side) for the traditional option and leaned forward 8° (intake side) for the lean option.