Abstract: An apparatus for fluid pressure testing of engine cylinder heads and similar parts by sealing the fluid circulating jacket ports and subjecting the head to a fluid pressure comprising, a lockable pivoting frame structure on which the head is positioned and secured by clamp bars, individual port closure members secured to the cylinder head by clamps and bolts so as to seal the cylinder head ports and a modified port closure member when connected to a pressurized fluid supply conduit allows a pressurized fluid to be introduced into the fluid circulating jacket.