Ross Racing Pistons For roughly 4 decades now, Ross Racing Pistons has met the global racer demand, for the most advanced forged pistons in the racing industry. +1 (310) 536 0100 www.rosspistons.com Company Profile +1 (310) 536 0100 www.rosspistons.comCompany Profile Contact Us Facebook page Instagram Contact Us Facebook page Instagram How To Create Combustion Chamber Molds 27 September 2018 Clean both the chamber and head surface; chamber must be free of all dirt, oil and grease, and valves must be installed. Place cylinder head properly on the block using no head gaskets. Snug cylinder head bolts or studs with dowel pins installed. Turn block over until cylinder head is facing downward toward the floor. Cylinder head deck must be level before pouring mold. Insert plastic plug, or other stopper, into spark plug hole on the chamber side. Tap in if needed. Spray both the chamber and cylinder bore with WD40 or wipe down with a light coat of oil or silicone spray. Mix epoxy or Bondo as per manufacturer’s instructions. Pour mixture into combustion chamber from the bottom of block until epoxy covers at least .250” (6.5 mm) up of the cylinder bore from the head surface. Let epoxy or Bondo cure as per instructions that came with product. Once epoxy or Bondo has hardened, flip engine right side up and remove cylinder head. Before removing chamber mold from cylinder head, install dowel pins into cylinder head. Place a straight edge parallel with the dowel pins; using a razor blade, scribe a line on the back side of the mold. Scribe line must be on the chamber mold for us to scan. Scribe line is required to be parallel to the piston pin only. It is not required to be on the pin center line (see photograph). CARE MUST BE TAKEN TO ENSURE THAT THE SCRIBED LINE IS ABSOLUTELY PARALLEL WITH THE DOWEL PINS. Remove mold from chamber. If mold sticks, lightly tap with a plastic hammer or lightly pry with a screwdriver. Use alcohol to remove any WD40 or silicone spray left on chamber mold and cylinder head Related articles Ross Pistons Off-The-Shelf & Custom Motorcycle Racing Pistons Calculating Compression Height Ross Racing Pistons