OEM 2007 Jeep Wrangler Exhaust Valve

2007 Jeep Wrangler Exhaust Valve Parts and Q&A

• Q: How Do Exhaust Valves and Intake Valves Impact the Refacing Process and Key Considerations on 2007 Jeep Wrangler?

  A: Each valve seat is machined to the necessary angle; after refacing the valves, check the remaining margins. When refacing a valve seat, don't take any metal off of the cylinder head, only from the seat. Match the proper size valve guide pilot when placing the stone to secure a correct and full surface. Check that the valve seat is concentric with a dial indicator; avoid having a total runout bigger than 0.051 mm (0.002 in.) total indicator reading. Run a thin layer of Prussian blue onto the valve seat, fit the valve in and rotate it with only slight pressure; ensure that Prussian blue is seen in the very center of the valve face for proper contact. If the blue is at the top of the punch, lower the valve seat with a 15-degree stone, but if it's on the bottom edge, raise the valve seat with a 65-degree stone. As long as the proper angle and size of the valve seat are kept, the valve seats can be fixed; if they aren't, changing the cylinder head is required. Intake and exhaust seats on the manifold should range from 1.50 to 2.00 mm (0.059 to 0.078 in.). After grinding the valve seats or faces, set the valve in the cylinder head and find the valve installed height from the valve tip to the spring seat. Should the valve need trimming, grind it down to meet the specs and look for any signs of scoring; if you find any, you should regrind the tip chamfer to ensure the seal isn't harmed. Be sure to check the valve spring installed height after refacing; if it seems too high, add a 0.794 mm (0.0312 in.) spacer to the head counterbore to make the spring meet the requirements.