Hollow Stem Valves

SSDiv6 · 02-07-2019, 11:35 PM

Section 11A, page 3, Stock Cars, Cylinder Heads:

"Any aftermarket steel valve permitted, must retain stock head and stem diameters. Only engines OEM-equipped with sodium-filled valves may use sodium-filled replacement valves. Titanium prohibited."

Super Stock Section 12A, page 2

"Any aftermarket steel valve permitted; must maintain stock head and stem size; titanium valves prohibited. (OEM sodium-filled valve may be replaced with titanium, provided weight is equal to or greater than original.)

The current rule as written for Stock, can be interpreted that as long as they are Steel and not Sodium Filled or Titanium, they are acceptable.
For Super Stock, Sodium filled can be replaced with Titanium.

02-07-2019, 11:35 PM	#4
SSDiv6 VIP Member Join Date: Feb 2003 Location: Glendale, Arizona Posts: 3,044 Likes: 712 Liked 1,580 Times in 582 Posts	Re: Hollow Stem Valves Section 11A, page 3, Stock Cars, Cylinder Heads: "Any aftermarket steel valve permitted, must retain stock head and stem diameters. Only engines OEM-equipped with sodium-filled valves may use sodium-filled replacement valves. Titanium prohibited." Super Stock Section 12A, page 2 "Any aftermarket steel valve permitted; must maintain stock head and stem size; titanium valves prohibited. (OEM sodium-filled valve may be replaced with titanium, provided weight is equal to or greater than original.) The current rule as written for Stock, can be interpreted that as long as they are Steel and not Sodium Filled or Titanium, they are acceptable. For Super Stock, Sodium filled can be replaced with Titanium. Last edited by SSDiv6; 02-07-2019 at 11:40 PM.