Reinforced exhaust valves Nissan 350Z Murano Pathfinder VQ35

Nissan engines covered

The VQ35 is Nissan's 3.5 litre V6 with twin camshafts per bank and 24 valves. It powers the 350Z from 2003 to 2008, the Murano II, the Pathfinder II and IV and the Teana III.

Its two cylinder heads carry 12 exhaust valves. Nissan lists them as 13202-8J100 or 13202-8J110 on the VQ35DE and 13202-JK21A on the VQ35HR, held by 13210-53Y00 collets; FERREA reproduces them with a 31.35 mm head, a 5.96 mm stem and a 94.4 mm overall length. On a V6 that happily revs high, these valves take long periods at high temperature.

SUPERTECH and FERREA reinforced exhaust valves

The exhaust valve opens into the flow of burnt gases: its head reaches 760 to 870 °C on a naturally aspirated engine and goes beyond 1,000 °C with forced induction, measured in the metal. About 75 % of this heat leaves through the seat and 20 % through the guide. As Nissan does not publish its valve grade, an EV8 family steel is the benchmark: 550 MPa at 600 °C, 300 MPa at 800 °C. Beyond that, the head fatigues, warps and loses its seal.

FERREA offers its 6000 series (F6017, F6018) and its Competition Plus range, in Special Alloy (F1564P) and Super Alloy (F1565P, listed for turbo applications); FERREA rates the Competition Plus at +20 % hot strength and +25 % seat life. SUPERTECH adds an Inconel valve (NEVI-1028F), a nickel-based superalloy that keeps 860 MPa at 732 °C and 554 MPa at 816 °C, around 85 % more than the original steel near 800 °C, the one to favour for forced induction.

The +1 mm versions take the head to 32.35 mm: the burnt gases leave faster and scavenging improves, FERREA quoting 10 to 12 cfm of flow per millimetre of head. The 12 exhaust seats are then machined to that diameter.

Exhaust valve technical specifications

FERREA note: F6017 and F1564P "Stock size", F6018 and F1565P "+ 1 mm oversize", radius groove ("Radius Groove"). SUPERTECH note: the NEVI-1028F is listed as "32.35 (+1)".

Valve fitting

FERREA lists a radius groove ("Radius Groove"): check that it matches the 13210-53Y00 collets you reuse before refitting the springs.

At 31.35 mm the seats keep their diameter; with a +1 mm version, the 12 exhaust seats are cut to 32.35 mm.

For valve stem seals, Nissan fits 13207-84A00 or 13207-D4201; the original exhaust valve guide is 13213-31U60.

Technical guide

Our brands

	SUPERTECH Performance has been making competition valves in California for more than thirty years. For the VQ35 it offers a +1 mm Inconel exhaust valve.
	FERREA, founded in 1978, produces its valves in Florida and Argentina. For the VQ35 it offers its 6000 series and its Competition Plus range, in standard size and +1 mm.

How to choose

As the radius groove is common to the FERREA valves, the choice comes down to size, range and use:

When reinforced valves become necessary

• More aggressive camshafts or uprated springs
• Engine often run at high rpm
• Turbo or supercharger (Inconel version recommended)
• Track days
• Cylinder head rebuild with marked exhaust valves

Vehicle compatibility

OEM part number (exhaust valve): 13202-8J100 / 13202-8J110 (VQ35DE), 13202-JK21A (VQ35HR)

Don't forget the inlet valves

When the cylinder heads of a VQ35 are off, replace the inlet valves and the valve stem seals as well.