Sunday, April 5, 2009




A version 2 model, applicable to exhaust side VTC.To meet modifications to inlet valve seat internal diameters and ports, two versions Spec-1, diameter 31 and Spec-2, diameter 32-was created.

Easy increase of compression ratio

Compared to a genuine VQ35 head, the combustion chambers of the genuine VQ30 are used as the base for casting a processing, providing the compact combustion chamber required by an NA engine. The volume has been greatly reduced. With the combustion chamber volume reduced from 56cc to 46cc, the compression ratio is increased without head milling (using a genuine piston, from 10.3 to 12.0). In addition, by changing the piston crown shape, a compression ratio of 13.5 is also possible.

Easy increase of intake port potential

While this head uses the dynamic valve system of the VQ30 engine, the intake port uses the high-potential port used in the VQ35. Spec-2 uses an intake valve seat diameter of 32 to modify the intake port inside R to realize performance that greatly exceeds that of a genuine VQ35 engine (please see the table at the VQ35 Intake Port performance comparison).
* The VQ35DE engine is a V6 engine using VTC. Do not use simple milling of the head to reduce combustion chamber volume.

Spec-1 secondary spec

Shape comparison, NISMO and genuine parts

Combustion chamber, Spec-1 secondary spec

Combustion chamber, genuine

Compared to genuine metal gaskets, the use of molybdenum coating helps withstand higher compression ratios and improves surface pressure around the bore.

The VQ35DE Metal Head Gaskets are 0.7mm thick and feature a 4-layer stopper-type structure. The stopper-type structure employs a stopper ring around each combustion chamber that is molded into the head gasket for a precise and strengthened seal. The factory head gasket is only made from 3 layers and has a bead-type structure. A bead-type head gasket only uses a raised bead to seal the combustion chamber.

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