In our last story, we gave you a sneak peek and a technical overview of the parts we were going to use on our naturally aspirated VQ37VHR engine with some special help from Jim Wolf Technology and Z1 Motorsports. Now its time to assemble our engine and get it ready for installation in this 370Z. First lets go to Jim Wolf Technology to see how our heads were prepared.
The VQ37VHR cylinder head is a complicated part. The VVEL or continuously variable intake valve lift and timing system adds a lot of complexity to the engine build. We first did our valve job with a CNC Newan valve seat cutting machine that opened up the valve seats for a larger Titan truck exhaust valve. The Titan valve is sodium filled for better cooling and is 1 mm larger for better flow. The Newan machine cuts the seat and blends it into the intake port and combustion chamber in a smooth radius which really improves the flow.
To finish the complex VHR head we went to Jim Wolf Technology as they are experts in all things VQ. To get a perfect valve seal, JWT lapped our valves with a torque plate bolted to the head. The torque plate simulates the distortion of the head being bolted to the block
The torque plate was installed on the heads with some used OEM gaskets and OEM torque to yield bolts.
Here JWT’s Clark Steppler installs the toque plate on our heads. Afterwards our valves were lightly hand lapped to the seats to make a perfect seal.
Now Clark bolts the head to JWT’s flow bench to see if our heads flow like some of the ones they have done for some of there race program VQ builds.