Bought a 2013 G37 6MT about a month ago. I like it. I have a couple of questions about the engine.

First question:
I previously owned a 2003 Nissan Maxima. The G37's engine has a longer stroke length AND a higher redline RPM. How'd they manage to pull that off? If I visit the 6500-7500 RPM range with any frequency, is my engine going to age prematurely? This is particularly of interest now, since I just finished the 1200-mile break-in period yesterday.

Second question:
After cold-start, the engine seems to reach operating temperature a lot more rapidly than my Maxima. I know that some cars store heat by piping hot engine coolant through a thermos full of wax; then the next time the car starts, coolant picks up heat from the wax and warms up the engine more rapidly than it otherwise would. Presto: less cold-start wear, faster cabin heat, reduced cold-start emissions.

Does the G37 have something like that?

 

1st: bore and stroke are effectively irrelevant to engine red line. It's the sum total of engine design that determines engine operating RPM. No engine today will wear prematurely if operated within its designed limits.

2nd: are you using the temp gauge to determine when the engine reaches operating temp? I notice the G gauge rises very quickly so my hunch is it's in effect an "idiot gauge" - it's either on or off (i.e., not capable of showing an analog scale).

 

The more often you keep any engine near its redline, the greater the wear on all components. That's only common sense, it's going through more combustion cycles more rapidly at a higher temperature. However if its not being abused this engine will last a very long time.

The VQVHR engine is known to run warm, so yes it reaches operating temperature quickly. It revs high and has an 11:1 compression ratio. If its not running hot on the gauge (a little above half way), its normal.