Project G20 Race Car: Building a More Bulletproof SR20DE!


Martin Gonzales and Howard Watanabe lay out everything in the palatial MotoIQ Megashop in preparation for assembling the engine.

We sent out the engine to the machine shop to be bored out 1mm oversize. While the block was out getting machined, we took advantage of this time and sent the rotating assembly out to get balanced. The rods, pistons, crank, flywheel and pressure plate are all balanced. When using all OE parts it is not necessary to do this, but when building an engine using many after market components it is definitely a good idea. Balancing the rotating assembly will help our engine run smoother by reducing vibrations, which will in turn also help with long term reliability.


Our machine shop uses a deck plate as the SR20DE bores distort quite a bit when the head is bolted on.  The deck plate simulates the stress of the head being torqued on and is put in place while the block is being machined. This way the fresh bores will be round when the head is installed.

The machine shop also aligned bored the mains and decked the head surface. Our block is now true and square and probably better than when it left the Nissan factory.

 After machining, Martin thoroughly washes the block to remove all machining debris.
Martin uses Emory wet dry paper to break the edge at the top of the bores. Breaking the edges like this reduces the chances of damaging a ring during assembly.
Next, Martin sets the compression piston ring end gaps.  He starts by using a piston to push the rings down into the bore about an inch and to square the ring in the bore.

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