Recently built this for a budget endurance racer and thought I'd share. The goal was to stay as cheap as possible, be relatively reliable (not expecting to get 100K out of this motor, but would like it to make it through a few endurance racing weekends), and make decent power for what it is. Here's the stuff:

-Messed-up Z6 motor, ate the main bearings, was running (barely), but lots of smoke coming out of it and using a lot of oil and coolant, got it for $50
-eBay Nippon Racing stock bore P29 piston set -w- main and rod bearings and rings for $111 shipped, these were pressed onto the stock rods
-Block was not bored, but we put a new crosshatch in it with a drill-mounted hone to cut the glaze so the rings would seal
-found a used Zex/Comp 59300 cam on CL for cheap
-DIY head porting with a die grinder
-DIY block windage clearancing with a die grinder
-Hand-lapped the valves into their seats with a suction-cup/stick and valve lapping compound, stock valvetrain
-P06 ECU that I chipped/converted with a Xenocron kit, tuned by J. Mills at DG in NC
-Y8 intake, ported with a die grinder to match a GSR TB
-Z6 exhaust mani to a test pipe and a stock GSR exhaust

We measured nothing, just assembled it with a torque wrench and fired it up. It runs great, doesn't smoke or leak, and mated to an EX tranny in a gutted EG 4-door, it pulls hard for what it is. I've been driving it for a few weeks, put several hundred miles and a couple days of autocrossing on it, and it's going to its first endurance race this weekend.


Here's the dyno; the two lines are with/without the air filter, which is a filthy used APC conical on a homemade exhaust-bend short-ram intake. It made 129.2 with the air filter at one point, so we probably could have topped 130 if we wanted to, but the tuner tweaked it for torque delivery, which is what I want for road course racing, so the torque line got better but we lost a little top end. I'll take it:

 

I like this, a true cinderella story of sorts.