Engine Start-up & Break-in Information
2) Crank for 10 seconds at a time, once per minute, at least 3 times, to prime the oil system and build oil pressure before startup. You can usually see 20-30psi of oil pressure during cranking.
3) Inject some oil into the lower plug holes of each chamber to help build compression for startup. Fresh rebuilds with old housings are very low compression initially.
4) Make preparations to idle the engine up before startup. A rebuild will not even consider idling normally for the first few hours. Use the hard idle set screw(on throttle body by linkages, 8mm locknut with flathead setscrew inside, covered by factory jb weld) to adjust the throttle somewhat open at idle, a few turns are necessary. You want the rebuild to idle at around 1500rpm for the first day or more. IF you don't do this ahead of time, and you're by yourself, youll be stuck inside the car holding the gas instead of outside checking for leaks and such, and if you stop the engine it'll be hard to get started again.
5) A battery charger or external jump(another car) is sometimes helpful in starting a rebuild, as old or partially discharged batteries sometimes lack the strength to really kick over an engine and build enough compression to start. A strong charge is a must here.
6) Be prepared for smoke…there is assembly lube in the engine, which will be burned out in the form of smoke. Expect this to get into your exhaust and smoke can remain for up to 8 hours afterwards until it is all burned out slowly.
7) Be prepared to watch for leaks…oil lines, coolant hoses, gaskets, and other connections should be examined for leaks. Youll also want to keep an eye on the gauges…oil pressure, water temperature, voltage, etc.
8) Once it is running and youre satisfied everything is stable, set the idle to around 1500rpm and let it be. Since compression is constantly changing, there isn't much use in adjusting and readjusting idle and TPS settings until breakin is almost complete, as the settings will change almost daily. Right now, the more you can drive it, the better. It is very helpful for the first few days even to just let it idle in the driveway all day.
9) Breakin should be completed as follows.Keep rpms under 4000, oil changes at 500 and 2000 miles, and no boost above atmospheric(turbo models).
10) Great improvements in starting, idle quality and overall smoothness/power will begin occurring immediately, but most improvement will be reached by 1500 miles, at which time you can gradually increase rpm and boost. By the time the engine reaches 2000 miles, it is basically broken in and can be treated as you wish within reason.