Start-up after rebuild

[dlr308]

Big day today after 3.0 to 3.2ss rebuild on a 1979 911sc.
Engine in a couple of days ago - that was a bit of a chore as a first timer. Took me about 5 hours of in and out - forgetting to hook up oil breather pipes, etc! Ripped a fitting off the oil line between the thermostat and crossover pipe - but two new oil lines to the thermostat later and that is good.
Cranked the engine without fuel pump relay and spark plugs out today - green oil light went out pretty quickly. Then some gas, plugs and relay in and after a bit of coaxing it started up....amazing. Have new cams and rockers so 20 minute break-in and then an oil change. Was a little rough - have to do the ignition timing tomorrow - but it's close. Hope the elation is not too short-lived, as I've still got to get out and drive. Was a fun job to take my mind off work and COVID the last few months.
A BIG THANK-YOU to many on this forum who helped when I got stuck.

[brighton911]

Congrats! Quite the feeling of accomplishment from doing it yourself and hearing the results on startup. Don't baby it during break in. No steady speeds or extended high RPM's for the first 300 - 500 miles and you should be good.

[lvporschepilot]

Congrats! Get those rings seated now, then change the oil. It's an accomplishment, be happy

[911 SLANT]

How many miles should breakin oil have before changing? I have a fresh rebuilt 2.8 that I need to drive for break in. How do you know if all cylinder rings seated? Does it really only take 20 min for breakin?

[lvporschepilot]

Some guys use break-in oil, I just use a standard 20w50 non synthetic and get it really hot, then vary loads and decelerate in gear. Porsche's standard in the day was to run the engine in 10 minute increments at certain rpm with large throttle openings, I want to say the test was almost an hour each engine. The way I've been breaking in Ferrari and Porsche motors is as follows:

warm up engine while driving with low loads, do not warm up static as the engine needs to have load. after the standard 20 minute camshaft break in (which is ok to do static), get light load on the engine. once oil temp is up to at least 180F, use 2nd gear to make 50-70% throttle pulls from around 2000rpm - 5000rpm, decelerating in gear back to 2k or 2.5k ish, rinse repeat 7-10x. At this time check for leaks. If all is well get on the freeway, continuing to vary rpm, increase load a bit more while varying rpm and continuing to decel in gear. Get to 100% throttle and decel a good bit. After 100 miles check how it is idling. It should be idling better than when it first started as the rings should be seated by now. If you have carbs or individual throttle bodies, you should be able to adjust and balance the flow which should be different then when they were first adjusted before driving, again because the rings should be seated by now. At this time I change the oil, but stick with 20w50 for at least the first 400-500 miles, then swap to synthetic. Changes after the first 100 miles following this recipe is nominal, but know that nikasil liners or millenium tech liners can take longer to break in completely. Anything pre 80s Ferrari is all iron liner and they break in very quickly, unless the top piston ring is chrome, in which case they take a while.