The "break in" process for an air cooled engine has any many explanations as there are actual air cooled engines. I am always listening for those who have actually done it, and succeeded, so if you have, I would like to hear from you.
A brief synopsis: Just did a 'top end' rebuild of a Type IV engine in my vanagon. All I really did was replace the pistons/rings/cylinders with all new parts, and installed rebuilt heads. Nothing fancy, and why I only did that, is a topic for another time if anyone really wants to know.
I fired it up, ran it at about 2500rpm for 20 minutes, even tho the crank and cam/lifters were not new, but simply left alone from the original motor. Didn't split the case. Just a simple, "get it back on the road with fingers crossed till I am rich enough to do it up all the way, perfect"
The method of seating the rings eludes me, and the reason for my asking is the very small window of time I get from the state with a temp registration to break it it, and get it past the emissions tests. No catalytic, no EGR system, so not a big window for failure and adjustments. Until one cylinder failed, it never had a problem with the emissions numbers, sans the cat and egr.
So, it sits in the driveway, starts and runs okay, and is ready for the big road effort, so I seek wisdom as to how long I am to run up and down the hills and valleys, going in higher gears, to 55, and backing down to 25, loading and unloading the rings in the cylinders before I can say that part is finished, and I may have a chance of passing an emissions test.
How many miles of this kind of "load it down, introduce the rings to the cylinders" driving is needed? Can I do it in a day of several hours? 50 miles?? Takes days and days and hundreds of miles?
No lack of long grades and hills and valleys, but lack of time to get it done is what has me paused to think. I have read a lot of on-line writeups about it, and none agree, and none are very specific as to how long this process should take.
Of course, I will take good care of it after this process, and not do extended driving at one speed on the freeway, etc, but the goal is to get it broke in, and have a chance to pass the emissions test, so if you have done it, or are a real expert and want to chime in with your opinion, that is why I am here. Just want to get to a point where I can feel pretty safe in saying that the rings/cylinders are broken in together, and move on to enjoying my van once more.
Thank you for reading all of this. I am grateful for real life experience, and advice.