Good day all! I will be wrapping up a rebuild here in the next few days, was just wondering if there is anything special to breaking in a motor with the 268 cam? Along with any advice to breaking in a motor in general? Thanks!

I bought a new truck some years ago and broke it in basically in one trip. I drove it 2500 miles straight on a trip from Michigan to California. I only stopped for gas and food. It basically never cooled off. I varied my speed from 50 to 75, never staying at any one speed for very long. I drove that truck for 15 years, it never burned any oil and I sold it with 180K running like a top. So, bottom line, don't run it hard for 3k, don't even think about getting on it hard, especially when not warmed up. And, finally, don't run synthetic oil until you have at least 25k.

Just wondering, whats so bad about running synthetic in a new motor?

when u buy new trucks they tell you not to take it over 65mph for the first 1,000 miles.

I def wouldn't romp on the throttle for awhile either. Easy take-offs, low rpms, etc for the first 1000-2000mi.

I'm not sure about oil changes but you may want to be more frequent @ first too. I'd probably be paranoid and change @ 1k then 2k/3k again. then start the 3k cycle.
That's just me though, I'm paranoid about changing fluids

http://www.ntnoa.org/enginebreakin.htm

has some good advice

there is still some controversy over running hard(methodically) and taking it easy on the initial run on the motor for seating the rings. one point against is modern machining practices and tolerances dont leave much material that has to be removed to seat the rings. im 5k into my rebuild, used a 268 cam with the OS valves and an EB engine kit for mine. ran it at 2500 rpm for about 15 min(AFTER warming it up), allowed it to cool overnight because it was midnight and my wife was quite angry at this point.<img src="/forums/images/graemlins/rolleyes.gif" alt="" /> next day i changed the oil(used 30wt for the first pass) then did it again. this is to break in the cam first. i believe i used 30wt for the first 1000 miles as well. no syn, just reg oil. i took her out and in 2nd and 3rd gear ran it at full throttle from 2000 to about 4000 rpm and allowed engine compression to slow it down to 2000 again. did this about 4-5 times, then drove it easy for the next 3000 miles, varying speed and not taking it over 55mph, which wasnt too hard for my 6 mile daily commute. after the initial cam-pass oil change and the next one at 1000, i went to the normal 3k change, and after 3k ive started to run syn oil, no probs at all. the biggest thing is in these first couple runs, let it warm up completely first! no matter the vehicle or the miles, i never drive it hard until its completely warmed up. just my 2 cents, hope it helps