426 c.i. engine was rebuilt a couple of years ago and only has about 250 miles on it - prior owner sold it to me with

"BRAD PENN® PENN-GRADE 1® BREAK-IN OIL, an SAE 30 mono-grade oil formulated specifically to meet the critical lubrication needs of new engines during break-in while allowing proper seating of rings and component ‘run-in’."

Questions:

1. how long do you have to use break in oil until the engine is broken in?

2. should you change it to a new fill of break in oil during that period?

3. do the extra break in additives harm the engine if you use it longer than you need to?

thanks!

(1) after the 25 minute cam breakin (2) After cam breakin change to a good high zinc oil, Bradd Penn or other brand (3) Likely not but the breakin oil is probably more $$$ & ain't needed after breakin & definitely should be changed after the 25 minute breakin but you definitely need a high zinc oil from there on. Read "breakin secrets" at www.mototuneusa.com (10 minute read). Excellent info on ring breakin in which if done properly will be done in the 25 minutes cam breakin period & is likely done before the cam is finished & after that there's no part of the eng that "breaks in".

thanks Robert

Anytime bro!

by the way, that is some website over there at mototune...who is that guy?

I'm not sure who he is as I am not into bikes & what happened was that someone just put me on to that article & it impressed me as gospel. The bike cam stuff dont apply to us with flat tappet cam/lifter setups but the ring breakin part makes real good sense

The mototuneusa recommendation does have some good info and while he does say for all 4-stroke engines, we still have to be clear his expertise is modern motorcycle engines and not 1960s V8 engines. Namely, we need to be careful to follow the recommendations of the cam maker.

Also, good Break-In oil designed for engines will have no friction modifier additives which will further expedite piston ring seal. This will complement our efforts in addition to any break-in “secrets” we may utilize. In addition, good Break-In oil for our applications will have lots of zinc to prevent cam failure. In the grand scheme of things we can get good Break-In oil to do the job for about $60 dollars. Hopefully that’s not going to break the bank after we just spent thousands of dollars and many man hours putting together a nice performance engine.

Another thing to consider is that our V8 engines don’t share a common reservoir with the transmission like many motorcycles do, so we don’t have to be concerned with cross contamination with the transmission. Further, if we are using a good oil filter, particularly a modern technology micro-glass oil filter, the harmful break-in contaminates are being filtered out of the oil to a very fine degree. In that case, one may consider leaving the Break-In oil in longer than an initial 30-minutes. By contrast, one recommendation states the break-in period should not exceed 1000-miles. So really, the initial break-in fill might as well be drained out anywhere between 30-minutes of run time to 1000-miles. It's up to you where your comfort level is.

Anthony - very useful info - thanks