Thoughts on breaking in a new engine
 

Well after a horrible last season I opted to repower. Thankfully all work is now done and as of today it's even paid for :) Here's what I've found and/or have been told about engine breakin - No quick starts, while underway alternate the engine RPM's, change the oil after 10hrs and don't run it wide open for any period of time for the first 20hrs.

Oh it's a 99 7.4 MPI in a z272

Sound about right?

sounds about perfect to me....

I agree, sounds right!

Same as I've always heard too. Although I've NEVER been able to stay off the WOT for a few seconds. Gotta see what she'll do, right?

Thanks all! I am using regular oil for the break in, and yes it will be a little hard to hold the throttle back :)

Don't be afraid of opening it up once you've got it up to temperature. More and more the research has shown that running a new engine hard for brief periods during break in is actually better than babying it the entire time. Short periods of hard acceleration are thought to be the best method of seating the rings.

well he did say to 'alternate the engine RPMs' and only to not run it at WOT for any length of time so short bursts shouldn't hurt it at all and as Z202 says should help seat the rings. My understanding was always to simply not run it at high rpms for more that a few (read 30 or so) seconds. Once you get thru the break-in period then you can GIVE 'ER HELL! :yes_grin:

i would not run it anymore than 1/2 to 3/4 idle for a couple hours. I would try to set it at 2000-2500 rpms and let run. The purpose of this is to seat the rings. It is quite possible if you had this done at your dealer it was already been done.