MikeGyver

I finally got my turbo'd 383 together and running and it's break-in time.
It seems Everybody swears by a different break-in procedure. Lets hear yours. What do you do, and more importantly, WHY?

Injuneer

One hour on an engine dyno, under varying load (moderate) and varying RPM (low to moderate). Change oil, filter. Inspect/adjust everything. Begin dyno tuning ~40 pulls (NA, NA+1-stage N2O, NA+2-stage N2O) culminating in several 750HP+ nitrous pulls.

MikeGyver

Sounds pretty similar to what I've done minus the dyno part. I've got maybe an hour of runtime on it and the rings havent sealed yet because its only pulling 11-12" of vac at idle and blowby is presurizing the crankcase under boost.

WS6 TA

What it's going to take for the rings to seat depends on what rings you used and in what block. Otherwise, unless you're still running a flat tappet cam it's just a matter off getting all the assembly gunk and any dirt that was still in there washed out, drained and new oil put in, and it's ready to run. Hopefully the first 2 parts are enough time to make sure nothing is assembled wrong/needs to be torn down and redone.

arnie

I trust the engine is equipped with a roller cam, which along with other positive reasons as well, was a God send for the break-in procedure. The reason being, what is the most productive/effective means to seat the rings can be very damaging to a flat tappet cam/lifters, and visa versa. Meaning, what is the most productive means to break in a flat tappet cam is a poor way to seat the rings. A roller needs no break-in per sa. With a flat tappet cam the super stickler (what does the Sargento cheese commercial call him?) would break in the rings with a used cam and install the good/new cam after the ring/wall mating procedure.

Other than proper assembly, there are compounds that can be applied to the cylinder walls at assembly that will hasten the seating/mating of the wall and ring surfaces. Obviously, in your case it is too late.

The engine dyno suggestion means of break-in is better as it is more controlled except that a great majority of us do not have one in our garages or ready access to one, so that idea can be legitimately and logistically questioned. However, the principle would be similar. BTW, I am also a firm believer in breaking in an engine sans the FI or nitrous. Do the break-in without any 'baggage' attached.

The general idea is not to baby it. Be aggressive when breaking it in. An effective old school method is to 'cycle' the engine revs. Starting with 2500 or 3K and working up in 500RPM increments, run it up to the designated RPM and let off back to near idle. This is one cycle. Do this for 10 cycles before incrementing up the designated 500RPM until you reach your intended max RPM. Then change the oil. With fresh oil put on maybe a couple hundred miles and change oil once more. Yes, keep an eye or two out for any unusual gauge readings along the way.