Just got my engine running last Friday..Wondering what you guys suggest for proper break-in.. (Seating Rings) but before you answer, please read below. I know what everyone typically does, but haven't found anything that answers my question.

We started it and got to temperature then shut it off. Had it running after that for maybe 45 minutes at most. Mainly running at idle for now with a slight increase of rpm here and there to check on air/fuel ratio..but not much above 2000rp. We're nervous to bring the RPMs up too much as we do not yet have a proper tune (MS3Pro..getting dynotuned June2). Without a proper tune, I'm worried that ill go way lean/rich and have further issues. I know everyone says vary rpm to 3500, some say let it warm up then drive it like a rental.....well I can't lol.

Last time I started it, I noticed some blowby out of the breathers (each valve cover has one). Am I still safe? Am I out of luck? Should I wait until dyno time to even start it back up and hope some pulls does the trick?

Again.. cant really vary rpm to much to seat the rings as I do not have a proper / 100% safe tune yet.

Thanks!

Basically wondering what we should be doing for break-in procedure...mainly for seating the rings. We keep reading that we should be varying RPM's. Well.. we're kind of nervous to do that just yet since we arent 100% sure of the current tune/fuel tables. We have it tuned to idle okay, but kind of nervous to vary the rpm...nt knowing if we'll go way lean/rich and possibly hurt it more! Right now after maybe 30 minutes to an hour of running (mainly idle, some rpm varying but not too high at all, maybe up to 2000 rpm from an idle of 1000). Last time we had it running, we noticed some blowby coming out of the breathers. So the main questions I'm trying to get to.. should we be doing anything different? Should we not start it at all until we bring it to you for the dyno tune? Are we out of luck/everything glazed? Or will the dyno with proper tune cary the rpms enough to fully seat / break in the rings? Thanks again! Brett @ 860-942-1869

 

Twin Turbo (eBay GT45) 1999 LQ4 6.0L
Forged internals, stock crank, LS9 cam

 

I am not sure about the tune question. But as for breaking in engines, on all of our race motors we build them, start them to make sure nothing leaks, set the timing and head to the track. After the first practice session on a stock car engine or the first couple of passes, we check and change the oil. We break them in the same way we race them. Wide open. Never had any issues and most really good engine builders will tell you to just run it. Even our drag engines making over 1000hp NA from Reher-Morrison because they told us to. If its a street car, get it tuned and drive it normal for about 500 miles then change the oil.

 

Drive it like you stole it.

 

I ran Joe Gibbs BR oil, took the car out ran it up to 4-5 k RPM nice and slow and let it decelerate hard in the same gear. Put about 10 miles on the new motor and a few heat cycles and then let the tuner have at it. Made about 515 hp on the first pull. Changed the brake in oil at 300 miles and have been beating on it since. Don't be scared... Just don't go into boost and the stock tune should be fine to run for a short drive.

 

That's a great suggestion for a boosted engine on the stock tune.

 

I started my car and let it idle a few time to check for leaks, then took it to my tuner, swapped injectors and broke it in on the dyno.

 

Yea, my thoughts too. Get the tune and then go Ricky Bobby on its ***.