Just finished the build of my new race engine and looking for some advice on engine break in. (not to make it sound like *I* did anything, haha... Tom Lucito of "Lucitos" and Mark Hughes did all the work and I appreciate them greatly!)

Anyhow, I looked in search and found this thread from the All Motor forum:
https://honda-tech.com/zerothread?id=862940

What do you guys think? I know there are some experienced race engine builders here. Stiffler (RoadRaceJunkie) basically told me to do this (the up/down RPM deal over several passes) but said I should do it on the track and not on a dyno to get all the real world loads on the car and engine. I was going to take it to the track tomorrow but just found out they cancelled their test and tune so that pretty much screwed my plans for that. Now I'm trying to scramble to make plans to go to a dyno tomorrow. Seems like a lot of people in the thread above are saying you can break in on a dyno just fine, and that gives you the opportunity to tune too. Which leads to the next question, if it's okay to break-in on the dyno should the break in procedure be done before or after tuning the AF?

BTW, the dyno in question is a Dyno Jet and not a Mustang. There is one in the area actually, but that's another story.

thanks guys

 

What I did, per my engine builder's recommendations:
Use full throttle to 70% of max operating RPM. Variable load and High load, for example I did many 4th gear full throttle 2k-5.5k 4th gear pulls on a motor that would see 8k max. The cruise at 70 mph on the freeway isn't ideal. You want as much air in the combustion chamber as possible. Changed oil after first 30 minutes of run time. Every 200 miles until 1000 miles. Used dino oil to 1k and now Redline. Doesn't burn, doesn't smoke. 8k on the motor now.

 

Thanks for the post. I was wondering about this too since I'm in roughly the same boat. My machinist said "break it in like you're gonna use it.," but I don't know about that philosphy. I don't really like the idea of getting out and revving hard without any wear in period for the newly bored cyl walls and new rings and bearings and stuff. I think if I can get the motor in and running with some time left before the race weekend, I'll try to put a few street miles on it (by street I mean on a non-public road here at work that is completely closed off to traffic on the weekends - just to avoid the flames ). If that doesn't pan out, maybe I'll have to do HPDE Saturday and race group Sunday to break in the motor a little before just throwing it out on the track in a race.

- Scott

 

I'll be breaking in my new engine the hard way. Just be sure to have the AF's tuned immediately when you first start it up. I hear that's the number one way to ruin a good build. Metal expands and our engines were designed to work within a certain temperature range so this makes complete sense.


The idea about breaking in the engine hard has to do with the rings seating properly. You want them to seat under high load conditions. The pressure causes the rings to exert proper force on the cylinder walls to create a good seal. I don't think this means you have to rip it up to 9k right away but some good pulls in the high gears should do the trick.

This is what I've been told and read on a few sites. Makes sense to me. Someone please feel free to correct anything I've stated.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ActiveAero &raquo;</TD></TR><TR><TD CLASS="quote">The idea about breaking in the engine hard has to do with the rings seating properly. You want them to seat under high load conditions. The pressure causes the rings to exert proper force on the cylinder walls to create a good seal. I don't think this means you have to rip it up to 9k right away but some good pulls in the high gears should do the trick.</TD></TR></TABLE>

What he said. Seriously, this is nearly exactly what I was told. Low load high RPM wouldn't be good.

 

thanks guys!

 

If you go to http://www.importbuilders.com and search around, they have some good break-in tips.