Alright I've searched around for a break in prcedure for newly built forged engines. I just got done tearing my engine apart and putting new rings back in my forged engine since the rings never seated. What is a proper break in procedure for a newly built engine I.E. what AFR do you want to run it at, any special type of oil, and weird driving habits to observe, oil changes, etc... I'm just looking to avoid what happened before with my rings not seating in the engine because it was to rich on the AFR. Any input would be great. Also, how long do you keep a new forged low compression engine (8:5-1) out of boost?

 

I just rebuilt my engine and got some recommendations from a guy at the machine shop. Here are some of the highlights of what he told me to do...

1) Use conventional oil for the first 3k miles. Do not use synthetic or synthetic blend.
2) Use straight 30 weight oil and run the engine for 30 minutes. Drive it easy. Run the RPMs up to about 5000, but do not give it any more than half throttle. Be sure to vary the RPMs constantly and do not drive a constant speed.
3) Change the oil (and filter) after 30 minutes and switch to normal oil weight (I used 10w30). Continue to drive the car easy with varying RPMs. Do this for another 250 miles.
4) Changine the oil and filter again and gradually beat on the engine more rather than suddenly beating the **** out of it. Continue to use conventional oils until you have 3k miles on the rebuild.

 

what AFR should I run it at? My tuner said he wants to run it lean so the rings will seat. This doesn't sound right to me though!!!

 

Having the AFR too rich will wash the rings. I would shoot for something like 12.8-13.0. It doesn't need to be real lean.

As far as break in, I have heard take it easy then I have heard the 50/50 75/75 100/100 rule.

That is 50% throttle to 50% max rpm you plan to spin, then let it decel on it's own back to your starting rpm. Do that 3 times. Then 75% throttle to 75% of max RPM you plan to spin, let it decel back to starting rpm 3 times. Then 100% throttle to 100% rpm and let it decel back to the starting rpm 3 times.

 

sweet. Thanks guys. My tuner isn't givingme the best warm and fuzzy so I think I'm going to tackle that part of it myself. Only leaves one person to blame if something goes wrong, plus I'll save an assload of money.

 

Check this out.
http://www.mototuneusa.com/break_in_secrets.htm

 

I always followed more along the lines of the first response in the thread. I never beat on a fresh engine, but don't lug it around everywhere either.

After seeing that, it makes some sense, but is still a bit on the iffy side for me. I'd like to see that on Myth Busters

 

I was just gonna say what the article basically says. You need cylinder pressure to help break in those rings. Keeping the revs low is ok, as long as you aren't lugging the engine. I'd say make several low speed acceleration runs at 50% throttle from 2000-4000 rpms in a taller gear ratio. After 3-4 times, continue to increase the throttle opening and rpms. You don't necessarily need WOT and the redline to generate the cylinder pressure needed. Peak cylinder pressure should be somewhere near peak torque, or about 4800 - 5200 for most of us.