My brother was reading an article by a certain engine builder whose name cannot be recalled that listed his break in procedure after a new engine is built:
Strap car to dyno and set as free inertia
Start engine and immediately engage drivetrain
go from first until your 1:1 gear at 10% throttle to 45% before your redline
with car still in 1:1 ratio gear let drivetrain stop the rollers w/out engaging dyno drum breaks
shut engine off and let cool for approx ~10min
Start car and repeat process this time at ~70% throttle and between 45% and 100% of your redline
again while gear engaged let drivetrain coast to idle w/out drum breaks
shut engine off and let cool again for 10min
start engine and repeat again this time at 100% throttle to 100% redline and repeat coasting to idle procedure
Change oil and it is "officially" broken in.

His reasoning is that piston rings are very sharp when new and it is best to take advantage of them being able to seat in the cylinders quickly.
He stated with easy break ins the rings become dull and it takes a much longer time for them to seat properly or even correctly overall.
Conventional engine oil should be used for this instead of synthetic.

Any opinions?

 

If it works I am all for breaking in your motor in a day. Just a side note, I have a friend who is a real old school corvette guy. He said he always broke in his cars by running them to redline under load, i.e. on the road, with no free revving, and then he lets that car coast back down to a stop. I don't know if it is quite the same as what you described and also i'm pretty sure the rings in the corvettes in the sixties were high in chromium, and therefore very hard. Don't really know if any of this applies, i'm just a youngin'

 

http://badasscars.com/techtips.html#Anchor20

You ought to read the breakin procedure this guy suggests as well.

 

I think the biggest reason for using a dyno is so the accelleration can be controlled. Where I live there's just no chance of doing something like this w/out running into traffic or lights or cops.
I'm all for that reasoning and logic.

 

Thats some good reading!

 

Yeah I should have mentioned that when this guy was breaking in his new motors they were current model year C-2 corvettes. Rural North Carolina in the 60's wasn't exactly "crowded."

 

My break in..

After putting engine in car, make sure everything is hooked up correctly. start car. fix all leaks, etc. Open nitrous bottle. Go out on straight road. Have fun


worked for me

 

Check out this website http://mototuneusa.com/break_in_secrets.htm I used his technique on my 383 when I first fired it up. I ran it for about 20 minutes, setting the fuel pressure regulator, the TPS, and bleeding the cooling system. Then I changed the oil and filter. Next, I went to a deserted road near my house and ran it up to redline (6200 rpm on my stroker) about 15 times in 2nd gear (didn't want to go too fast) letting it back down and cool for a few minutes in between each run. Went back home, changed oil and filter again, break in complete. The engine now has about 700 miles on it and runs perfect.

 

Anything you SHOULDN'T do?

 

I'm trying to get a consensus from others whether redlining it is bad on new valve springs or not. I read on one of the cam manufacturer sites that the springs need to be heat cycled a few times before really working them or it ruins them to some degree. Has anybody had experience with this aspect of break-in?

 

We can skip the cam breakin since we have roller lifters.

 

I thought about that, but I figured that I let them heat up for 20 minutes or so when I was setting the fuel pressure, TPS and bleeding the cooling system.
You can alway change valve springs if you need to, but you only have one chance to seat the rings.