best way to break in new rebuilt engine

[paduster]

this is my question. i am rebuilding my motor while i wait to get a probationary license. this rebuild i am doing will mostly take a while while i paint and and rebuild my 3.0. if you don't know i am building a 10:1 motor with maybe some head work if i can afford it cause they shouldn't need machined i just want to do some porting work there. i will be breaking it in on a stock 5 speed computer. i have the chrome rings from summit and the king bearings Joe used.

so what would you do to break in this motor?

[Sundance 6g72]

your opening a big can of worms.

im a big fan of driving it like you stole it

http://www.mototuneusa.com/break_in_secrets.htm


thats how i did my motor and it pulls like it used too. i have not checked my compression with a comp. tester though!

Baker Engineering also told me to not idle my engine for long, and to get it out on the road and give it some good load.


Things i made sure to do were

- high rpm HIGH LOAD
- high rpm low load (off gas but still high rpm)

[turbovanman²]

Yep, drive it like you stole it. I also follow the Hastings way, 2nd or 3rd gear, WOT from 20-50 mph, then chop the gas, repeat a 15 or so times, then change the oil and filter, continue to beat on it.

[contraption22]

If you have a good bore finish, all I would do is prime the oil pump if possible, (don't know much about 3.0) start her up. Let her get up to normal operating temperature. Shut her down and let it cool. Repeat. Drain oil and fill fresh oil.

Done.

Your engine has all the break in it needs, assuming everything else was done right. And if it wasn't, no amount of voodoo or old-wive's-tale break-in proceedures are going to change anything.

[turbovanman²]

^^^How do you figure that?

Idling doesn't press the rings against the bore, if you knew how rings work, you wouldn't let it idle. Phone Hastings with your advice, they'd shudder.

[Sundance 6g72]

boosted motors love a hard break in. the boost forces the rings against the cyl walls. with an NA motor, you cant do that. You have to give it 100% throttle and keep it at ambient pressure as long as you can through the rev range. i dont belive in just letting it idle.. if you read my link i posted, you will SEE the difference between a nice break in and a drive it like you stole it break in. tried and true.

[rib256]

Rebuilt 2.2 5 spd. I did many 2nd or third gear low boost runs. Up in rpm, drop the gas, up in rpm, drop the gas. Find a nice stretch of road where you can do it without attracting attention. Motor runs like a champ and made enough horsepower and torque to nuke an A555. In other words, Turbovanman +1

[trannybuster]

dont encourage him! ^^

[Ondonti]

http://www.mototuneusa.com/break_in_secrets.htm

That is the correct way. Read any engine building book and its basically the same procedure. Watch any engine dyno breakin procedure. Same thing.

Idling the motor beyond warmup is how you glaze cylinders.
I wouldn't bother breaking in a motor when you should not be driving right now. Just wait.

[Sundance 6g72]

thats the link i posted :P

[contraption22]

^^^How do you figure that?

Idling doesn't press the rings against the bore, if you knew how rings work, you wouldn't let it idle. Phone Hastings with your advice, they'd shudder.

Really? Your engines don't have any cylinder pressure at idle? Mine always have.

I will give you two reasons I won't call Hastings and waste their time.

1. I don't use their products.

2. I've never had a problem with cylinder seal using my method.

[Pat]

My method so far has been to start it, make sure nothing leaks, drive it around the block to make sure nothing falls off, change oil and head to the track. Haven't had any issues yet.

[contraption22]

My method so far has been to start it, make sure nothing leaks, drive it around the block to make sure nothing falls off, change oil and head to the track. Haven't had any issues yet.

Hastings would shudder!

[RoadWarrior222]

It's not just about seal though, it's about best seal plus least friction. Friction makes your motor hot and robs power, if you glaze it off tight, sure it still runs, but you're losing the last 10HP you could have had, and are you gonna relate the 60,000 mile ring failure to your breakin or blame it on something else?

First stage, after sensible precautions of checking for leaks, and taking a breif checkout spin... knock the peaks off both sides of the cylinder... = load it both ways, 2nd gear pulls and engine brake! preferably downhill... do up to 200 miles of that, then change oil, then drive a few hundred varying speeds, not holding one rpm for long, then take it for some long highway runs, to glaze off... you should now have best seal + lowest friction + max power + best mpg.

[tryingbe]

I warmed up and did a hard break in. 0-2% on leak down test.

[Sundance 6g72]

Really? Your engines don't have any cylinder pressure at idle? Mine always have.

I will give you two reasons I won't call Hastings and waste their time.

1. I don't use their products.

2. I've never had a problem with cylinder seal using my method.

much less pressure at idle than at 10psi

maybe never had a problem but not necessarily a better ring seal.

[turbovanman²]

Hastings would shudder!

So Pat actually drove it, while you don't, hmmmmmmm, I'd shudder too.

[contraption22]

So Pat actually drove it, while you don't, hmmmmmmm, I'd shudder too.

Really? You think I break in an engine, then pull it out use it as an end table?

All I am saying is that the only special procedure needed are those two heat cycles before the first oil change. After that it's ready to beat on. No more "break in" needed.

To say you need to drive the car a certain way for hundreds of miles to break it in... that's just nuts. Perhaps it was true decades ago when machining tolerances and piston rings aren't what they are now, but not any more.

[RoadWarrior222]

not any more for tolerances and rings as they are TODAY, we're dealing with 30 year old tech.

[contraption22]

not any more for tolerances and rings as they are TODAY, we're dealing with 30 year old tech.

If your pistons, rings and bores are 30 years old, then they are probably broken in by now. Mine are fairly new.