I broke my latest 408. I had a spark plug melt down and the thread broke off into the cylinder and scorged the block . Anyways, My new motor is close to being ready and I'm wondering what the majority of you guys do for break-in procedure. I've talked to some guys and some major vendors that say the best way to break it in is to heat cycle it and then throw it on the dyno. And some say that's the way to go because even nascar motors are broken in like that. But the way I look at it is nascar motors are built to last a race, not longevity. And then I've talked to other vendors about break-in and they say put at least 500-1000 miles of easy driving on it w/out going into the high rpm range. What's the consensus here? My local shop wants me to put 1,000miles on the motor and I'm fine by that. I've seen a post or two about this, but I couldn't locate it. Just wanting to get a broad range of opinions. Thanks a bunch--Andy

 

drive at various engine speeds while avoiding full throttle using mineral oil for about 600miles.

 

Id drive at variable speeds to help seat the rings for a couple hundred and throw in a few wot in the process. Every engine that is built where i work are taken for a short test drive (just to check for leaks) and then go straight to the chassis dyno.

 

1000 mi using conv. oil w/ a GM additive called E.O.S.

 

mine is also close to rebuilt...what is this about mineral oil?!? how does that work?

 

i know quite a few people that have tried this way with good luck.


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

 

i have been trying to find that article again for a LONG time now, thankyou

 

I've wandered this myself and am having a motor built right now and am still asking this questions. It seems is though the proper way to seat the rings is to do what is mentioned in the article you provided a link to. However, what does that do to the bearings and such is the question? I think it is really a "it's your car, break it in how you want to" kind of situation. All arguments probably have some merit and probably provide different results. For instance the article sited my produce a motor which has great ring seal and makes a little more power but suffers in longevity cause of pre mature bearing failure (this is just a suggestion, not factual by any means). And if you provide the motor with the nice easy 500-1000 mile deal it may be visa versa.

 

Please explain the additive, never heard of it.... Do factory cars comes with it?

 

This is how I broke in my motor. Look at most if the top engine builders for Performance Motors. They build them and put them directly on an engine dyno. I think this is why some engines run good and make decent power and sum run really good and make awsome power. Look at the "Factory Freaks", I think it has more to do with how the car was broken in.

 

IT IS AN ENGINE OIL SUPPLEMENT THAT HELPS THE BREAK IN OF RINGS AND BEARINGS. WE USE AFTER AN ENIGNE REBUILD

 

Dont know if this will do the same for a GM small block, but on the new 05' Carrera S, Porsche urges its buyers to keep it under 4200rpms for the first 2000 miles. I mean, it's a high performace street car too, and I think Porsche might know a thing or two about cars. Good luck with whatever you do.

 

with the motors nowadays a 5-10 minute intital fluctuating rpm range will seat the rings. The worst thing to do is to let it idle. After that drive it like you intend to. I've rebuilt many motors this way and never have had any problems.

 

Wow, I've never heard of that "running it hard" method before seeing that link. I wont lie, everything that guy wrote on that site really convinced me. The thought of it is still a little uneasy, but if all he said is true it makes sense. hmm.

 

Bearings do not break in...there is never any metal to metal contact with bearings. Rings do seat and they do it rather quickly (not 500 miles) and the more heat the better for seating rings (to a point lets not get ridiculous).

Here is how I break all my motors in (not that I am some expert engine builder but it works for me)

1. Prime the oil system
2. Fire it up and hold it at high idle 1500-2000 rpms (old school method for flat tappet cams but still works to keep the fuel mix a little leaner)
3. Bring it up to full operating tempuratures then shut if off (10-15 minutes)
4. Let it cool down and retorque everything...heads, rockers, manifold.
5. Repeat step 2, 3 and 4 but vary the rpms this time.
6. Change the oil
7. Hammer the living **** out of it for about 20 miles
8. Change the oil
9. Have fun
10. Drink a beer (or six) to celebrate

I have done this on regular SBCs as well as LS1s and everytime I get great compression that is even across all 8 and awesome power.

 

I'm with 01-6spdz i am always run 5-10 min at various rpms and then go and drive it like it will be driven . i have never had a prob with any of the motors that i built.

 

i start it up and listen for knocks

then drive it for 100 miles or so

then drain oil and drive it

 

Start up
warm up
cool down
change oil
beat the hell out of it/dyno/whatever


and bearings don't need a break in... if the bearing is touching metal, something is wrong..

 

I drove mine hard, and varied the rpm's a lot. Changed the oil after a week of driving and then after a month again. It's doing great.
My dad taught me that if you break your motor in like a *****, it will always act like a *****.
He's always had good luck doing it that way.
This was my first time doing it, but so far so good... Got about 4k on it now.

 

if the manufacturers said to run the **** out of it people would be bouncing them off the rev limiters coming out of the parking lot and blowing them up left and right. their main concern is to make it last past the warranty, not to make 100% maximum power.

the key point i see in the mototune way is to understand the difference between keeping a load on the engine-heavy throttle, high gears, not just revving the crap out of it.

and i'm guessing that most cars have a few miles on the dyno before they ever leave the factory to check emissions, leaks, etc. but if you're firing it up yourself after a rebuild, then you have an advantage.