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How to break in rebuilt motor?

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Old 12-07-2006 | 09:43 PM
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Default How to break in rebuilt motor?

Well, it has finally come down to the wire and I realized that I wasnt completely sure how I was going to go about breaking in my rebuilt engine. My plan was to start it on cheapo oil and idle it for maybe 30 minutes and change to some moble 1 dyno oil and then go out and drive it for a few hours up to 5k rpm and medium load and no lugging of course.

Sound good? if not, how would you do it?

-ryan
Old 12-07-2006 | 10:09 PM
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There are alot of myths and legends about breaking in rings, etc. Just make sure that all your bearings have plenty of grease on them for the initial turn over. I personally use dyno oil during the entire break in. I start the car and let it idle for about 10 minutes to get the oil to operating tempurature and to let it wash out all the moly grease. Then you change the oil and the filter. Then take it for a drive never going above 3krpm. Do some 3rd or 4th gear pulls from very low speeds, slowly building up speed to 3k rpms. Do that about 10 times. Then change th oil and filter again. After that you should be good to go. Then I just change the oil every 500 miles for the first 2000 miles to make sure I get out all the microshavings. I switch to synthetic after those 2000 miles.

In all honesty, the engine is broken in with in the first couple thousand of revolutions. The rest of it is just to get out any "pollutants". I've built 3 ls/vtec motors in my honda days all using that method. All of them still work fine.

Brian

EDIT: Oh ya, you have like triple checked your bearing clearances right? Those are probably THE most crucial thing to not mess up.
Old 12-07-2006 | 11:38 PM
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all i will say is dont use synthetic for a while. maybe two oil changes. i dont think synthetic will even allow rings to seat
Old 12-07-2006 | 11:48 PM
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In the 2 motors that I have rebuilt for myself, I have used synthetic oil for the time that I have driven the cars. One of the biggest things that I was taught is take it to 2000 rpms for 5 mins, and go up 500 rpm's until you reach 60% of the intended redline. Stay at this redline until you hit 500 miles on the motor, then the redline goes up 10-20% every 500 miles. I have never seen any difference in using synthetic and dino during a break in. Change the oil often during this time because the bearings are breaking in during this time and will not be happy for a while. I use royal purple and love the stuff, your choice though.
Old 12-08-2006 | 12:12 AM
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I like what boostinsteve suggests, but insist upon using conventional oil for the first 5-10k miles.
Old 12-08-2006 | 12:22 AM
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backing out of the driveway not good enough for you guys?
Old 12-08-2006 | 12:43 AM
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Originally Posted by braineack
backing out of the driveway not good enough for you guys?
Honestly it doesnt take much more than that. The first minutes of operation are the most critical. After that its just icing on the cake.
Old 12-08-2006 | 12:45 AM
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Im not 100% sure but i heard that you are suposta go through your rev band... not like a bat out of hell but slowly so the rings set... again just heard through the grapevine but personally id go BoostinSteeve's route but with Non-Snyth
Old 12-08-2006 | 01:02 AM
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Im just gonna fire it up, full throttle it down the street and be done with it.


just kidding.

pulled the motor tonight btw:

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Old 12-08-2006 | 01:10 AM
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That is what that way does, it lets the rings break in a little slower. Just for the record, I tore apart my 1st engine at 10k miles, and even though I used the synthetic, the bearings looked immaculate still. I would use dino though because it is cheaper, and there really is no difference for the first miles. My problem is just like braineak was saying, I am way too impatient though. The first 20 minutes of the engine being started are the most critical, try your best to not boost the engine for a while if you are going to have the turbo on during the break in period, especially with this cheap oil, coking is bad for turbo.
Old 12-08-2006 | 12:14 PM
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yea i just laid off the boost untill about 500 mile were on the motor. took about 5k miles for my compression to be stop going up, so i am guessing that would be fully broken in. power got better and better till i got it to about 5k miles too. kinda makes sense. yea its very hard to hold back though.
Old 12-08-2006 | 12:35 PM
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Originally Posted by akaryrye
Im just gonna fire it up, full throttle it down the street and be done with it.


just kidding.

pulled the motor tonight btw:
I see that you use the same, high priced, transmission jack as I do.:gay:
Old 12-08-2006 | 12:43 PM
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Went back and looked.
Old 12-10-2006 | 01:11 AM
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FM suggests something like a few (three?) runs to 6000 or so and then let off the gas and coast (changing the pressure/vac on the engine). Engine should be fully broken in during the first couple of minutes.

Also, if you go buy a new Viper it will come with an engine full of synth not dino.

Note that I don't have a damn clue what I am talking about - only repeating what I have heard. My new Toyota Tacoma didn't say anything about changing the oil after 500 miles or anything. I ran the synth that was in it at 0 miles up to 5000 and then changed it. Didn't do anything special EXCEPT a few full vac runs like FM suggested and I bedded in the brakes a few times. That's it and I plan on getting 250K miles out of my truck (I'll report back later in a "few" years and let you guys know how it went).
Old 12-10-2006 | 08:59 AM
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I thought it was easier to pull the engine with the tranny still attached.
Old 12-10-2006 | 03:46 PM
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one thing to remember considering "synth" oil in cars for break in is shocking...Mobile1 is now a "group III" oil, so its not really a synth anymore.

For the pro-turbo ls1 race car motors, my father always runs cheap *** $.99 oil for 15 minutes with the wheels off the ground and a 50% max rpm hold for a few seconds at a time, then conventional penzoil for 5 hours on the engine dyno for break in...then they throw royal purple in and tune the motors.
Old 12-11-2006 | 01:24 PM
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On my built 1.6 I used to have, I just drove it out of boost up to about 6500 a few times. Maybe on a mile loop. Then I was in boost and happy. No oil consumption with Ross pistons and rower rods. My friends shop builds a lot of DSM motors. They do basically the same thing on the dyno and then do their tuning runs at full boost.

Frank
Old 12-11-2006 | 04:01 PM
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How do you hit 6500 an dnot have any boost there is no way I could do that.
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