engine break in?

[stink]

Im currently rebuilding my engine and hope to have it done before IFO in march, but i was wondering what is the "right" way to break in an engine?? what im replacing is the rods, gettin the crank redone, boring the cylinder .20 over and wiseco pistons. still running the oem valvetrain and most likely computer. i am also puttin on a 70mm turbo with new front mount and goodies. any input will help so let me hear those opinions... thanks

[dbeiler]

This isn't the 1900s. Engines don't need 'breaking in'. Drive it like you normally would. Change the oil within the first hundred miles to flush out any contamination resulting from the rebuild. Take it slow, on low boost until you have verified there are no fuel, oil, or boost leaks.

[stink]

Ok i was always told on the sr that id need to keep it under 4k and like you said run low boost and change the oil.

[jr_ss]

Generate high vacuum to pull the rings out to aid in seating them to the cylinder walls. Lots of downshifting from speed. Vary engine speeds, keep it below 4k for a few hundred then slowly add more rpms. 7-10psi is fine so long as your not WOT for long period of time. There are many, but not one correct way to break in motors.

[feito]

non-detergent straight mineral oil, wide open throttle through all the gears, no high revving, downshift and let it coast in every gear while downshifting, and of course change the oil after the 1st 100 miles. Do this the soonest possible after the rebuid/overhaul.

[Croustibat]

please, not again :(

http://lowres.cartoonstock.com/miscellaneous-worms-can-tin-opening_a_can_of_worms-opening-jfa2492_low.jpg

Anyway, yes it needs a break in, but only piston rings and the hone do.

Best advice i can give you is to do what your engine builder says to do, and do not listen to any other advice from "internet experts".

You are also going to need bigger injectors, probably a bigger maf too, and a tune. Mandatory with a bigger turbo.

[stink]

please, not again :(

http://lowres.cartoonstock.com/miscellaneous-worms-can-tin-opening_a_can_of_worms-opening-jfa2492_low.jpg

Anyway, yes it needs a break in, but only piston rings and the hone do.

Best advice i can give you is to do what your engine builder says to do, and do not listen to any other advice from "internet experts".

You are also going to need bigger injectors, probably a bigger maf too, and a tune. Mandatory with a bigger turbo.

How much bigger???

[RalliartRsX]

If you are asking how much more injector you will need while slapping on a 70MM turbo, you have no business doing anything outside of the stock turbo........IMHO

As recommneded, there are a tons of methods, but the idea is you want to have the rings seal as well as possible to prevent a massive amount of blowby.

jr-ss method sounds like a good start!

[kleenS14]

I always let the motor idle for 20_30 min while confirming everything is kosher. Use basic, non synthetic motor oil, or the expensive specified break in oil. Change oil after idle cycle, then go ahead with the road test as jr_ss stated. Like a lot have stated, there are many methods of doing it, in my experience this method has worked well. Your engine builder will undoubtedly have his own methods though, and id follow that. The only truly agreed upon issue is the oil.

[Croustibat]

I can't see how vacuum helps pushing rings on cylinder walls, it is quite the opposite.

Rings seal because gases in the cylinder push the ring against the cylinder wall, either from the top of the ring on most rings, or by going behind with gapless rings. High end pistons even have holes machined directly from the top of the piston leading to the piston ring space to make it work even better.

Put vacuum there and the ring gets pulled closer to the piston, preventing seal...

theory:
http://photos.motoiq.com/MotoIQ/Project-Cars/Project-Professional-Awesome/i-MkDsSKm/0/M/24-M.jpg

side porting to get better ring seal:
http://photos.motoiq.com/MotoIQ/Project-Cars/Project-Professional-Awesome/i-G9gFhfL/0/L/4.6L3VAmourPlate1-L.jpg

vertical porting:
http://photos.motoiq.com/MotoIQ/Project-Cars/Project-Professional-Awesome/i-VpRcmP5/0/L/Gas%20Ported%20Pistons%202-L.jpg

I really can't see how high vacuum helps sealing. The way it works tell me it hurts sealing, meaning staying at idle, with high vacuum and very low gas pressure in the cylinder is BAD for sealing.

[pacotaco345]

Whoever said that this isn't the 1900s an the motor doesn't need to be broken in, ignore him. If the motor isn't being built by nissan in a fancy hermetically sealed room then dust and debris are gonna get in there, regardless of how careful the builder is. I think it's already been stated in here a couple of times but start the car, make sure everything is ok, get it hot, then dump the oil. After that just drive the car like a normal law abiding citizen for a couple hundred miles. Dump the oil again and after that you should be good to go.
Regarding high vacuum in order to get the rings to seal, I personally have no knowledge on the subject but my machine shop and the internet has always told me to do a decent amount of decel in gear for the first few hundred miles...

[240sxvaj]

when i built my KADE, i broke it in hard but nothing too crazy. lots downshifting when slowing down and oil changes left to right lol. i follow motorman break in http://www.mototuneusa.com/break_in_secrets.htm and got advice from the guy that built my kade. the guy that built my motor haven been building full race motor for 20 years and he beat it when he breaks it in. my motor is still running since i sold it and have never needed another rebuild (i still talk to the new owner) its been maybe 7 years since i got it built.

[Mikester]

Too many methods to count. Rings need to be seated different rpm ranges. Other than rings, no 'break in' required as everything else should have been very accurately measured to within some pretty stringent tolerances... Not like older V-8's where cams had to physically 'wear in' to the lifters.

If you drive it like a granny for x-miles, it will be tight at 4,000 & below... Does not account for 4000+. Needs to be ran multiple times to higher rpm ranges as well; engine breaking to as low as it gets before needing to downshift. A wise man once told me that whatever 'breaking in' is done in the first 20hrs of engine life pretty much sets the tone for the rest of its life. If the rings aren't properly worn in up in the higher ranges, there will come a point where they will never seat and there always be excess blow-by.

Croustibat said it best- Do whatever your builder says to do. Hell, have him/her do it for you- That way if anything goes wrong, it's on them.

As for keeping the rpms low for the first few hundred miles, I do that for wearing clutches in. When I had my SR built, I drove it semi-easy with a few good pulls for about 75-100mi, drained/inspected the oil, put fresh stuff in & proceeded to do several consecutive pulls/engine brakes at every 1,000rpm from 4000-8000rpm... Did this every day on a long straight road for about a week. Anything below 4,000 gets taken care by virtue of normal driving in traffic.

As stated above, use NON-DETERGENT, NON-SYNTHETIC oil. I used 10W-30; but again, use whatever your builder recommends.

Just my $.02- Take with a grain... for I am not ASE-certified and just another faceless forum dude.

Mike

[KAT-PWR]

My .02
You spent a lot of time and money building the engine. The rings need to seat properly on fresh walls, i don't find that point debatable.
My opinion is take it easy for the first few hundred miles, vary the load, maybe hit a little boost. Make sure youre engine is running properly. You installed a new motor... you redid your intercooler piping, your intake set up, maf, all lines going to the engine.
TAKE IT EASY
Take the time to listen to your motor, monitor vitals; oil pressure, vacuum, boost, oil temp, water temp, vacuum, boost leaks.
Say you start hearing knock, detonation, valve chatter, etc.
Would you rather be pegging the redline and damaging things faster?
Or would you rather be gentle, make sure all systems are in check and allow the motor to "settle"
I'd rather catch an issue while cruising gently then banging the limiter.
Change the oil to get rid of contaminants; assembly lube, metal particulate.
Then beat the ever loving shit out of your motor knowing it is ready

I know a very reputable guy who says "If its built right its fine" as he slams the limiter on a new engine.
While that is absolutely true
Say a bearing is hurt, tune is off... pounding the limiter is asking for a total rebuild, and harsh destruction.
Hear that same chatter while being nice to it, you're looking at much less work to remedy the issue.

[TheRealSy90]

I've always said break an engine in the way it's going to be used for its lifecycle. If it's a daily driver car, drive it like that, floor it a couple times here and there. If it's a race engine that will live at wot, after the intial start and warm up, change the oil and go beat the living shit out of it if everything looks good to go. Works great.

[NISR20MO]

I've always said break an engine in the way it's going to be used for its lifecycle. If it's a daily driver car, drive it like that, floor it a couple times here and there. If it's a race engine that will live at wot, after the intial start and warm up, change the oil and go beat the living shit out of it if everything looks good to go. Works great.

Agreed! Break it in for the life it will live, have some FUN.

Here is a link a friend showed me awhile back, he used this method on a new GSXR750 that he personally un-crated w/ 0 miles on it. http://www.mototuneusa.com/break_in_secrets.htm

To address comments above. Downshifting and using the engine as a brake puts a vacuum on the cylinders and scavenges the excess oil out of them since the new engine isn't fully seated/sealed yet and has more oil getting past the rings. Too much lube is not a good thing, extra oil makes it tougher to seat rings. Way I see it. If your motor is built wrong you are taking it apart anyway, have some fun.

[TheRealSy90]

Yep, basically you want that vacuum to scavenge the oil, and boost to push the rings out and seal them.

[PoorMans180SX]

Lots of opinions in here. None of them are technically "wrong", but there are a lot of myths about "breaking in" an engine.

Let me dispel some of them. I work at shop that builds LOTS of 500+whp four cylinder engines, and we have tons of machine shop experience that we use to make sure everything is spot on. We usually end up breaking new engines in on the dyno, after it's ran for 20 minutes and no boost, oil, coolant, etc leaks are found.

Break in oil: There is no need to run a break in oil, OR use non-synthetic oil for break in. You use heavier molybdenum lube on the camshafts to keep them from galling on initial startup. The rings require oil film to seal, you might as well have good oil in it.

Breaking in rings: The rings and the finish hone are what determine how the "break in" should go. Some rings are softer and need less aggressive hone to seat (OEM style). Some rings are very hard (chrome-plated like Wiseco), and require a more aggressive hone to seal properly. There should be very little blowby after the first 20min of running, especially on an OEM-spec rebuild.

RPM limits: If the bearing clearances are correct and the oil pump is functioning correctly, you won't have to worry about RPM limits when breaking in your engine. Sure, keep it conservative to make sure everything is okay, but once you're confident everything is good to go, let her rip! An engine with assembly errors will usually die within the first 50 miles. Bearing clearances inappropriate for high power levels won't show up until you reach those levels however.

Tune: Make sure your tune is spot on. You really don't want a new engine running excessively rich or lean.

Boost: There isn't really a reason to run low boost if the engine has run for 20+ minutes. The rings are seated, and the engine is fully capable of making the power it should. Sure, they'll break in a little more over the next couple hundred miles, but if they aren't by a half hour of running, they'll probably never seat fully.

[JSimpson]

I was/still somewhat am a professional racecar driver, all of the engines were $40,000-$150,000 from TRD, Cosworth, Nissan (Nissan Motorsports), and various domestics (GM, Ford, etc). What we always did and what I was instructed to do was start the car in the shop on the stands and rev it up and down through the rev range at varying throttle until the engine is up to operating temp. Checking for leaks while this is occurring. Then we would take it to the track, start them, warm up again until at operating temp. Next we would roll them out to the pits, warm up to temp, and do an "install lap" where I just ran 1 lap, clunk through all the gears, pump the brakes a bit, and would come in with the engine still running, pull the engine cover off and look for leaks/drips/sounds etc. The engine rep from whichever supplier would plug into the car and watch it run on his laptop for a few seconds and would make sure everything was A-OK. 2 Mins later we would start it and go flat out and treat it like a race motor for the next 600 miles haha.

It seems all the manufacturers used this method with very little variation. If its good enough for TRD and Cosworth, its good enough for my rice burner 240 motors haha.

[TheRealSy90]

Make sure your tune is spot on.



This is the only thing i'm worried about with my new build. Since i'm switching to a stand alone ems, i'm not going to have any sort of tune to start with. So i'm not sure how i'm going to do the initial start up, oil change, break in, and checking things over before taking it to the dyno to get tuned... Even if the ems (aem v2) has a base map of some sort to start with, nothing on the engine is stock anymore so it wouldn't really work well at all.

[JSimpson]

This is the only thing i'm worried about with my new build. Since i'm switching to a stand alone ems, i'm not going to have any sort of tune to start with. So i'm not sure how i'm going to do the initial start up, oil change, break in, and checking things over before taking it to the dyno to get tuned... Even if the ems (aem v2) has a base map of some sort to start with, nothing on the engine is stock anymore so it wouldn't really work well at all.

Those stock AEM tunes are junk. I would be shocked if the car even started. Been there, cranked and cranked that haha.

[TheRealSy90]

Those stock AEM tunes are junk. I would be shocked if the car even started. Been there, cranked and cranked that haha.

I really wasn't relying on it to run the engine anyways lol. So yeah idk how i'm going to break in the built engine unless i take it to the dyno fresh and talk them into letting me change the oil there etc. But then I risk having issues of some sort and having to pay labor whearas at home I could have fixed any issues myself if it ran :/

[PoorMans180SX]

This is the only thing i'm worried about with my new build. Since i'm switching to a stand alone ems, i'm not going to have any sort of tune to start with. So i'm not sure how i'm going to do the initial start up, oil change, break in, and checking things over before taking it to the dyno to get tuned... Even if the ems (aem v2) has a base map of some sort to start with, nothing on the engine is stock anymore so it wouldn't really work well at all.

Find someone who is willing to send you a basemap. Are you running speed density? It shouldn't be too much of an issue to get a basemap set up for that.

[TheRealSy90]

Find someone who is willing to send you a basemap. Are you running speed density? It shouldn't be too much of an issue to get a basemap set up for that.

Yeah i'll be running a map sensor and iat sensor. I'll try to see if the tuner can come up with a base map for it if possible. I kind of thought that I could take the stock redtop sr20det map the aem comes with, scale the fuel map for the injectors i'm using, and that it should start up.

[Kingtal0n]

Yeah i'll be running a map sensor and iat sensor. I'll try to see if the tuner can come up with a base map for it if possible. I kind of thought that I could take the stock redtop sr20det map the aem comes with, scale the fuel map for the injectors i'm using, and that it should start up.

I dont like this. You are better off installing a stock injector/maf/ecu and breaking the engine in like that. By the time you get a solid tune for driving the car around normal you've already washed the cylinder walls down, polluted the oil, screwed up your fresh rings etc...

[TheRealSy90]

So basically I should buy back everything I've already sold off the engine since I didn't need it anymore -_- Not to mention having to find another factory turbo setup since I'm running a top mounted 20g. Wow this sounds like a pain in the ass already. What's the point in building the engine if I have to leave it "stock" to make it run correctly.

[Rb26kouki]

I had the same issue. So I just got a ROM tune by JWT broke it in my self. My tuner for my AEM EMS wanted to charge me an extra $400 for Dyno break it on top of the $600 for a full tune.

[PoorMans180SX]

So basically I should buy back everything I've already sold off the engine since I didn't need it anymore -_- Not to mention having to find another factory turbo setup since I'm running a top mounted 20g. Wow this sounds like a pain in the ass already. What's the point in building the engine if I have to leave it "stock" to make it run correctly.

Nah dude, just get a solid basemap. Your tuner should be able to provide you a basemap for the engine if he knows what he's doing. There isn't going to be a problem unless you're running really rich (10-11.0 AFR). All you need to do is confirm no leaks and get the engine up to operating temp once. After that it's good to go on the dyno.

[TheRealSy90]

And I literally just sold my Enthalpy ROM ecu haha, wow. Idk I'm pretty confident that I can at least get it running for the initial start up and warm up to make sure nothing leaks or whatever, and then change the oil and have them just tune it from there.


Nah dude, just get a solid basemap. Your tuner should be able to provide you a basemap for the engine if he knows what he's doing. There isn't going to be a problem unless you're running really rich (10-11.0 AFR). All you need to do is confirm no leaks and get the engine up to operating temp once. After that it's good to go on the dyno.

Cool that's what I was hoping to do.

[Kingtal0n]

Nah dude, just get a solid basemap. Your tuner should be able to provide you a basemap for the engine if he knows what he's doing. There isn't going to be a problem unless you're running really rich (10-11.0 AFR). All you need to do is confirm no leaks and get the engine up to operating temp once. After that it's good to go on the dyno.

this is true. The bold is the problem though- most "tuners" do not know what they are doing. And if you make a single attempt with a single tuner... and he fails... that is it, time to rebuild again. And make another attempt.

A stock setup doesn't need a stock turbo. Just do not boost the engine (disconnect the flapper and run the car at WOT, it will only make 1-2 psi).
It takes a little bit of fundamental mechanics to see the principle. My method was only a suggestion for those without the intuition and experience to tune the engine themselves- better to rely on OEM electronics/tune than pray you found the right person. People are people.

[PoorMans180SX]

Boosting the engine is fine though...

[Kingtal0n]

Boosting the engine is fine though...

not with stock electronics and a huge turbo. He claimed he needed to re-install a stock turbo (which would be fine buts its a pita)

also you bring up an interesting thought. If this is the first time the engine is being tuned, you always start off rich and work your way lean.
So your tuner just took a freshly rebuilt engine and added an excess of fuel on purpose- exactly like he was supposed to do. You step down and watch the wideband... whats that? 10:1? Ok stop and let me pull some fuel out. Now boost again. Whats that? 10.5:1? Ok hold on, let me pull more fuel out.

you want to do that to a fresh engine? because thats how you tune boost for the first time on any engine.

[daryl337]

I can't see how vacuum helps pushing rings on cylinder walls, it is quite the opposite.

Rings seal because gases in the cylinder push the ring against the cylinder wall, either from the top of the ring on most rings, or by going behind with gapless rings. High end pistons even have holes machined directly from the top of the piston leading to the piston ring space to make it work even better.

Put vacuum there and the ring gets pulled closer to the piston, preventing seal...

theory:
http://photos.motoiq.com/MotoIQ/Project-Cars/Project-Professional-Awesome/i-MkDsSKm/0/M/24-M.jpg

side porting to get better ring seal:
http://photos.motoiq.com/MotoIQ/Project-Cars/Project-Professional-Awesome/i-G9gFhfL/0/L/4.6L3VAmourPlate1-L.jpg

vertical porting:
http://photos.motoiq.com/MotoIQ/Project-Cars/Project-Professional-Awesome/i-VpRcmP5/0/L/Gas%20Ported%20Pistons%202-L.jpg

I really can't see how high vacuum helps sealing. The way it works tell me it hurts sealing, meaning staying at idle, with high vacuum and very low gas pressure in the cylinder is BAD for sealing.



It's a combination of both.

The correct way is to hammer on the throttle on break-in under load - within 50 miles worth of run time. You should be starting the engine- and immediately (if new cams installed) bring the rpms up and hold them to ensure high oil pressure is reaching the cams to allow break in. Once no leaks have been shown and the engine is warmed up, take it out on the road with your base map and do a couple of 3/4 throttle runs in a high gear (for the load) The harsh load will force the rings outwards to generate break in wear against the hone- but the vacuum actually is equally important - as it draws fresher oil thru the rings which helps evacuate metal from rings seating against the hone. So when you run up in RPMS, then allow the engine to decel under load as well. This will cycle the oil. Get back home - turn the engine off and allow it to cool. This does not have to do with heat cycling in the sense you might have heard with old school engine builders - its more to allow the rings to shrink in size again, which will promote an even wear pattern around the bore as your rings rotate - finding their seat. You will notice oil burning and smoke in the exhaust while doing this at first - but give it like 10 runs this way and that will all be gone.



After that - finish up your tune and go buck wild.





Atleast this is how I was told how to break in rings when I worked at the machine shop.

[zombiewolf513]

For first start up, unplug the cas to prevent spark and fuel, then crank the engine 10-15 times to ensure oil has made its way around the engine, plug cas back in and crank until the car starts (might not happen immediately).

For the first 20 miles, let it get to operating temp before driving for sure, heavy throttle and rev match downshift engine braking, sorta like racing around. You want boost and vaccuum, both create ring seal. Dont hold the RPMs at the same place for the first 500 miles, work it around the revband. Oil changes at 20 miles, 250 miles, 750 miles, and 1500 miles starting with castrol gtx. Shift to mobil 1 at 3000 miles or so

DO NOT start it up without driving it for shits and giggles.

The most important is the first 20 miles. Put heavy load on the rings and immediately change the oil to get that piston ring dust outa there. Ive done this several times and all engines are still running like tops.

Make sure youre coating friction surfaces like the insides of bearings and cams with assembly lube, and installing pistons with a thin coat of oil on the cylinder walls

As far as your turbo, use pedal control to keep the boost under 10-14psi and youll be alright

[Kingtal0n]

For the first 20 miles, let it get to operating temp before driving for sure, heavy throttle and rev match downshift engine braking, sorta like racing around. You want boost and vaccuum, both create ring seal. Dont hold the RPMs at the same place for the first 500 miles, work it around the revband. Oil changes at 20 miles, 250 miles, 750 miles, and 1500 miles starting with castrol gtx. Shift to mobil 1 at 3000 miles or so

DO NOT start it up without driving it for shits and giggles.

The most important is the first 20 miles. Put heavy load on the rings and immediately change the oil to get that piston ring dust outa there. Ive done this several times and all engines are still running like tops.

Make sure youre coating friction surfaces like the insides of bearings and cams with assembly lube, and installing pistons with a thin coat of oil on the cylinder walls

As far as your turbo, use pedal control to keep the boost under 10-14psi and youll be alright

Kingtal0n likes this ^^

Except this part,
For first start up, unplug the cas to prevent spark and fuel, then crank the engine 10-15 times to ensure oil has made its way around the engine, plug cas back in and crank until the car starts (might not happen immediately).

We have the technology to avoid "dry cranking", a video is worth a thousand pictures,
http://i9.photobucket.com/albums/a90/kingtal0n/Terry_240sx/th_preoil_zpsdlaxkp1n.mp4 (http://i9.photobucket.com/albums/a90/kingtal0n/Terry_240sx/preoil_zpsdlaxkp1n.mp4)