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. :nod:

[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? :confused:

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 :thumb:

[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? :confused:

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.

[RoadWarrior222]

So, you updated to modern practices no doubt, used different alloys, thinner ring package, used a machine shop that guaranteed tolerances to a few millionths and moly sprayed the bores? I doubt it.

[contraption22]

So, you updated to modern practices no doubt, used different alloys, thinner ring package, used a machine shop that guaranteed tolerances to a few millionths and moly sprayed the bores? I doubt it.

Yup. I did that all. I don't even really need to use oil anymore. I just spray some WD40 down the spark plug holes every 3000 miles.

40209

[RoadWarrior222]

Well in the last 10 years engine technology has changed a lot, believe it or not, sand cast or foam cast blocks have metal in that the engineers didn't really want in there, because all it does is warp the fugger funny when it gets hot, that's what oldskool tolerances have to allow for. Current practice is to use high pressure die castings and cast liners, there is less of the metal the engineers didn't want, so tolerances can be a lot tighter, and break in is minimal to non-existant... take 3 Hyundais off the lot, do nothing to one, have the other two rebuilt at your average rebuild shop and run them in differenty, but they'll end up down on power, emissions, mpg, vs the one that was unmolested, because rebuilders are 10 years behind the curve still, and always have been (Never buy a car younger than 5 years with a rebuilt motor, it's messed up, guaranteed...) but the one that's run in according to the type of hone and rings used in it, will probably do better than the other..... if other critical factory coatings haven't been disturbed and they run at all.

[paduster]

my motor is new rings and bearings but used pistions

[Pat]

Let's be realistic before casting stones...race motors are generally not able to be broken in the 200 mile method. The motors I've built have been primarily in race cars. Best I can do is buzz it around the block in my small neighborhood (and I mean small neighborhood. No WOT, no long pulls, just a 20 mph drive around the block), make sure nothing leaks and then it's go time.

I can honestly say I haven't had much in the way of ring seal issues and I doubt I'm leaving that much power on the table. My engines have generally pulled my cars down the 1/4 pretty well for what they are. I find it hard to believe that I'm missing 10 hp I should have from ring seal/friction.

My take is that break in procedure is not nearly as important as what many make it out to be. If you need to run a car for hundreds of miles following specific instructions to make your rings seat, you likely did something wrong in the build.

[Sundance 6g72]

why is everyone ignoring the link brent and i posted?

[RoadWarrior222]

I are not, but couple of points, a new bike, snowmobile, it has been run to check for leaks etc at the factory, that's used up your "free" 5 minute test.... cars are usually into 2nd stage by the time you get them new, too late to do anything. too much running by delivery people and may not have needed it with different motor construction/tolerance... anthing that's rebuilt different story, you get your brief chance to check it out, then the clock is ticking, you have to get on it.... likely you will ease into it at first, then go harder as you gain confidence and end up with a profile very like what they're saying there.

[Sundance 6g72]

i figured if its going to break, it mine as well break right away so i just let it get up to a decent temp and went WOT as hard as i could and let it do some engine decel

[Ondonti]

I suggest not following any advice rooted in "works for me but I can't give any legitimate references." Read a book, they all say the same thing. Nobody would put this heat cycle advice past a publisher. Giving BAD advice for something so critical and expensive is a big no no.

Pat is breaking in his motor racing it. I didn't see anyone suggesting a 200 mile silly nanny breakin so why are we even talking about that.


Warmup and idle heat cycling is for Slider cam motors to break in the camshafts. That has nothing to do with seating a piston ring. Piston rings are seated, not "broken in."
Seating means knocking down the highspots on the cylinder hone crosshatch. That is why a heat cycle does not help and why you must create huge cylinder pressures to have a good breakin.

Anymore talk about "breakin" without accepting the fact of what ring seating consists of is bad advice. Research before advising. My advice, look someplace else, anyplace else. #1 hit on google for engine breakin is the link that Joe and I posted FOR A REASON.

High precision rebuilds try to minimize the amount of seating required by doing a 2nd superfine hone after the rough hone because people want an instant seat or the owner can't be trusted to do things right. The piston rings still need to seat.
------------


What grit is the hone going to be? Hone grit must match the ring choice. I went with 220 and beat the crap out of the chrome rings.
I have a feeling nothing about honing before replacing the rings has even been mentioned by Ben.

---------- Post added at 02:50 AM ---------- Previous post was at 02:41 AM ----------


Let's be realistic before casting stones...race motors are generally not able to be broken in the 200 mile method. The motors I've built have been primarily in race cars. Best I can do is buzz it around the block in my small neighborhood (and I mean small neighborhood. No WOT, no long pulls, just a 20 mph drive around the block), make sure nothing leaks and then it's go time.

I can honestly say I haven't had much in the way of ring seal issues and I doubt I'm leaving that much power on the table. My engines have generally pulled my cars down the 1/4 pretty well for what they are. I find it hard to believe that I'm missing 10 hp I should have from ring seal/friction.

My take is that break in procedure is not nearly as important as what many make it out to be. If you need to run a car for hundreds of miles following specific instructions to make your rings seat, you likely did something wrong in the build.


Who exactly are you pointing out as wrong? Nobody suggested a long breakin drive. All I see is proper breakin advice, which is to create high combustion pressure, and the terrible heat cycle glaze technique. You would never notice 10 hp. 10 hp can be a few tenths of a degree of timing at the power levels you are making. I never felt spark blowout until it became very bad but the dyno can see 20+hp jumps easy.

Me, I would do anything I could to improve BSFC when its FREE. Your lack of a method ends up seating the rings because you have no patience (you shouldn't) and want to go racing.
Even though you are fine I would still read the link. Its almost word for word what every engine building book I have read is. I could care less about Hastings or picking a fight with Simon even when he is correct. I miss the days when Frank would correct things instead of let you guys post T.D. style advice. I never accept advice as being good just because the person owns a fast car. If that was the case then a whole lotta smart people here would need to delete their accounts.

Take 2 engines on an engine dyno. Break one in with hard pulls and decel, let the other silly nanny around, and the properly seated rings will show a HP advantage. The evidence I see here is "I think what I did works well so I am correct." Invalid as there is no comparison, no physics, no logic. Pat is breaking in his motor without meaning to and then arguying that its unnecessary. Try idling a fresh motor for 4 hours and see how well that goes. Even Mike probably ends up seating his rings decently because I seriously doubt he has the patience to lay off the gas pedal.

So both people who say its not important still do it.

[contraption22]

I think we agree more than disagree. I explained my first startup procedure with the two heat cycles. After that the engine is ready for normal use/abuse. My whole point was that some believe in these long break in procedures before an engine can be worked hard, and they seem rediculous to me. As you noted, nobody here seemed to offer a counterpoint, but argued about it anyway.

[Pat]

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.


I suggest not following any advice rooted in "works for me but I can't give any legitimate references." Read a book, they all say the same thing. Nobody would put this heat cycle advice past a publisher. Giving BAD advice for something so critical and expensive is a big no no.

Pat is breaking in his motor racing it. I didn't see anyone suggesting a 200 mile silly nanny breakin so why are we even talking about that.


Warmup and idle heat cycling is for Slider cam motors to break in the camshafts. That has nothing to do with seating a piston ring. Piston rings are seated, not "broken in."
Seating means knocking down the highspots on the cylinder hone crosshatch. That is why a heat cycle does not help and why you must create huge cylinder pressures to have a good breakin.

Anymore talk about "breakin" without accepting the fact of what ring seating consists of is bad advice. Research before advising. My advice, look someplace else, anyplace else. #1 hit on google for engine breakin is the link that Joe and I posted FOR A REASON.

High precision rebuilds try to minimize the amount of seating required by doing a 2nd superfine hone after the rough hone because people want an instant seat or the owner can't be trusted to do things right. The piston rings still need to seat.
------------


What grit is the hone going to be? Hone grit must match the ring choice. I went with 220 and beat the crap out of the chrome rings.
I have a feeling nothing about honing before replacing the rings has even been mentioned by Ben.

---------- Post added at 02:50 AM ---------- Previous post was at 02:41 AM ----------




Who exactly are you pointing out as wrong? Nobody suggested a long breakin drive. All I see is proper breakin advice, which is to create high combustion pressure, and the terrible heat cycle glaze technique. You would never notice 10 hp. 10 hp can be a few tenths of a degree of timing at the power levels you are making. I never felt spark blowout until it became very bad but the dyno can see 20+hp jumps easy.

Me, I would do anything I could to improve BSFC when its FREE. Your lack of a method ends up seating the rings because you have no patience (you shouldn't) and want to go racing.
Even though you are fine I would still read the link. Its almost word for word what every engine building book I have read is. I could care less about Hastings or picking a fight with Simon even when he is correct. I miss the days when Frank would correct things instead of let you guys post T.D. style advice. I never accept advice as being good just because the person owns a fast car. If that was the case then a whole lotta smart people here would need to delete their accounts.

Take 2 engines on an engine dyno. Break one in with hard pulls and decel, let the other silly nanny around, and the properly seated rings will show a HP advantage. The evidence I see here is "I think what I did works well so I am correct." Invalid as there is no comparison, no physics, no logic. Pat is breaking in his motor without meaning to and then arguying that its unnecessary. Try idling a fresh motor for 4 hours and see how well that goes. Even Mike probably ends up seating his rings decently because I seriously doubt he has the patience to lay off the gas pedal.

So both people who say its not important still do it.

I was referencing the post quoted above by roadwarrior.

[paduster]

I was planning on honeing the cylinders but was going to call and find out the grit I should use

[RoadWarrior222]

Yes, best to get that from ring MFer and also inquire as to pattern, usually for moly faced you're aiming for a 60* diamond type pattern, but other ring types may need a more or less aggressive angle.

[turbovanman²]

I are not, but couple of points, a new bike, snowmobile, it has been run to check for leaks etc at the factory, that's used up your "free" 5 minute test.... cars are usually into 2nd stage by the time you get them new, too late to do anything. too much running by delivery people and may not have needed it with different motor construction/tolerance... anthing that's rebuilt different story, you get your brief chance to check it out, then the clock is ticking, you have to get on it.... likely you will ease into it at first, then go harder as you gain confidence and end up with a profile very like what they're saying there.

I guarantee any of those have been beaten badly by the PDI people. Trust me, when we did PDI's at the dealer, we beat the living snot out of them, not knowing we were doing the customer a favour, lol.

[black86glhs]

You guys are all wrong........and all correct. Brent, you keep thinking that just because it is written down that it is correct. Not saying they are wrong in this case, but you put too much faith in your reasoning.
Bottom line....if it doesn't have low cylinder pressure or a ton of blow-by......your doing just fine.