Engine Break-In:

[racerx]

After all is assembled and running, I understand that it's a good idea to drive gingerly for about 1000 miles. I've got all stock engine management sensors and stuff working so I'm not concerned with A/F ratio and stuff like that...

What I'm wondering is: Does it take a while for the rings to start making good compression? Do they need to seat properly first in order to hold the compression they're designed to hold?

Is the same true for the valve train? (just got the head completely redone at a machine shop)

[white ricer]

yeah you break the engine in so the rings and valves will seal correctly, use non detergent straight weight oil for it, from what ive seen it helps seal a little better. Your compression may read a little low but thats the rings like you said.

[88Accord-DX]

Yeah, your supposed to drive it easy for the first 1,000 miles. Don't rev your RPM's over 4,000. Not supposed to "lug" the engine. Don't drive over 55-60 m.p.h.
As long as you "deglazed" or bored the cylinder walls out & have a good 50-60 degree crosshatch pattern, it takes a little time (500 miles or so) for the rings to seat properly.
Another engine break in precedure is to run the car up to 50 mph. & let off the gas untill 20 mph. Do that for 5-6 times for initial run. Re-adjust your valve lash at around 500-1,000 miles, change the oil at 200 miles & again at 1,000 miles.

[bobafett]

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

this is a really interesting article as well. im planning on trying something like this..

[88Accord-DX]

He has got some interesting points. Some say run it hard, others don't. Just a matter of what kind of risk you want to take I guess.

[racerx]

interesting stuff...

I'm using straight SAE 30 oil right now. magnets on the oil filter, gonna change oil at 100-ish, then at 500, then at 1000. I think that's gonna be ok.

What oil should I use at each oil change? Should I stick with SAE 30 until 1000 miles?

I broke the glaze and got the hatch work going, so I should be good to go for that.


It seems that as I drive this, the engine is getting a little bit peppier with each passing mile. I like it. ;)

[racerx]

*bump* oil recommendations?

[bobafett]

a lot of shops have told me to use cheap oil for your break in ,because you are changing it so often its not worth it to use awesome stuff like synthetics. :)

makes me nervous to use 'cheap' oil, but i will probably just use castrol gtx 30w :) after that its nothing but royal purple :D

[racerx]

Royal Waste of Money.

anyway, should I be using SAE 30 the whole 1000 miles? or just the first 100? or 500? ...

[88Accord-DX]

I just re-built an engine.... I run Castrol 10w30. So, SEA oil to me is fine. I don't think sythetic oil is good for break in though.

[bobafett]

yeah its not great during break in, also u will go thru $200 of synthetic in a hurry!

[Accordtheory]

The oil is not very important. I don't think I would run synthetic though, until after the first 1500 miles or so. I would change the oil pretty quickly after I first started driving, but then after the initial change, I would leave that oil in until maybe 1500 miles, depending on what it looked like. And driving the car hard will seat the rings faster, but I wouldn't drive it really hard until you have 1000 miles on it, at least, unless the rest of the engine, bottom end bearings in particular, was already broken in. Then you could just drive it hard and seat the rings quickly.

Do you ever wonder how they build engines in a magazine or whatever and then do a dyno test almost immediately after building them? Cylinder pressure is what seats rings..

[racerx]

alright. i think i'm gonna stick with SAE 30 oil for the entire 1000miles. Maybe I'll change it to 10W-30 by the end, and then finally 5W-30.

I'm using Lucas Synthetic Oil Stabilizer too, for all the oil changes. That should definately help keep things lubed up. ;)

We'll see about the whole hard break in. I'd bet that's more for built engines and hard rings, etc. You know, engines that are built for hundreds of HP over stock. If you put everything back together like it came from the factory, you probably want to go with factory instructions.

If hard break-in's were good for stock (or almost stock) engines, the factory manual would say: Drive it like a bat out of hell for the first 20 miles at least.

Why don't they say that? Because they have to warranty the parts in the car. Why would a company that's liable for damage to the engine give bad instructions on engine break-in? Makes no sense.

Truth is, if you're engine is not 100% built, do a soft break-in and do it right.

[AccordEpicenter]

id use 10w-30 dino oil (or 10w-40) let it start and run until you hear the fans come on and its up to temp. Once you get it up to temp and everything runs/looks good, go out on the highway and do some 3rd gear pulls, like 3krpm-5500rpm and then engine brake back down and do it again. The load on the engine and acceleration help break in the rings, then the engine breaking polishes them and the cylinders. I wouldnt go out and rape it right away but i wouldnt baby it like the manual says, just go out and do some pulls

[bobafett]

yeah thats what im planning on doing. another strategy i have heard is to lug the motor, like try going up a hill in 5th at 35mph. the pressure that is created in the cylinder will help the rings seal which is what you are after. :)

[Vanilla Sky]

first, NEVER run synthetic, OR any stabilizers during break in. nothing but straight dino oil.

and reguarding the hard breaking vs soft, i'd go hard. i've never seen a case in which a soft break-in helped, or a hard break-in hurt. if i'm not mistaken, now all car engines are already ran-in at the factory, at full throttle under load, i believe.

[racerx]

I'll research it a little more. I'm not satisfied with some random redneck/nerds web page with 1 person's opinion. But that's just me.
Besides, the guy thinks that there's "thousands" of PSI in an engine... uh-huh...

but anyway, thanks a ton for all the info and opinions. i guess i won't use any stabilizers next oil change. (should be today)

[Vanilla Sky]

if you think about it, though, his method sounds logical. i know of several high-performance shops that break in engines on the dyno at full throttle as well. you just have tp have an engine built to very good tolerances in order for it to work properly.

BTW, when my dad breaks in a new lawn mower, we run the thing at full-throttle for at the least of half an hour after warming it up. after that, i'll manually blip the throttle a few times, then we run the mower like normal, which would be as high of a load as it will ever see. we have one kohler engine with around 1000 hours on it that hasn't had any repairs needed, and only regular maintenance. our engines typically run much longer than the rest of the machine. that's compared to the many blown engines i've seen that were broken in using the normal manufacturer specified idle break-in.

i'm not saying that the same holds true for a car engine, but that's how we break in a lawn mower.

when we break in a small engine, like a weed eater or blower, we run at full throttle for a whole fuel tank, which is about an hour. so far, not one engine failure. everything else fails, but the engines are still strong.

[bobafett]

yeah on top of all the accounts that hard break ins work fine, its also rumored (i wont claim its true or not) that hard break ins create better seals which keep slightly more power. also its more fun to do a hard break in than try and baby the motor for several months (good thing i drive 500 miles a week lol)

[cardoc33]

The hard break-in thing is an old racers trick. I never thought about the tech behind it, but it works.
As for oil, change it after the first warm up to get all the junk out of the engine. Any lint or dirt that you can't see goes straight into the filter. I have always used whatever weight dino oil you would be normally using. Change it again at 500mi., than again at 1000mi., switching to your fav synth.
Your oil is the blood of the engine, keep it clean.

[Accordtheory]

The hard break in ONLY WORKS FOR THE RINGS. Who cares whatever anyone says, unless it makes sense! If you really understand what happens in an engine as it is being broken in, does a hard break in make sense for main and rod bearings? Not really, what is the point in risking damage? In a previous post I explained how rings break in, and what actually happens to them and the cylinder walls as they go from being fresh to broken in. The bearings are similar, except that if you have any type of high spot, the forces that should be evenly distributed on the bearing surface will be concentrated on that 1 spot, causing it to get extremely hot if you're beating on the engine..that heat can cause localized damage..(material disintegration) and then potentially a spun bearing, and then possibly total engine destruction. (if I remember correctly, the bearings I used in my b series, king alecular bearings, are rated for like 1400 degrees. When I saw that rating, I was like wtf?? but it doesn't mean the whole bearing will ever get that hot..well maybe if you're doing a dyno pull with no oil! That just means that part of the bearing won't melt until it gets that hot.) You can break in rings hard, even some with wd-40 (endyn) but when it comes to bearings, especially rod bearings, I think it is better to take it easy and wear down any imperfections than risk throwing a rod.

p.s. Don't try to break in rings with any type of moly lube..in other words don't get assembly lube on the rings..more friction is the goal there, not less.