Engine Break in Discussion

[APEXi240]

Definately do not break it in slow. Take it out for the first 30 miles and floor it up hills every chance you get.. Then change the oil at 30 miles. Then drive it normally until 330 miles and change the oild again. After that it will be broken in and will love you for it.

Anyone who breaks in their car slowley will end up with a slow inefficient car. Break em in fast and they will be fast. You need to seat those rings within the first 30 miles and to do that you need to put lots of pressure on them while they wear. If they wear at idle or while the car is being babied, they will not seat as well and you will not get as much final power.

Are you a complete moron? Did the driver of the "special" bus teach you about breaking in cars?

Floor it up hills, great idea, everyone likes their clutch to slip and set poorly after the first 100 miles.

If you break it in slow it will be slow? Could this be any more wrong? I know my car was broken in properly and it still rips from 1500 to redline just like it should. How will you not get enough final power? Does it change...like "Your G35 is 280 at the fly, but if you break it in slow you'll end up with 250 at the fly, good luck with it"

Even if you were kidding about all this you are a fool.

Impele, congrats on the car, I'd kill for one of them....BE VERY CAREFUL TO NO CRASH IT, a good majority of kids get into accidents early on. Anyway, as far as breaking it in, Fred got everything about right, also to add, I'd change the oil at 500, then 1500, then follow normal changes. Baby that car constantly, I know I would. Good luck with it.

[stuofsci02]

Maybe before you post you should do a little research of your own. If you want to break in your car easy then by all means go ahead. Do be a retard and try to start something by calling people a fool. Ultimately you can do what you want with your car, but he was asking for peoples opinions and this was mine.

You might consider doing a little reading.

I will give you a hand with where to start:

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

[PalmerWMD]

Interesting read Stu.Still why doesnt the factory recommend the same?And why are there so many stories out there of PPL not doing break-in gently and winding up with hi oil consumption?

Fred....

[stuofsci02]

Some other articles you might be interested in.

http://www.howstuffworks.com/nascar4.ht ... cedure.htm

[stuofsci02]

I believe the factory recommends the slow break in for safety reasons. It would be crazy and a possible liability for them to say take your car out and punch it from 20-60MPH ten times. Someone could crash or something. Also, it is really not good to go out and drive at redline for more than say 10 sec in the 1000 kms. The cylinders are nto ready for that amount of high heat transfer quite yet. Some one might confuse "punch the throttle" to mean autocross at 7000 RPM for an hour : )

[stuofsci02]

I think it is important not to let the RPMs go too high, but at the same time babying will have a negative effect too.

[BlockHead]

idk everyone I have heard talking about engine break-ins say take it slow to allow everything to seat correctly. Like a friends Rx-7(yeah its different) but they didnt break the new race motor in before tuning it and they blew it on the dyno. But I can see what you are saying to. I have also heard if somehting is going to go wrong its going to happen regardless of how you drive it.

[YamaOni]

I looked into the info you posted and it all seems to apply to high horsepower short life engines, how does that info apply to the daily driver weekend killer? I am rebuilding an RB20 and want to know both sides of the story.

[Q45tech]

Each engine is different in design and materials!Without analysing [each of 3] ring material and bearing material you are quessing! Without knowing all clearances accurately to 0.0001" you are guessing. Without knowing the coefficients of expansion of each material at each surface you are guessing!

The cardinal rule is what ever you do, don't exceed 3,000 rpm on any engine until all the temps are warmed to 170-180F EVER brand new or very used. Always monitor oil temperature and real pressure accurately [1 psi increments electronically].

[Chally]

May I just add, when breaking in the engine, you accelerate from 30-60mph 10 times, in top gear (not overdrive) where possible. If you have ever done it, you will feel the difference by the end.

That said, as Q45Tech pointed out, every engine is different! The latest engines don't need the same break in rituals, because the way they make the pistons now, (they don't expand as much)the way they hone the cylinders, (diamond hone which cuts instdead of peeling the metal) & the rings designed specially, so that the engine will be bedded in by the time the engine is at full temperature. (courtesy of Federal Mogul Tech. Division, when it was in Australia)

This is the reason most remans don't come anywhere near the original builds. They don't have the capital to set up for the same precision the big boys do.

eg. When Nissan builds an engine, the bores are honed & measured, & are fitted with one of 4 different sized pistons. This is also done on the Crank. 3-4 different sized slippers for a standard size crank. VERY PRECISE!

[Q45tech]

The reason cast piston are used is the alloy can be tailored better as to coefficient of expansion [the amount of silicon in alloy]. With precise expansion vs temperature, the clearances can be narrower [less cold piston skirt slap] quieter engine when new and thru the 100k design life [the time when you might get warranty].With precise control softer rings [for less hone wear] can be used which when coupled with a rigid cylinder.

Bearings are the key and most abused item, as the crank is forged and super strong.............Cold starts with cold oil are the major cause of wear, even with Synthetic oil which still doesn't lubricate as designed until 160F [even though it flows better because the molecules are more consistant in size -less friction].....its cold lubricity may be only 50% vs conventionals 25%!

How you do each warm up is critical----the least load possible till the oil warms up.

The reason Mobil 1 and BMW were able to go 1,000,000 miles with little wear is the car ran 24 hours per day and even the change oil was preheated to operating temperature so a cold start wouldn't occur and changed every 2 days at 3,750 miles.

Getting 300,000 miles out of a daily driver with 2-3-4 cold Southern starts per day is one thing but don't expect the same in Minnesota.

[Chally]

Yes, they even got 1,000,000 miles out of a VW beetle, but it was used as a Taxi 24/7 & the engine never got cold.

[Q45tech]

5,000 cold [what ever ambient is] starts is probably equal to a million miles.

[miteymax86]

I've got a small comment here, since my stepdad just started leasing his brand-new truck(0miles on the odo when he picks it up from the dealer!) the factory literature stated that for the break-in period you should drive the engine over the widest range of rpms possible taking care not to overheat it or some other crap, I'll try to track down the actual form, b/c I know he's got it around somewhere

[Nismo_Freak]

This is an interesting thread. Just thought I would say that.

[Q45tech]

It really boils down to all aluminum, partial aluminum, or all cast iron engines and 2 valves or 4 valves [ or 3 {MB} or 5 {Audi}] per cylinder.

Early proceedures to make things last 300,000 miles are quite different and you want the least wear per 3,000 mile oil change you can get..............you want the mid life crisis to begin at 150,000 miles not 30,000 miles as is typical with old style US engines.

[Movingviolation240]

Lycoming suggest breaking in their aircraft motors at full throttle. The procedure is to run mineral oil in it for the first 100hrs and to run it rich and on the redline the whole time.

Rawl from Miller performance suggested to me that I run the motor hard as well "two full throttle runs at LOW boost, then let it cool down. After that it's broke in" and a I will say my motor NEVER smoked after I did that. While a few of my other freinds who took the 'baby it for 1000 miles' approach were STILL getting smoke at 2000 miles.

that's just my experience, but reading those articles seems to prove that it's a valid point.

PaulOrlando, FL

[Chally]

Thats right, but the aircraft motor isn't under load & their full throttle (red line) is designed to be where the motor can run all day.

Running rich also keeps the engine cooler.

We use 10 full throttle runs, but only from about 30-70mph in 4th gear, so you did OK.

[Mayhem_J30]

eg. When Nissan builds an engine, the bores are honed & measured, & are fitted with one of 4 different sized pistons. This is also done on the Crank. 3-4 different sized slippers for a standard size crank. VERY PRECISE!

Chally,I'd like to know more about this. Is this saying Nissan expects the bores to not be consistent with size?

[Chally]

That's right. Even though the bores etc. are done by an automated machine, after honeing there, can be minute differences, so Nissan categorised the piston differences & the bore differences & matched them to the point where the clearances are as close as possible to each other, which gives better engine life.

That way, you don't get a "Tight" bore to piston or a "Loose" bore to piston situation.The same goes with the crank.

[bpmguys]

what it comes down to is I don't think anybody knows. We have an engine builder on site that says break it in slow. That engine produced more hp than an engine that was run hard at first. The problem was that the engine that was broken in hard at first had better leakdown numbers. hmmm