Best Break-in Procedure

[SkullWorks]

Ummm...no no old geezers relied upon,

Engine builders/ Dyno Operators/ All professionals.

[mrtodd]

Originally Posted by SkullWorks

Ummm...no no old geezers relied upon,

Engine builders/ Dyno Operators/ All professionals.

^This.

All the Honda engines I rebuilt I used dino oil to begin with, then switched over to synthetic after so many miles. My last engine I built, which also happens to be my current engine in my EH2, I actually used basic non-detergent oil for the first 2 changes, then regular castrol dino oil, THEN finally synthetic. I beat the shit out of the engine for the first 50 miles.

My compression on this engine is the highest I've ever had on all my builds. This isn't only my experience, but many other Honda builders have proven the same results. These aren't old engine builder tales. The science is simple - synthetic is literally too slippery for rings to seat properly. Rings need friction to seat, which is the reason why cylinders are honed at a specific grit.

Now, a new car will be different. The manufacturer WILL have done a short factory break-in/bed-in procedure before the engine is even installed in the chassis. This may or may not be enough to have the rings fully seated.

Do what you want, either way it's not going to make or break your FR-S/BRZ. But for those of us that are OCD builders.....we know what we're going to do.

[SkullWorks]

Originally Posted by mrtodd

Do what you want, either way it's not going to make or break your FR-S/BRZ. But for those of us that are OCD builders.....we know what we're going to do.

Exactly, It may be good enough already but that isn't going to keep me from taking steps to make it better.

[zoomzoomers]

Originally Posted by mrtodd

^This.

All the Honda engines I rebuilt I used dino oil to begin with, then switched over to synthetic after so many miles. My last engine I built, which also happens to be my current engine in my EH2, I actually used basic non-detergent oil for the first 2 changes, then regular castrol dino oil, THEN finally synthetic. I beat the shit out of the engine for the first 50 miles.

My compression on this engine is the highest I've ever had on all my builds. This isn't only my experience, but many other Honda builders have proven the same results. These aren't old engine builder tales. The science is simple - synthetic is literally too slippery for rings to seat properly. Rings need friction to seat, which is the reason why cylinders are honed at a specific grit.

Now, a new car will be different. The manufacturer WILL have done a short factory break-in/bed-in procedure before the engine is even installed in the chassis. This may or may not be enough to have the rings fully seated.

Do what you want, either way it's not going to make or break your FR-S/BRZ. But for those of us that are OCD builders.....we know what we're going to do.

I'm not oil expert. I mean all I do is drive it like I stole it. But my previous several Bimmers came with synethetic and didn't even have an oil stick. I know, you should have seen the BMW forums then when BMW of America released that info about the no oil stick. Till this day, I haven't heard many issues with break in or rings not seating properly. Now, blown engines is another issue LOL

On another note and I'm just curious here, but who in the world keeps their cars over 4 to 5 years max these days. So why worry so much? Plus these motors are well engineered these days and I hardly hear of anyone having issues due to improper break in.

[Kieranz]

Originally Posted by maxeveland

Just thought I should revive this thread since now we know through the BRZ manual that the recommended break in is at 1000 miles with a 4k rev limit.

Interesting thread. Not sure if I am going to follow Subie's recommendations this time around..

Currently have a 08 Tribeca with a 3.6 engine @ 45k miles. I've been burning though about 1.5qt of oil/1000 miles. Fortunately i am still under powertrain, so it looks like Subaru is going to give me a new short block. Makes me wonder if "following the manuals recommendations" - i was diligent in varying speed and keeping it under 4k revs caused my issues a few years back. After doing a lot of research for my current situation, it seems like the boxers burn more oil than conventional engine setups. Not sure if the oil consumption issues are just caused by the boxer layout, or these engines just need a hard break-in to get everything seated.

Anyhow I'm now debating on how to break in the new ride when it arrives (along with my new Tribeca engine as well). I guess the consensus here is to drive it like you stole it.

Funny in the BRZ manual it says that the magic oil burn number before Subaru thinks it's a warranty issue is 1.1qts/600 miles. On my Tribeca the number is 1qt/1200 miles. The 2.0 also takes 5.8qts total, a lot of oil for a little guy.

[carbonBLUE]

Originally Posted by ahausheer

FYI: The EPA reports that mpg will increase for the first few thousand miles. Leads me to believe complete ''break in'' takes a while

a street car driven like a street car, i wouldnt hammer it for long periods of time till you had about 5k on the engine at least, but still hit the redline time to time after about 500 miles, its what i did with my last engine, now i hit the fuel cut 1-2 times a day and drive it hard cold, i think there is about 60k on my current engine and ive beaten it for about 50k every day like that

i do compression checks before and after oil changes and i get about the same results depending on humidity and outside temps, no metal filings yet

[tranzformer]

Originally Posted by carbonBLUE

a street car driven like a street car, i wouldnt hammer it for long periods of time till you had about 5k on the engine at least, but still hit the redline time to time after about 500 miles, its what i did with my last engine, now i hit the fuel cut 1-2 times a day and drive it hard cold, i think there is about 60k on my current engine and ive beaten it for about 50k every day like that

i do compression checks before and after oil changes and i get about the same results depending on humidity and outside temps, no metal filings yet

Regardless of how new or old the engine is, isn't that a bad idea not to wait until the engine is up to operating temp? I would never run a cold engine hard, no matter how well broken in it was.

[BRZ]

there's already a thread about breaking into the BRZ?! ha ha, kidding.


this is an interesting thread since the BRZ is gonna be the first new car i've purchased.

[carbonBLUE]

Originally Posted by tranzformer

Regardless of how new or old the engine is, isn't that a bad idea not to wait until the engine is up to operating temp? I would never run a cold engine hard, no matter how well broken in it was.

well i dont run it to the cold engine limiter just to about 4-5k rpms the cold limiter is at 6600 rpms lol...

plus i havnt lost any engine compression in the last 2 years running it like that... nor does my oil burn, my engine doesnt even warm up %100 when its below 70F outside for some reason... but air/fuel ratios are right and im putting 20+ whp over stock, i may just have a really good engine and not know it....

[ahausheer]

You can't break in an engine unless it's outside the car. You break in a CAR, not the engine. The break-in procedure in the manual is not saying this is the break-in for the motor, it's taking everything into account. There are tons of other considerations, particularly, the transmission. There will be metal shavings in the transmission oil that need to be filtered, perhaps speed and load needs to be low at first to break in the gears and prevent metal shavings from becoming detrimental. I also wonder if the gears need to hone or bed each other. All im saying is follow the stupid manual, perhaps it is a compromise on certain engine components but it must be better overall.

[carbonBLUE]

Originally Posted by ahausheer

You can't break in an engine unless it's outside the car. You break in a CAR, not the engine. The break-in procedure in the manual is not saying this is the break-in for the motor, it's taking everything into account. There are tons of other considerations, particularly, the transmission. There will be metal shavings in the transmission oil that need to be filtered, perhaps speed and load needs to be low at first to break in the gears and prevent metal shavings from becoming detrimental. I also wonder if the gears need to hone or bed each other. All im saying is follow the stupid manual, perhaps it is a compromise on certain engine components but it must be better overall.

yeah thats all i firmly believe, cars come with 2-3 miles on them from being dyno tested and partially broken in at the factory to make sure everything runs, new engines need to be abused here and there for 1-2 gears every 50-60 miles after the first 500-1000 miles to break them in right...keeping the engine below 4000 rpms doesnt let the engine stretch its legs enough

[ahausheer]

Originally Posted by carbonBLUE

yeah thats all i firmly believe, cars come with 2-3 miles on them from being dyno tested and partially broken in at the factory to make sure everything runs, new engines need to be abused here and there for 1-2 gears every 50-60 miles after the first 500-1000 miles to break them in right...keeping the engine below 4000 rpms doesnt let the engine stretch its legs enough

Can you offer an explanation why the manual states what it does? If you are correct than you must know why the manual is wrong. Otherwise you are just guessing. Keep in mind I'm talking about breaking in a car as a whole.

[carbonBLUE]

Originally Posted by ahausheer

Can you offer an explanation why the manual states what it does? If you are correct than you must know why the manual is wrong. Otherwise you are just guessing. Keep in mind I'm talking about breaking in a car as a whole.

not saying the manual is wrong, in fact it probably is the safest way of breaking in an engine if you go by the manual
its the way ive broken in 2 engines, and 3 of my friends have followed those guidelines as well and have very reliable engines, if i do break the engine or it doesnt last more than 50k miles ill buy a new one and break it in like the manual says...

when i break in an engine i drain and check oil for metal shavings every 100-200 miles and refill with the same oil till 4k miles, i do this mainly to filter out as many shavings that do come out during break in that isnt caught by the oil filter

i want the rings to seal better and to keep compression as high as possible, i broke my current engine in like that, and its got 50k miles and i havnt lost compression or had any other problems, can you explain why my method is bad if it works?

maybe it wont work with all engines and thats what im trying to figure out, if it is a good/bad idea for this engine to be broken in hard and i will gladly fork over 6k for a new engine if my warranty doesnt cover it...

[ahausheer]

Originally Posted by carbonBLUE

not saying the manual is wrong, in fact it probably is the safest way of breaking in an engine if you go by the manual
its the way ive broken in 2 engines, and 3 of my friends have followed those guidelines as well and have very reliable engines, if i do break the engine or it doesnt last more than 50k miles ill buy a new one and break it in like the manual says...

when i break in an engine i drain and check oil for metal shavings every 100-200 miles and refill with the same oil till 4k miles, i do this mainly to filter out as many shavings that do come out during break in that isnt caught by the oil filter

i want the rings to seal better and to keep compression as high as possible, i broke my current engine in like that, and its got 50k miles and i havnt lost compression or had any other problems, can you explain why my method is bad if it works?

maybe it wont work with all engines and thats what im trying to figure out, if it is a good/bad idea for this engine to be broken in hard and i will gladly fork over 6k for a new engine if my warranty doesnt cover it...

Based on all the anecdotal data there may be something to the break it in hard idea. However, until I see scientific data ill remain a skeptic and will follow the procedure that is recommended by companies that have built their entire reputation on reliability.