Breaking in a motor, Be nice or give it WOT.

[Adydas]

Well, i put it to you toyspeed after doing some reasearch ive some what changed my mind on the " how to brake in a motor thing. ".

Seems that being nice isnt the right way " Now a days " due to many things such as honing of the bore and the technology used ( from when it was done 16 years ago by factory. )

So do you Agree or dissagree with what im about to write, and why.

On a Dyno:
Warm the engine up
completely !!

Then, using 4th gear:

Do Three 1/2 Throttle dyno runs from
40% - 60% of your engine's max rpm
Let it Cool Down For About 15 Minutes

Do Three 3/4 Throttle dyno runs from
40% - 80% of your engine's max rpm
Let it Cool Down For About 15 Minutes

Do Three Full Throttle dyno runs from
30% - 100% of your engine's max rpm
Let it Cool Down For About 15 Minutes
Go For It !!



Yeah - But ...
the owner's manual says to break it in easy ...

Notice that this technique isn't "beating" on the engine, but rather taking a purposeful, methodical approach to sealing the rings. The logic to this method is sound. However, some will have a hard time with this approach, since it seems to "go against the grain".

The argument for an easy break-in is usually: "that's what the manual says" ....

Or more specifically: "there are tight parts in the engine and you might do damage or even seize it if you run it hard."

Consider this:
Due to the vastly improved metal casting and machining technologies which are now used, tight parts in new engines are not normal. A manufacturing mistake causing a tight clearance is an extremely rare occurrence these days. But, if there is something wrong with the engine clearances from the factory, no amount of gentle running will fix the problem.

The real reason ???
So why do all the owner's manuals say to take it easy for the first
thousand miles ???

This is a good question

Q: What is the most common cause of engine problems ???
A: Failure to:
Warm the engine up completely before running it hard !!!

Q: What is the second most common cause of engine problems ???
A: An easy break in !!!

Because, when the rings don't seal well, the blow-by gasses contaminate the oil with acids and other harmful combustion by-products !!

Ironically, an "easy break in" is not at all what it seems. By trying to "protect" the engine, the exact opposite happens, as leaky rings continue to contaminate your engine oil for the rest of the life of your engine !!


During "zing-zing-zing" the rings don't get loaded for more than a split second, whereas during "bwaaaaaAAAAAA", the engine is in 100% ring sealing mode.

[Leon]

The only rebuilt engine I've ever dealt with was in my old mini.

Drove it gently to Manfeild from Wellington. Drove it 3/4 death on Saturday, 112.5% death on Sunday. Nothing jumped out the side.

Not an entirely scientific test I realise

[Silent Knight]

Cliff breaking a new engine in on a Dyno FTW.

Allot of manufacturers break their cars in on a Dyno before they go roll out on to the floor for sale. Some whilst in the car and some of them just gets engine dyno'd to get broken in.

[CAMB01]

Ive built a few engines in my time and have had success with going through about 85% of the revs in every gear, and driving up a hill in the mid range revs. Never had a problem with any of the engines ive built.

[Adydas]

so ud say its all good and I shouldn't worry ??

[CAMB01]

just drive it normally

[Caveman]

I think you should put some references to credit the person that wrote that and avoid claims of plagiarism.

[RomanV]

^Agree with above ^

So do you Agree or dissagree with what im about to copy and paste and why.

Fixed.

EDIT: *cough*