Motor break in questions

[sicksubie]

I would like to hear some opinions, suggestions, etc on what the correct way would be to break in a motor. Tom will be assembling my motor at some point this summer and I have bought Duckie's stage III s/c kit. I will be very tempted to assemble everything and just go s/c and all, but I want this to be done properly.

[Trevor]

Originally Posted by sicksubie

I would like to hear some opinions, suggestions, etc on what the correct way would be to break in a motor. Tom will be assembling my motor at some point this summer and I have bought Duckie's stage III s/c kit. I will be very tempted to assemble everything and just go s/c and all, but I want this to be done properly.

My first reaction is to suggest you take Toms advice.

However as a second opinion, I would suggest that you simply treat the engine kindly for the first few miles. (Was nearly going to correct with kms and it is nice to not have to jog old memories. )

The old idea was to not exceed a certain RPM, but the more sensible approach is to not put too heavy a load on the engine. With an automatic, all you have to do is keep the loud pedal away from the floor for a while.

[sicksubie]

Originally Posted by Trevor

My first reaction is to suggest you take Toms advice.

However as a second opinion, I would suggest that you simply treat the engine kindly for the first few miles. (Was nearly going to correct with kms and it is nice to not have to jog old memories. )

The old idea was to not exceed a certain RPM, but the more sensible approach is to not put too heavy a load on the engine. With an automatic, all you have to do is keep the loud pedal away from the floor for a while.

So do you think that putting the blower on immediately is a bad idea?

[Bobb]

Hi Sicksubie, We old guys remember the "Drive slowly for the first one thousand miles" NO high RPM's , no constant RPM's. this breaks down to commin sense. Allow the parts to become freinds with each other. Then change the oil, and your good to go. Take care, BOBB

P/S Liston to tom!

[TomsSVX]

Standard Break-in proceedure

-DON'T romp on it... keep load off the parts for the most part of 1k miles
-Don't findyourself cruising on the highway for extended periods of time without changing rpm(groove the cylinder walls)
-Use regular oil for the 1st 1k and then switch to synthetic afterwards
-Put the blower and everything on but remember to resist the heavy foot

That should be about it... Although engine break-ins are a urban legend by now, I still live and breath by them

Tom

[drivemusicnow]

I guess I'll be the one to disagree.

There is NO reason on a modern engine that was built to spec to "go easy" for a while.

EVERY motor built in a factory of any quality is flogged on a dyno, or in the car on a track before it is ever delivered. Why you ask?

Think of it this way. If something was done wrong (For example to tight of clearances, or too loose torque on bolts etc) it won't fix itself and will eventually fail, even if you spend the first 1000 miles driving like a blind grandmother.

My recomendation, and that of many other people who build numerous modern engines, is to:
Vary RPMs constantly
Do some "not quite full" throttle pulls, and then while holding it in that same gear, let the engine act as a brake

Change the oil after the initial break in. This includes letting the car idle until warm, lots of various RPM and loads, and less than 50 miles.

If something was done wrong, it will fail. If everything was built right, it'll have higher compression, and last longer than the same motor that was broken in "soft".

Many of the rules behind engine break in come from old engines with much looser machining tolerances than are available today.

Google the "mototune" break in method. The same idea is used by factories all over the world, as well as EVERY race engine builder in the world.

Some people will say, "oh well that's fine, but a race engine isn't trying to last 100k miles" which is true, but you have to think that they're also looking for every last hp, and an efficient motor (read high output) is a low wear engine, assuming that the motor in general was designed correctly.

Even so, most people are stuck on the "take it easy" break in method for the mere reason that they just spent a significant amount of money and in their minds they think being "nice" to it during break in will make it last longer.

[Mr. Pockets]

When I rebuilt my MR2's engine, I followed the 'hard break in' procedure. That doesn't mean I beat on it - I just ran it higher than the 'gentle break in' procedure would prescribe. I believe I followed a process I found on the internets. Way to go.

After a week of break-in and several oil changes, I ran it at an autocross, in first gear and against the rev limiter.

The car's been fine. It's been running now for two years (and all of 8k miles) without any trouble. The last time I checked compression it was all within spec.

This is, of course, anecdotal. I'm not advocating either gentle or hard break in - I'm just relaying my experience.

[Tim]

Originally Posted by Trevor

My first reaction is to suggest you take Toms advice.

+1

I didn't listen to him in the beginning and thought I could save money not going with the Koni's instead of the new old stock struts, and here I am replacing them with Koni's when I should have done it in the first place.

[n00b on demand]

Step one: Drive it like you stole it

[Tim]

Step one... cut a hole in the box...

Oops... wrong topic...

[Trevor]

Originally Posted by drivemusicnow

I guess I'll be the one to disagree.

EVERY motor built in a factory of any quality is flogged on a dyno, or in the car on a track before it is ever delivered. Why you ask?

This absolute statement tends to make one wary of the remaining information.

It would be impossible on the basis of cost, to carry out this procedure on any car produced in quantity. This leaves the question, as to whether all cars produced in commercial quantity, constitute the output of factories of low quality.

[TomsSVX]

sorry, I am gonna take the slow road on my break in... Im not gonna flog my $3500 engine without what I consider a proper break in

Tom

[Trevor]

Originally Posted by drivemusicnow

Google the "mototune" break in method. The same idea is used by factories all over the world,

as well as EVERY race engine builder in the world.

.

This statement has just been proven incorrect. Tom is no fool.

What is more full race engines are built with increased tolerances, one of the important reasons being, the lack of opportunity to run them in.

[Crazy_pilot]

Originally Posted by TomsSVX

sorry, I am gonna take the slow road on my break in... Im not gonna flog my $3500 engine without what I consider a proper break in

Tom

^^^What he said.

And you have to remember these are aftermarket built engines we're talking about here, they weren't put through the paces in a factory engine dyno before being installed in a car. The first time they crank, it will likely be in car.

[drivemusicnow]

Originally Posted by Trevor

This statement has just been proven incorrect. Tom is no fool.

What is more full race engines are built with increased tolerances, one of the important reasons being, the lack of opportunity to run them in.

Which tolerances are those exactly? Bearings do not need any "run them in" time as there is really no friction surface except for startup. Also, bearing tolerances on race motors are typically slightly bigger because of much higher heat loads typically found in race conditions.

The ONLY thing on a modern engine that does any "breaking in" is the piston ring to cylinder wall. Tell me, with some technical background, how being easy on the engine will do a better job at creating a good seal?

Also, the worst advice I've heard is to wait 1000 miles before changing the oil. thats 950 miles too many! after those first 50 miles the majority of the piston ring to cylinder bore has been "mated" for lack of a better term. all the tiny metal shavings that this creates are already in the oil. You want to get that out as soon as possible.

As to the absolute statement, you are correct in saying that it was a bit over the top. I'll restate. Almost every "performance" engine. I know for a fact that the LSx series motor, all porsche motors, BMW M motors, most bike motors have all been dyno'd/run on a track before the end product is sold.

This is one of the reasons the c6 LS7 motor almost halted production. During dyno testing of production motors they were getting failures. Turned out to be some supplier tolerances were to tight, as well as some machining that should have been done but wasn't

due to it being late, i'll just supply the link http://www.mototuneusa.com/break_in_secrets.htm

Read over it, keep an open mind. Forgive the author's over enthusiastic nature and slightly lame use of large fonts and bright colors at times. I've seen dyno testing that, while not perfect scientific method, proved this to work.

I'll be breaking in my engine in this way.