Break in procedure

[motox4eva]

Originally posted by 2fun
Ok, here is my procedure for breaking in an engine.
Hopefully I didn't leave anything out.

Generally one tank of gas is plenty for break-in.
Use non-synthetic oil for your first tank of gas. Synthetics are too slippery, and will not allow the rings to break in properly.

There are many different methods as mentioned earlier.
I like to put my motors through several heat cycles prior to taking it out and riding it.
My last two motors I put through 10 heat cycles each, though it is not necessary to put them through that many. My theory is the more heat cycles the better.

I let the motor get warm to the touch and then shut it off. Let it get stone cold before the next heat cycle.
I lightly blip the throttle not holding it at any constant rpm the entire time (vary the throttle). Don't over-rev it, just lightly blip the throttle for the first few heat cycles.

Then I take it out (after 5-10 heat cycles in the shop) and ride it varying the throttle up to half throttle for the first ride. During this 1st ride, I'll vary the throttle (up to but not beyond) 1/2 throttle. Do this for ~ 15 mins.

Let it cool all the way till its cold.

2nd trip out, vary the throttle not going above 3/4 throttle. Ride it for 15 mins, and then let it cool to stone cold again.

3rd trip out, vary the throttle and take it to full throttle, but do not leave it there for an extended period of time. A few seconds at most. Do this for 15 mins and let it cool.

Do a jetting run now to be sure you are jetted correctly. Do this with a FRESH WHITE plug!!
Re-Jet if plug color indicates the need.

Now rip on it giving it gobs of throttle, still varying the throttle. Work the motor hard this time, and generate plenty of heat. Do this for at least another 15 mins.

Your motor should now be broken in.

Run the rest of the gas out of the tank and switch to a fully synthetic if that is what you normally run.
Re-Jet the bike for the new mixture, and you should be good to go!

Please note that whenever taking the bike/quad out on a run, it is ABSOLUTELY NECESSARY TO LET THE MOTOR GET WARM TO THE TOUCH BEFORE RIDING! OTHERWISE YOU RUN THE RISK OF SEIZURE AND YOU MAY HAVE TO RE-DO THE ENTIRE PROCESS WITH A NEW PISTON, RINGS, AND BORE JOB!!!!!

Sorry for the dumb question... but, is that for a 2-stroke or 4-stroke? And, would I do that when I'm only putting in a new piston and rings? Or is that description for when you have a whole brand new bike?

I appreciate it,
thanks,
Drew

[motox4eva]

Originally posted by 2fun
Ok, here is my procedure for breaking in an engine.
Hopefully I didn't leave anything out.

Generally one tank of gas is plenty for break-in.
Use non-synthetic oil for your first tank of gas. Synthetics are too slippery, and will not allow the rings to break in properly.

There are many different methods as mentioned earlier.
I like to put my motors through several heat cycles prior to taking it out and riding it.
My last two motors I put through 10 heat cycles each, though it is not necessary to put them through that many. My theory is the more heat cycles the better.

I let the motor get warm to the touch and then shut it off. Let it get stone cold before the next heat cycle.
I lightly blip the throttle not holding it at any constant rpm the entire time (vary the throttle). Don't over-rev it, just lightly blip the throttle for the first few heat cycles.

Then I take it out (after 5-10 heat cycles in the shop) and ride it varying the throttle up to half throttle for the first ride. During this 1st ride, I'll vary the throttle (up to but not beyond) 1/2 throttle. Do this for ~ 15 mins.

Let it cool all the way till its cold.

2nd trip out, vary the throttle not going above 3/4 throttle. Ride it for 15 mins, and then let it cool to stone cold again.

3rd trip out, vary the throttle and take it to full throttle, but do not leave it there for an extended period of time. A few seconds at most. Do this for 15 mins and let it cool.

Do a jetting run now to be sure you are jetted correctly. Do this with a FRESH WHITE plug!!
Re-Jet if plug color indicates the need.

Now rip on it giving it gobs of throttle, still varying the throttle. Work the motor hard this time, and generate plenty of heat. Do this for at least another 15 mins.

Your motor should now be broken in.

Run the rest of the gas out of the tank and switch to a fully synthetic if that is what you normally run.
Re-Jet the bike for the new mixture, and you should be good to go!

Please note that whenever taking the bike/quad out on a run, it is ABSOLUTELY NECESSARY TO LET THE MOTOR GET WARM TO THE TOUCH BEFORE RIDING! OTHERWISE YOU RUN THE RISK OF SEIZURE AND YOU MAY HAVE TO RE-DO THE ENTIRE PROCESS WITH A NEW PISTON, RINGS, AND BORE JOB!!!!!

Sorry for the dumb question... but, is that for a 2-stroke or 4-stroke? And, would I do that when I'm only putting in a new piston and rings? Or is that description for when you have a whole brand new bike?

I appreciate it,
thanks,
Drew

[Jaybird]

A couple of points I'd like to add to this thread:

Although I would never hone a cylinder wall during rebuild, I would highly suggest that a Scotch-Brite(green) be used to hand rub the glaze from the cross hatching.

I see many folks subscribing to the theory that a synthetic oil is "too slippery" to use for break in. My first thought is that people simply don't understand what is happening with lubrication.
There are two relms of lubrication that are of concern in our motors. Full Fluid Film, and Boundery type lubrication.
Fluid film lubrication is the discription of what motor oil does. It provides a film between the moving metal friction surfaces. This film actually seperates the two metal surfaces and does not allow them to touch. The result is no breaking off of the little peaks that are seen in the metal at the microscopic level. Both conventional dino oil and synthetic do the very same thing as far as fluid film protection of the surfaces.

Once conditions exist that allow these little microscopic peaks to violate and break through the oil film, there needs to be added protection that the oil (either dino or syn) cannot handle. So, mfgs add additional lubrication products to the oil that will either fill in the little valleys of the metal surface, or they will be chem-absorbed into the oxide layer of the metal. The result will protect the metal surfaces even when the peaks touch one another after the oil film has failed.
These products are often refered to as "friction modifiers". I know that this term scares many folks, but it is mostly due to them not totally understanding what they are or how they work.
There are friction modifiers in ALL motor oils, either dino or synthetic.
Some oils simply carry more of one type or another that would classify them as "energy conserving" oil.

To hurry my point along...both dino and synthetic oils only protect to a certain point, they then must depend on other additives to protect. And when we rebuild a motor, there will be some mis-match going on with the rings and cylinder wall that means that there may well be some excessive wear of the ring or wall during start-up and break in, but the choice of oil type does not effect this one bit. Infact, using an oil that has very little additives in the package could result in the "seating" to be more wear than is needed.
Yes, synthetic oil has better shear strength than dino oil, and it also provides protection at higher heats than conventional oils will, but the relm of wear that we are concerned with during "ring seat" has little to do with the fluid film protection of the oil.
As I stated above, it is boundery lubrication that we are concerned with here. So, you can either depend on the additives in the oil to do the protection for you OR you can use a break in fluid while the parts are disassembled. Break in fluids are basically friction modifying products in concentrated form. Some are nothing more than molybdenum, which makes for a fantastic boundery protector for break-in, but there may be issues with certain wet clutches that make moly not the best choice for our sports rebuilds.
Other types of rebuild fluid are actually a chemical that is absorbed into the oxide layer of the metal surface, and when the two surfaces break through the fluid film, they will acutually allow the peaks and craters of the metal to bend away from each other, rather than shear off. What this does is allow the metal to "seat" while keeping the wear during this process to a minimum.
Like I've said, most oils contain these type of products, however during the critical time of a new rebuild, a concentration of these fluids is warranted.

Bottom line:
Synthetic oil will not act any differently than conventional dino oil during break-in. It is the additives in the oil package or the fluid that you coat the surfaces with that counts.

[audacity]

jaybird...you are totally incorrect...engine BI will take longer with the initial use of synthetic oil...more so in a 4 stroke application.

a 2 smoke, i would heat cycle it...yes...then go run the $hit out of it...higher seat pressure=ring seat.

a 4 stroke race engine (what we are talking about)...go run the $hit out of it on dino oil. i like higher zinc content oils for BI. FREQUENT oil changes during the BI process is very important...

we would take superbike engines right to the dyno then right to the track.
GP (2stroke)engines, heat cycle...to the track...those were disassembled no less than 10-15 times a race weekend w/2 new sets of pistons per weekend.

if you have piston to wall contact at any time...the engine was built incorrectly...PERIOD...

my background....years of building superbike/gp engines and racing them at a pro level.
12 years of engine/powertrain development at ford motor co.
5 years as a top offshore racer.

engine builders like to blame BI process,,,not the builder!

you don't break in a chain saw cut'n twigs now do ya

[2fun]

Originally Posted by audacity

jaybird...you are totally incorrect...engine BI will take longer with the initial use of synthetic oil...more so in a 4 stroke application.

a 2 smoke, i would heat cycle it...yes...then go run the $hit out of it...higher seat pressure=ring seat.

a 4 stroke race engine (what we are talking about)...go run the $hit out of it on dino oil. i like higher zinc content oils for BI. FREQUENT oil changes during the BI process is very important...

we would take superbike engines right to the dyno then right to the track.
GP (2stroke)engines, heat cycle...to the track...those were disassembled no less than 10-15 times a race weekend w/2 new sets of pistons per weekend.

if you have piston to wall contact at any time...the engine was built incorrectly...PERIOD...

my background....years of building superbike/gp engines and racing them at a pro level.
12 years of engine/powertrain development at ford motor co.
5 years as a top offshore racer.

engine builders like to blame BI process,,,not the builder!

you don't break in a chain saw cut'n twigs now do ya

I agree with the break-in method. Hard and fast. I am not sure of why a 2-stroke motor needs to be heat cycled and a 4-stroke does not?? Do not the same principles apply to both motors???

[ossagp]

Wiseco says that 10-20 dyno pulls is all it takes to get the rings seated about as well as they are going to in their tests. A dyno pull for them can last 10-15 seconds of roll on from fast idle to the top. That's it.

My take on boundary ("boundery"?) lubrication is this: Boundary lubrication being provided by an additive/additive package to provide at least some kind of lubrication when metal meets metal, primarily occurs on the rings only at the top (where you find the most wear). The piston speed drops, losing the hydrodynamic effect you get from the rings planing on the oil film. On a 4 stroke the oil rings literally never go "boundary". They never have the combustion pressure to make it so. None of the rings do at the bottom of the stroke, where they of course have more oil to begin with as well. Other things such as heat and carbon (pretty abrasive stuff in itself) contribute to that top wear. Yet the rings (particularly the oil rings) need to seat without the metal to metal that the compression rings get.

Kind of a big job for them isnt it?

All my engines whether two stroke gas, 4 stroke gas, or diesel get the drywall treatment. It is just what it sounds like: No prelube on the walls what so ever. Bearings yes,,,cylinder no. An old supercar trick from the 60's, and one taught to me again by those building the most notorious oilers of all time, the two stroke Detroit Diesels.

If you tear apart an engine that the factory sent, (and it doesnt matter which factory you choose), you won't find anymore oil in the cylinder of a new one than it takes to prevent corrosion during storage, and it likely wont look much like motoroil.

Now just warm it up and build some pressure as Aud suggests (and he probably knows it works as well as anyone I can think of.)

[Jaybird]

Perhaps you could explain why you make the claims you do, audacity. Rather than listing your qualifications and expecting us to simply agree.

Why would it take longer to break-in an engine using synthetic as opposed to dino oil? Please be as specific as you can.

If the type of oil used is the determining factor, why the importance of zinc?

Why would there be any difference in the break-in procedure for a 4 cycle as opposed to that of a 2 cycle?

Perhaps you could explain to us exactly what "ring seat" means?

Also...if the machining process were unflawed and tolerences were held...do you feel there is a need to break-in the engine? And if so, why?

You can state I'm totally incorrect, that's fine..but I would expect someone to provide more than "I'm a pro racer and builder, just take what I say and be happy".

I've known scads of "pro racers" who thought they had it all figured out too.
Some actually were close to having it all figured out. LOL....

[Jaybird]

Heat cycling has the same importance with either type of engine.
All engines should be brought up to temp before being put under load.

What some fail to understand is that there is a BIG difference in a machined engine and a production model engine.
With a production engine, the tolerences aren't near as close as what the machine shop can hold. Mass production just won't allow it. Because this wide tolerence window exists in the mass produced engine, we need to have a period of run time for things to wear into one another, specifically at the cylinder wall and the rings. These mismatches are going to wear into one another no matter what oil is used. And as far as time is concerned, there is no way anyone can predict the time needed to wear in a cylinder simply by the choice of oil.

What can be predicted is what sort of condition the metal surfaces of the cylinder walls and rings will look like once they have worn into one another.
If an oil that has very little barrier additives is used, be it organic or synthetic...no matter...the metal will wear differently that it would if a heavily barrier additive fortified fluid was used.

When the metals molecules shear one another away, which is what is actually happening during break-in, they can shear each other nice and clean, or they can grab at each other and rip and tear themselves away.
A good barrier fortified lubricant will allow the metal to be sheared off cleanly, leaving the best possible surface with the least amount of metal reduction.

And yes, even the motor that had the weak oil package will eventually wear itself in to a similar condition to the motor that used good oil, but it will have taken more metal to get there. Which means the ring gap is larger, which means less compression, which means less horesepower.

I still contend that it makes no differnce if organic or synthetic oil is used. It makes no difference, because the things I'm describing happen at a level that is past the fluid film that either oil can provide. Break=in happens at the microscopic level.

Now, the race engine that was hand machined. It should be ready to race or the machinist isn't worth his salt. Of course it may be the "builder" that could be to blame if he fouled something up bolting parts together.

[paskracing77]

GEEEEEEEEZZZzzz i was gonna break in my new top end tommorow with amsoil interceptor synthetic oil but now i don't know if i should..! what do you guys think?