Proper engine break in...

[Nate1]

I have heard both sides of the story, either you should get on it with a fully warmed engine asap to properly seat everything and get a full break in ( http://www.mototuneusa.com/break_in_secrets.htm ), or you should take it easy granny style and constantly vary your engine speeds for a good long distance (owner's manual style).

So, from a tech's perspective, which is the correct method? I can see the logic in both sides really, so I'm somewhat confused. I mostly want to believe the manufacturer and the research that they do, but then again there are definitely tricks of the trade that are not well known but do work.
-----Nate

 

[rookieshooter]

Interesting article. I assume your talking about an engine in a brand new truck. I would do it just like the owners manual, but just take it to a little higher rpm. But on an enginge built for you, I think a lot of it has to do with how your engine was built. Was a rougher honing stone used. Or a finer one like he said that is used on the newer engines. What is the composition of your rings. Moly or could they be iron. But do not break it in with no load like in a garage. I would allways take the rpms a little higher because I like the idea of the rings going up and a little higher in the bore due to rod stretch which is important if you plan to run higher then normal rpms. This was more true in aluminum rods. Also when building my own engines I had the machine shop use a torque plate on block so there is stress all around the cylinders just as if a head was bolted to block. Then it was put on a Sunnen honing machine. The block does stretch when heads are torqued on. If you are talking a built engine for you make sure you prime the oil pump so oil is allready in all passagways. At one time I had small holes drilled in the top of the piston angling back behind the rings to really seal. This was on all out racing engines. And sometimes I had step rings that let the gas go behind the rings. The guy is right about the spring pressure on the rings. That is not what seals it. It's the gas. You can also use a ring that does not expand much so a smaller end gap can be used thus higher compression. I better stop. My heads spinning.

 

[spindlecone]

New rebuilt engine? or new vehicle?.If a new vehical, use the manufactorers recomendations, vary your speeds for 1K miles.
than change the oil, than change it again at 3 k miles.
If a crate motor or a new rebuild, the most important part of a fresh startup is your Cam bearings, run it at about 1500 RPMs for say 10 mins, shut it down, change the oil and filter, than slowly break it in.

 

[Nate1]

This would technically be for my new GTI, but it applies to any "new" 4 stroke vehicle I guess...

I have been planning on following the slow and steady rule because it seems like the patient route is almost always the better one, and I have done the slow and steady method on a few 4 stroke boat motors which all run smooth as can be, but I just figured I would get some opinions from those "in the know".

 

[rookieshooter]

This would technically be for my new GTI, but it applies to any "new" 4 stroke vehicle I guess...

I have been planning on following the slow and steady rule because it seems like the patient route is almost always the better one, and I have done the slow and steady method on a few 4 stroke boat motors which all run smooth as can be, but I just figured I would get some opinions from those "in the know".

I would do exactly as the book says. IMO it would be benefical to break it in on longer runs if that is possible. That way any condensation that forms when you first start it up will be burned off and that is just one contaniment you don't need. Now the rings and bearings have good oil.

 

[Aussie Explorer]

Key points when braking in an engine

Don’t allow it to idle
Don’t thrash the **** out of it
No constant speed driving
No shot trips and try to stay out of heavy traffic for the first 200k’s.

Oh and despite what manufactures are saying now Change the dam OIL somewhere between 1000-3000 k’s or 600-1500 miles

For example my dad just brought a new ford, according to Ford first oil change at 15,000k.

2 possibilities for this> 1. The machining is unbelievably good and clean so the oil change is no longer required, or 2 the engine is Pre Run in.

Now I doubt ford Pre run in Engines so I am guessing in standard Ford stile they think that there machining is that Good, Which I find hard to believe on anything but a Custom hand Built engine assembled in a dust free environment.

 

[Nate1]

Apparently VW (and other mfgrs, possibly Ford) pre-fill the car with oil containing some special "break in" blend, as well as a special filter. I dont know if this is true or not, but I have heard that your first oil change on a new engine should be 1/3rd the regular int.

 

[CDW6212R]

Wow, so many different opinions, and most are a poor interpretation of correct procedures and reasons. Sorry guys, but below is the proper break-in theory.

A new engine needs oil throughout the engine immediately at the first start-up. The rings and non-roller lifters are the most sensitive parts when new. They must be very carefully broken-in. They must have a proper wear pattern created, or else they will either fail prematurely, or allow too much blow-by in the cylinders(oil consumption and loss of power).

Roller lifters don't have those special lobe problems, they are a non issue for break-in.

If the rings are not seated properly, from say excessive loading(WOT), they can become "glazed", just like too much heat in new pad/roptors. They need varying RPM's to evenly create a proper wear pattern in the cylinders. That maximizes ring life, and power.

Bottom line, prime the new engine just before starting. Use a straight weight oil(40W) for the initial break-in period of 15-20 minutes. You don't want to wait for low viscosity oil to heat up(thicken). Do not allow the engine to idle at all, or run under 1500-2000 for that entire 15-20 minutes.

It is a two person job, one to manitain the engine running at 2000RPM, and one to top off the fluids, and set the timing.

Change the oil and filter immediately after that initial break-in period. Change to the proper weight oil, and change the oil/filter again at 1000 miles, and not synthetic oil. Synthetic oil will keep the rings from seating properly. Use regular oil for at least 4000-5000 miles.

This isn't a mysterious procedure, with magic, or unknown reasons. It's common sense learned by professionals decades ago. Don't get caught up by the "in" thing you hear about, without thinking about the why. Good luck all,

 

[94WhiteEB]

Its all a bunch of crap. Let it warm up and cycle for a minute, then drive it like you'd normally drive it.

 

[ExplorerDMB]

If it was a performance motor, I'd follow CDWs way. I'll take the extra time and money to make sure its right when I already spent a hunk of change building a bad a$$ motor

-Drew

 

[CDW6212R]

Engine break-in is about keeping oil on fragile parts when they are brand new. The piston rings need oil splashed up into the cylinders continuously when freshly machined/honed. Non-roller camshafts need that oil also very much when brand new, they are creating a wear pattern that is critical to any lifespan. Without proper oiling after startup a cam can be ruined very very quickly. More oil reaches these parts at 2000 rpm, that's the point. Good luck all,

 

[rookieshooter]

Of all the preparation of building a high performance mill. The above tool that I use just before initial fire-up, may just be the most important.
It's all about reducing friction on those critical new parts. And that's all about the oil. Now even before the oil even gets to those parts like cam lobe and wall surfaces of those lifters. They are coated with a moly lube.
That brand new rebuilt 302 that I just fired up the other day for the most part was above 2000 rpm's. When we let off of it the idle was 1100.
It pulled 22 inches of vacuum. And that's before the rings are seated