Benefits of a hard break-in discussion

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Ill be breaking in a Buick 340 I just rebuilt for a '67 GS340. See if we can get some non ILSAC Oil in there Likely again as i always rec 4T motorcycle stuff, or maybe just SAE30 plus the zdp break in sauce. I'm all for loading the engine, but not for LONG periods. maybe 3-4 second WOT under 4000 rpm then cool down for a few mins before then next run up.
 
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Imagine that, he drops the FF on a new vehicle in 500 miles............... hide popcorn I'm going to stick to what I've been doing all along.
 
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Come on! We all know the engineers write the owners manuals (must be in their spare time) and we also know engineers only do what's best without compromising anything. These people are not affected by company policies, management, market, marketing pressures etc. They just sit in their little cubicles and engineer away, and write owners manuals after that, or maybe during their lunches, I'm not sure ,as internet lore has not touched on that yet. wink
 
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So, Honda for one is absolutely wrong. They load their engines with molybdenum (from assembly lubes) at the factory, suggest leaving the factory fill in for a normal service interval and tell the owners to avoid hard acceleration for the first 500 miles. I've done this with several new Hondas and never had an oil consumption issue let alone a "destroyed" engine from my neglect. And I really doubt Honda is the OEM running the engines at WOT when they come off the assembly line.
 
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Originally Posted by KrisZ
Come on! We all know the engineers write the owners manuals (must be in their spare time) and we also know engineers only do what's best without compromising anything. These people are not affected by company policies, management, market, marketing pressures etc. They just sit in their little cubicles and engineer away, and write owners manuals after that, or maybe during their lunches, I'm not sure ,as internet lore has not touched on that yet. wink
Don't forget the corporate legal department
 
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just bought a HF predator 6500 w. Owners manual sez to break in engine with a 3 hr run at a "moderate" load. Oil spec is 10w30. Recommended OCI is 20 hrs. I'm changing oil after break in. Just to see if there is any glitter. There was little if any visible glitter from my first Predator. grin2
 

4WD

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Meh … nothing wrong with following the builders owners manual when it comes to break in. Been doing that for decades (do like an early 1st change) and never wound up with an oil burner even with engines that internet "know it alls" say always burn oil.
 

buster

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How come this is still a debated topic in 2020? And why is Dodge the only company that states in their manual that brief full throttle acceleration helps ensure a good break-in? Last, why am I so obsessed with this topic? LOL!
 

Ws6

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My Z06 had very specific instructions. None of it involved WOT until 1000 miles. Also, the rings are pressed against the walls most when the engine is in vacuum. Engine-braking from a sensible rpm is the way. Not revving to the stratosphere. During break-in of my Z06, I noticed for the first few hundred miles, a lot of soot on the tail pipes, as well as oil consumption (about 1/2 a quart total, in 1K miles). After about 7-800 miles, the soot stopped. I tracked oil usage after the first change I did, at 1K, and it never used another drop that I could tell. The engine definitely needed breaking in. Beating on it wasn't the way it was to be done. When you do this, you spike surface and system temperatures beyond normal maxes, because the increased friction of rougher surfaces will do that. After the engine is broken in, these surfaces play nicer. The same happens with the transmission, and the diff gears. The real bug in the ointment is the brakes...which should be broken in HOT for some systems (carbon fiber rotors/ceramic pads are a perfect example). Gears like a gentle break in, brakes like a hard break in, and engine components vary, but I have found a sensible break in is best (driving in moderate city traffic, and engine braking, is a great method, actually).
 

buster

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A GM engineer that at one time was a member on this site said high load was good for break-in. You can do that without high RPM. I think that is most ideal.
 

buster

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Originally Posted by BrocLuno
Are we breaking in a race engine, or a street engine ... Are we trying for 600 mile life at 800 HP, or 300K at 150HP ...
He was talking about street/stock cars.
 
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I guess I've been doing it wrong for 40 some odd years. I take it easy during the initial miles. I haven't had a oil burner yet. Break in oil? Maybe for special engines.
 

buster

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The reason I'm interested in this is because in some cases how you break-in an engine can have a dramatic impact on oil consumption and compression/hp.
 
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Do they break in cop cars? I bet they pin them to the floor every chance they get.. and still live on to become taxis.
 
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Originally Posted by buster
The reason I'm interested in this is because in some cases how you break-in an engine can have a dramatic impact on oil consumption and compression/hp.
Can you please explain this with specifics?
 

Bud

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Originally Posted by Danh
So, Honda for one is absolutely wrong. They load their engines with molybdenum (from assembly lubes) at the factory, suggest leaving the factory fill in for a normal service interval and tell the owners to avoid hard acceleration for the first 500 miles. I've done this with several new Hondas and never had an oil consumption issue let alone a "destroyed" engine from my neglect. And I really doubt Honda is the OEM running the engines at WOT when they come off the assembly line.
People are going to do whatever they want, including following advice from someone they don't even know on this board. I followed the advice from Honda when doing my first oil change. Just my opinion that they might know what they are talking about.
 
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