Thinking about engine break in, diesels & gensets

[JHZR2]

My accord hybrid is still in break-In mileage range where they say to drive more gently (I always drive very gentle so not a problem). But it got me thinking. One school of thought recommends some decent throttle to build high cylinder pressures, followed by some high engine breaking to seat the rings (IIRC).

I realized while driving that as soon as I let my foot off, the engine shuts off, and the generator provides load.

I have no practical way to really do engine breaking, lots of vacuum, etc.

But then I got to thinking - my car is similar to a diesel electric locomotive. The engine can be generating and fully mechanically decoupled from the wheels. It is. And again, when I let off the throttle, it regenerates, it doesn't pump sit by the engine.

So, all that said, is the whole closed throttle, high vacuum to seat the rings thing real? I mean, hybrids can't do it (unless it's done in the factory). Similarly, diesels do g have the high vacuum or throttle, and gasoline generators, even if they have a throttle, can't coast down like in a car.

So what gives??

 

[CT8]

Just use the car don't worry about this or that . People worry too much about things that don't need to be worried about.

 

[linksep]

No, AVOID high vacuum during breakin! Pressure helps seat the rings against the walls, vacuum means low ring tension against the walls. Low tension = burnished walls instead of worn-in walls.

 

[JHZR2]

Originally Posted By: linksep
No, AVOID high vacuum during breakin! Pressure helps seat the rings against the walls, vacuum means low ring tension against the walls. Low tension = burnished walls instead of worn-in walls.


I was thinking along the lines of these:

First from the famous motune website;
Quote:
NOTE: If you use a dyno with a brake, it's critical during break - in that you allow the engine to decelerate fully on it's own. (Don't use the dyno brake.) The engine vacuum created during closed throttle deceleration sucks the excess oil and metal off the cylinder walls.

The point of this is to remove the very small (micro) particles of ring and cylinder material which are part of the normal wear during this process. During deceleration, the particles suspended in the oil blow out the exhaust, rather than accumulating in the ring grooves between
the piston and rings. This keeps the rings from wearing too much.


And elsewhere...

Quote:
"Letting the engine bring the revs back down", otherwise known as vacuum pulls, is key if you ask me. Any time your accelerating, there is a decent amount of load on the rings. And if your are a little spirited about it, even more so. But in general, the rings do not get that much pressure in the opposite direction in normal driving, without doing the vacuum pulls..

http://www.6speedonline.com/forums/tech-how/48047-1-day-engine-break.html

Quote:
Each time you hit 5500-6000 rpm, snap your foot off the gas and let the car coast down to 2500 rpm while in gear, to pull high vacuum in the cylinders. Repeat this step about five times and you should have a nicely mated set of rings and cylinders.

https://www.flyinmiata.com/tech/breakin.php

Quote:
During driving break-in, vacuum pulls are necessary to seat the piston rings. This involves accelerating with light load, letting off the throttle, and letting the engine slow the car down.

http://www.examiner.com/article/how-to-break-a-new-engine

And so on...

 

[Garak]

Originally Posted By: JHZR2
Similarly, diesels do g have the high vacuum or throttle, and gasoline generators, even if they have a throttle, can't coast down like in a car.

This is BITOG in a nutshell. It's these little concerns that give us OCD types nightmares.

 

[Quest]

Originally Posted By: linksep
No, AVOID high vacuum during breakin! Pressure helps seat the rings against the walls, vacuum means low ring tension against the walls. Low tension = burnished walls instead of worn-in walls.


Apparently, you never heard of the horse "whipping" method of breaking in the rings, where rapid acceleration puts combustion pressure on the compression rings; snapping the throttle shut creating high vacuum (engine braking) to help bring in the oil from the wall and ring gap to lubricate the rings and also aid in breaking in the other side of the piston rings.

new piston rings typically comes to complete broken in in a matter of a few miles when done this way, and will typically last hundreds of ks worth of trouble-free miles.


Q.

 

[JHZR2]

Originally Posted By: Garak
Originally Posted By: JHZR2
Similarly, diesels do g have the high vacuum or throttle, and gasoline generators, even if they have a throttle, can't coast down like in a car.

This is BITOG in a nutshell. It's these little concerns that give us OCD types nightmares.

No nightmares here. In reality I cant control the operations or the "vacuum down" process on the engine on my car. So it really is more of a curiosity for discussion of engine operations and technology and break-in.

Nothing will change how I break in my engine, because short of not doing WOT runs, there is little control I have.

 

[userfriendly]

Cylinder wall finishes ain't what they used to be.
That and coated rings make for an almost instant break-in.
A nice 3 hour road trip to PA and home again should do it.

Edit; And when you get home.....drain out that TGMO if you haven't done so already.

 

[JHZR2]

Originally Posted By: used_0il
Cylinder wall finishes ain't what they used to be.
That and coated rings make for an almost instant break-in.
A nice 3 hour road trip to PA and home again should do it.

Edit; And when you get home.....drain out that TGMO


Dont think I have TGMO in there

 

[userfriendly]

Oops, I was thinking a Prius.

 

[Garak]

Originally Posted By: JHZR2
No nightmares here. In reality I cant control the operations or the "vacuum down" process on the engine on my car. So it really is more of a curiosity for discussion of engine operations and technology and break-in.

Well, it's a darn good question!

 

[Vikas]

Quote:
Edit; And when you get home.....drain out that TGMO
Does Honda Owner Manual request to keep the oil for the full OCI?

 

[RoadRaceJosh]

The machining in that engine is so superior to the old days that those stated break-in procedures are obsolete. Follow the owner's manual and enjoy your new car.

 

[Shannow]

Originally Posted By: Garak
Originally Posted By: JHZR2
No nightmares here. In reality I cant control the operations or the "vacuum down" process on the engine on my car. So it really is more of a curiosity for discussion of engine operations and technology and break-in.

Well, it's a darn good question!


Will have to find the O and M manuals of one of the big diesels at work, but IIRC, it was a couple of timed blocks at steadily increasing loads, checking for noises and leaks, and then a heat run of a couple of hours.

 

[Garak]

Sounds interesting. Maybe more is done in the factory with respect to break in with things like hybrids.

 

[SatinSilver]

Not sure if it still states in the Accord owner's manual to avoid cruise control during break in. And to vary the speed on the highway. There's some interesting stuff in the O.M. Probably even more so with the hybrid.

In the previous Accord hybrid, 2006-07 a 3 liter V6 engine was used for performance reasons. When most buyers were looking for economy. Glad to see Honda using a much smaller engine.