Drop the freaking wrench already!

[95tsi]

Sounds like this motor came from the same guy I got one of my cars from... Some people just shouldn't try when they clearly have no clue or concept of what to do.

[dumb_ricer]

Wow, seems like a real garage mechanic to me. I bet they didnt use a torque wrench at all, just "eh fuck it, snug um up reely good'n it'll be yall rite".

And Mike, about what you were saying about staggering the rings, have you noticed them being un-staggered when pulling motors apart. From what I have seen, it seems like after break in, the rings would stay pretty close to the part of the cylinder wall that they broke in on in the first place. I know that now machining tolerances are very close, but you would think that the rings would wear in to a point and kind of lock themselves where they are? I dunno, just an observation.

[Raptor]

Nice thought, doesn't quite work that way. They don't wear enough of a groove in the cylinder wall to maintain a position relative to their install. They actually do have a tendency to line up to some degree, not always, but it is common to find them in a row on a motor that has run for a while. The main point is that they are completely free to spin in any way they choose and there is little short of pinning them that will stop it. It is good practice regardless to stagger them and for that reason it should be done. I always have and always will. If there is any chance they will maintain position, it is worth the few extra seconds ;)

[dumb_ricer]

Interesting, then I have another question!

What is a modern break in actually doing then? If the rings dont "wear into the cylinders" then what is a modern break in actually doing? Assuming all the Machine work is correct and true, then what is actually "breaking in" on the motor that manufacturers and even professional race engine builders still suggest a break in? Assuming that the rings will always turn inside (havent seen anything proving they do or don't) then all that the rings and cylinder walls are doing is smoothing themselves out. In that case, I only see a break in procedure lasting 10-15min of 2000rpm and then a few times under load and the motor should be 99percent "broken in". Hmm, time to do some more research for me.

(And yes, every motor I have/will ever build will get the rings staggered)

[JET]

The rings do seat against the cylinder walls, but it isn't anything that would wear a groove in the cylinder wall. That is the main thing that happens on break-in.

[Raptor]

As mentioned, the primary reason for break in is getting the rings seated in. Before modern plateau honing methods, it took considerably longer as it was the rings job to level off the peaks left by the honing process (microscopic) Of course that wears the rings considerably more as well. Now days the rough honing is followed by a much finer hone that levels the peaks off so most of that process is already finished. In cases where plateau honing is used, the break in period is very quick almost as soon as the engine is warmed up. definately after the first few pulls. The main point is that in either case, the rings do not effect the cylinder wall nearly enough to leave any "guide" or retaining type ridge for the ring gaps to maintain a stagger. Just doesn't happen. In fact like I mentioned, they have more of a tendency to line up. I pulled another stock engine apart this week that 3 of the 4 pistons came out with all the ring gaps lined up. It had over 150K on it.

BTW, it is worth checking with whoever does you machining to see if it has been plateau honed so you know what is appropriate for break in. It seems like there are still quite a few shops that don't use it. They really all should.

[Enes]

you better listen to the old man, he knows it all!

afterall he is edumacated by the best!

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=7970639347&category=6032

[Raptor]

Funny man E. That book just showed up, and like I expected, there were a few valuable bits of info in it. No one person knows everything, it should be everyones goal to be the best they can at whatever they may be trying to do which means lots of research in every concievable area. That specific book is a good reference regardless.

But more direct to the honing thing, that info has been in my old brain for more than a few years ;)

[Pushit2.0]

On Randys motor I just built we did a compression test after warming the car up for the first time, so 5-6 min of run time and already had 175 across the board. And checked on the dyno after 45miles(and 500+whp at the time) and it was 190 so I would say breaking in a motor would have somthing to do with how long it will last, not just to get compression and hold power.

~John

[Raptor]

As usual, this thread has gone way off topic, so considering that it sounds like there is enough question as to why breakin is important and what it's primary reasons are etc maybe we should start an engine building basics thread in the tech area and hit all these topics. People obviously need the help, this week we pulled apart 90LaserRST's motor and of course found stupid mis-informed mistakes on it as well. (Not done by him I am told)
but none the less if people are going to insist on doing this stuff themselves, maybe they should have a resource where they can get the info to do it right and understand why.