Blow-by

[terrible one]

I think I've got too much blow-by. To start this is a newly rebuilt engine with 162 miles on it so far. I would think the rings were pretty much seated by now. When I first took it out and started breaking it in I would get some smoke out of the exhaust at full throttle, etc. which eventually lightened up and went away, leading me to believe I had successfully seated the rings.

Yesterday when I got back from cruising and shut her down I noticed some oil on the valve covers below the breathers. I'm running cheap parts store "chrome dome" breathers on each side, and both of them seem to have a bit of oil misting out, because it's on the valve covers below the breathers and on the bottom side of the breather itself. There was even a little bit drizzling from the top of the dipstick tube.

From what I know, this is usually the sign of an old worn out engine, not a fresh one  

So, what do you guys think the problem could be?

[68charger440R/T]

I had those cheap chrome breathers on my car and they leaked and smoked like crazy so i bought the ones that look like a K&N filter and it solved the problem, hasn't leaked or smoked since i switched them.

[Purple68]

Maybe try installing a PCV instead of 2 breathers.

[A383Wing]

Maybe try installing a PCV instead of 2 breathers.

[terrible one]

So this wouldn't really concern you guys? I was freaking out thinking I had a ring sealing issue or something really bad

[greenpigs]

   I would have put a little more miles on it before hammering it, but it sounds like that is not the problem. I would run a PCV valve also instead of 2 breathers & then clean it up & see what happens.

[Cooter]

So this wouldn't really concern you guys? I was freaking out thinking I had a ring sealing issue or something really bad

As much as you tend to like to "Ring that 383 out", I'm surprized the rods are still in it. ...
This "Blow by" thing goes right along with the "Oh sh*t, I gotta blown head gasket" after the oil filler cap is pulled and that milky, condensation has formed under it....No, I don't think you have a ring problem, but a cheap breather problem...I just had explain to my kid after installing his freshly painted up, detailed all to hell, 440 that this is the last time it will EVER look as good as it does right now...BTW: I don't think the rings are fully seated with only 162 miles on it...I'm thinking at least one oil change (3000 miles), maybe two before they totally seat...See why you shouldn't be out there screaming that thing?

[terrible one]

Thanks Cooter hopefully now I will sleep tonight.

I was just tryin' to see how many RPMs it took for the pistons to swap holes so I would know when to shift at  Really though, I was freaking out, I always assume the worst. That'll teach me to tone it down a little bit I guess! I don't know what I would do if I broke my 383! I guess I'll just wipe up the little mess and be a bit easier (sometimes  ) and see what it's like after I put a couple thousand miles on it.

[FLG]

Are the valve covers baffled? That will cause oil misting problems 

[firefighter3931]

Jackson, as Franks mentioned ; are the valvecovers baffled ?

The problem with those old M/T valvecovers is that the oil/breather holes are placed in the incorrect location. The holes should be between the rocker arms not directly above them. What happens is that oil is flung off the rocker arms directly towards the openings and if you don't have baffles....

The newer valvecovers allways have the holes more inboard for this very reason. All you have to do is compare an old M/T valvecover to a newer MP or other aftermarket VC and you'll see the difference. 

If your breathers are the cheapo chrome stuff that vents from below then there will be some oil misting...especially if there is no baffles in the covers. 

Try installing baffles and use a K&N push in style breather that vents from the side rather than below. 



Ron

[terrible one]

Thanks guys. The valve covers do have baffles in them, but I know exactly what you are talking about with the position of the holes Ron. I will try to get some better breathers eventually but until then I will just try to keep it clean. I took one of the breathers off and it's just got what looks like foam in there, some of which has already melted a bit on the header side. So I think you guys are onto something. These breathers let any oil that gets to them just drip through the foam. I'll put quality breathers on my to do list and hope for the best I guess!

[68X426]

Try installing baffles

Ron, or anyone, how do you install baffles? Is it just a matter of welding on a custom made bracket and plate? Is there such a thing as too big or too small, do we just aim for what "looks" about the right size?

[firefighter3931]

I'd use something like this : http://www.summitracing.com/parts/MOR-68810/?rtype=10

These are slightly raised and will allow for drainback once the engine is shut down. There's no foam to melt either  


Ron

[firefighter3931]

Try installing baffles

Ron, or anyone, how do you install baffles? Is it just a matter of welding on a custom made bracket and plate? Is there such a thing as too big or too small, do we just aim for what "looks" about the right size?

Most of the aftermarket VC's have bosses cast into the roof of the cover. It's simply a matter of installing the baffle with a sheet metal/self tapping screw to hold it in place. The baffles should cover the hole completely but an additional inch on both sides won't hurt. 

With a sheetmetal cover you can tack in the baffles with a welder.


Ron

[68X426]

Thanks for the tips.

[terrible one]

I'd use something like this : http://www.summitracing.com/parts/MOR-68810/?rtype=10

These are slightly raised and will allow for drainback once the engine is shut down. There's no foam to melt either  


Ron

Thanks for the additional info and link Ron.

Now the hard part is putting the $40 up for the breathers instead of dumping it in the tank

[Kern Dog]

Some of the responses here will lead you to believe that running the fresh motor hard is a bad thing. I have read more and more that the best way to seat the rings and insure that oil burning is minimized is to actually drive the car hard. Start it up and break in the cam. Change the oil and start it up again. With the engine up to operating temperature, take it out and run it hard. The increased combustion pressure forces the rings against the cylinder walls. These theories also contend that driving easy during the first few hundred miles does more harm than good to an engine that WILL see full throttle later because the rings were not properly seated for it.

[doctor4766]

I was given similar advice too, and although I didn't thrash the pants off my new motor I didn't baby it either and it doesn't appear to have been detrimental to it's normal operation now.

[BSB67]

It depends on the type of rings used and the finish of the bores, generally speaking.  Most hi-performance application using a moly coated top ring with the appropriate finishing does not really need much break in.