Author Topic: Blow By  (Read 4619 times)

Damon

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Blow By
« on: August 31, 2009, 04:20:52 PM »
Drove the Camaro this weekend and smelled oil burning.  Turns out the drivers side valve cover breather is leaking oil on the header and in the slots on the top of the valve cover.  I removed the breather to see if this valve cover had any type of a baffle, it does not.  So do you know if I have the wrong breather or does someone offer a baffle for these valve covers?

Thanks,

Damon
Damon

Stingr69

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Re: Blow By
« Reply #1 on: August 31, 2009, 06:02:30 PM »
Old problem that never goes away. The covers look like stock alum but might not be OEM or may have been modified.

My advice is to get some stock baffles and set up the PCV like stock so it will work properly. You may have a big valvetrain issue under those covers so the stock baffles might not fit easily under there. There are aftermarket baffles with extra clearance that can be attached but they are probably not as good as the stock setup for oil mist control. Get the stock elbow and plumb it to the air cleaner base with a proper stepped rubber hose. Then and you can forget about the oil mist vapor collection problem.

Smokey Yunick came up with a setup that uses a puke can with both valve covers tied together. Not cheap, pretty or easy but for competition it was a solution to the problem. Stock setup is probably the best. :)

-Mark.

Oregonjam

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Re: Blow By
« Reply #2 on: September 01, 2009, 02:29:22 PM »
Not all aftermarket baffles are the same. GM engineers spent alot of time developing their baffle designs. I recommend sticking with stock when ever you can. I had a repro valve cover setup installed and had a similar problem with baffles. I changed to a different set of valve covers that had a 'stock' baffle design with the OEM PCV setup and the problem was solved.

With out baffles installed it is difficult to say that it is blow by. Itis probably just splashing form the rockerarms being oiled. If it is persistent after baffles are installed then performa leak down test to see if you have a anissue with blow by. If it tests well it could be a valve guide seal as well.
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John

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Re: Blow By
« Reply #3 on: September 03, 2009, 04:01:30 PM »
Your current setup has no crankcase ventilation - only pressure relief, which is why it's blowing oil. Can't see where the hose goes from the PCV valve/elbow in the pass. side cover. Best to stick with the stock PCV layout - it was developed at great expense for a reason. The driver's side valve cover should have the oil fill cap and the PCV valve (with a hose to the big PCV nipple on the carb), and the passenger side valve cover should have a grommet with a large hose to the air cleaner base; do that and you won't have any more oil issues.
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