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Oil blowing out of breather...??

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Old 12-24-2000, 03:37 PM   #1
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Oil blowing out of breather...??

Puzzling problem. Put a new motor in my friends El Camino a month ago. Includes TrickFlow heads and running about 10.2:1 compression. Here's the problem; ever since the install, oil has been blowing out of the valve cover breather. We checked the PCV valve (new) and it is good, and is connected to the right port on the carb. The breather was an Erson chrome push-in style that was on the old motor. We installed a new Chevy chrome push-in breather. Same problem. We installed another PCV valve. Same problem.
Maybe we're overlooking something.
Any suggestions?
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Old 12-24-2000, 05:17 PM   #2
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I have absolutely no idea what the problem is, but may have a way to fix it anyway. They make valve covers with baffles to keep the oil from splashing in there so much and to keep the rockers oiled better. If you can not figure out any other way to stop it, this may be a good idea. One draw back to these valve covers, however, it takes about 2-3 minutes to put in each quart of oil.

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Old 12-24-2000, 05:20 PM   #3
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My guess is a lot of blowby...if it was a fresh rebuild, it may take a while for the rings to seat themselves to the bore; or it could be the rings were incorrectly gapped (ie. too large a gap); or even the wrong oversize pistons: .030 over into an .040 over bore.


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Old 12-24-2000, 05:51 PM   #4
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i was thinking rings installed up side down? if it's a new engine i would give the rings a chance to seat.

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Old 12-24-2000, 05:54 PM   #5
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are you using synthetic oil for the break in? you need to use natural oil in order for everythin to seat properly...

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Old 12-24-2000, 06:22 PM   #6
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It's a new motor. Built and dyno'ed by a local speed shop. Has about 900 miles on it at this time. No synthetic oil. Is using what seems to be an abnormal amount of oil, but not blowing out the tailpipe. Runs VERY strong, just this breather problem.
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Old 12-24-2000, 09:59 PM   #7
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I had this problem with one of my motors. The cure for me was this. I had the pcv in the back of the valve cover going to a port on the rear of the carb. This motor didnt like it and puked oil also. I moved the pcv to the hole that the breather was in. It was in the front of the cover and it made sense that the blowby would come out the tallest part of the valve cover.This solved my problem. The breather is in the back and the pcv is in the front.

[This message has been edited by 87Z-ya (edited December 24, 2000).]
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Old 12-25-2000, 01:14 AM   #8
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Pull out the Dipstick and Rev the engine, Do you see atomized Oil Blowing out ?

If So, You got some Massive Blowby.

if Not, Then you are prolly okay, Just get a Breather With a Foam insert In It to seperate the Oil My Buddys Nova is pusing 500Hp and it Blows the Breathers out On Occasion

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Old 12-25-2000, 07:52 AM   #9
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Had the same problem, solved by putting both beathers on the driver side.

No PCV...screw that emissions crap.

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Old 12-25-2000, 01:58 PM   #10
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PCV's are not emissions crap! They take harmfull combustion gasses out of the crankcase before they contaminate the oil and raise it's acidity.

Do your valve covers have baffles in them were the breathers go? If the valve covers are cheap then they won't have baffles and oil will puke all over the valve cover. Get a GOOD set of valve covers with baffles and your problem should go away. If it does'nt then you have ENGINE TROUBLE.

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