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Old 10-10-2014, 08:43 PM   #1
Hogger54
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Valve cover venting. Is this normal?

It's got new oil, and it's not from the paint. Is it normal to have steam/smoke vent from the valve cover like this?
I ran it for probably 15-20 mins.

http://youtu.be/17DTCc1cLTs?list=UUb...VOKkK41q2D8dwQ
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Old 10-10-2014, 08:51 PM   #2
dwcsr
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Re: Valve cover venting. Is this normal?

Thats what those vents are for. If you closed them off the crank case can fill with vapor and under certain situations explode. Options are to get a later cover with no vents and use a PVC setup
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Old 10-10-2014, 09:20 PM   #3
Hogger54
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Re: Valve cover venting. Is this normal?

Ok, good. Just haven't really seen it like this, and wasn't sure if it may be from lack of oil.
I finally got the engine tuned, and running pretty well. So after a short drive, this is what I saw.
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Old 10-11-2014, 11:30 AM   #4
whitedog76
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Re: Valve cover venting. Is this normal?

Perfectly normal.

The draft tube doesn't create any vacuum until about 35 MPH to draw out the crankcase gases.

Later 235's used an actual vented breather and non-slotted valve covers.

You can always do a PCV upgrade also.
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Old 10-11-2014, 03:25 PM   #5
mr48chev
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Re: Valve cover venting. Is this normal?

That setup is also a reason those engines were due for a rebuilds at about 30K. Going down the road those slots served as the crank case breathers for air to go in and flow though the crank case and out the draft tube. With no filters or screens to catch the dirt in the air the dirt went into the engine with the air and caused premature wear.
The fumes coming out the top are due to no air going past the end of the draft tube to draw them out into the airstream as Whitedog76 mentioned in post #4.

What also makes that setup undesirable is that every time you get caught in traffic with your significant other riding in the truck with you she will fuss about smelling the fumes in the truck.
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