Y block crankcase vent

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Apr 16, 2007 | 02:45 PM

dreamd0g

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Joined: Mar 2007

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Y block crankcase vent

Well the rebuild on my 239 is going very well. Ram horns in hand and all. My next question for anyone who can help concerns the crankcase breather. Mine has damage beyond repair. The question I have is this: With a vented filler cap, why does a guy need one at all? Can I cap the hole in the block and run w/o it? thanks

Apr 16, 2007 | 03:57 PM

fking1

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Joined: Jul 2004

Posts: 825

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From: Michigan

IMO, It is needed to vent from the crancase. The filler cap will vent only the rocker cover area. A buildup of pressure in the oil pan may cause a problem as there would be no holes except the piston rings to vent the gases.

Apr 16, 2007 | 06:10 PM

paschman2000

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Joined: Aug 2003

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Hey, i have a spare crankcase breather on the parts truck, i'll sell you, 5$ bucks, plus shipping and its yours! Jeff P.

Apr 16, 2007 | 09:45 PM

1954F250

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Joined: Jan 2005

Posts: 42

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From: Omaha, NE

The breather on the filler tube neck is the air inlet. The breather in the side of the block is the outlet. The theory is as you drive down the road, air blows past the tube that hangs down and creates a vacuum. The vacuum draws air into the filler tube and through the engine to remove vapors.