Crankcase Breathers |
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Crankcase Breathers |
McMark |
Sep 12 2017, 04:58 PM
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#41
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914 Freak! Group: Retired Admin Posts: 20,179 Joined: 13-March 03 From: Grand Rapids, MI Member No.: 419 Region Association: None |
I was looking at the factory manuals and talking with someone about crankcase breathers. We were talking about breather setups for carbs specifically. And I realized as I was looking at the breather diagram that it appears that the breather ports on the heads were included to supply extra air to flow through the engine case. And then I read this little snipped in the manuals which seems to support my thought:
QUOTE Crankcase ventilation has been considerably improved in the engine by ducting fresh air from the air filter. This modification reduces crankcase condensation and icing at low outside temperatures. So following that logic... If the crankcase breather (at the oil filler neck) isn't connected to a vacuum source, then the ports at the heads should/could be plugged instead of connected to a breather box. Thoughts? Contradictions? Agreement? I realize people have been connecting breathers all sorts of different ways and most work just fine. I'm more interested in the theory aspect, and refining an 'ideal' installation since we already know many ways to 'make it work'. Attached image(s) |
gothspeed |
Jan 1 2018, 10:42 AM
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#42
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Senior Member Group: Members Posts: 1,539 Joined: 3-February 09 From: SoCal Member No.: 10,019 Region Association: None |
Do type 4 engines use a negative crankcase ventilation check valve?
Also if the cylinder head vent tubes are capped does air pressure build in there and counteract oil pressure through the push rods and the rockers? which may be a good thing, IF oil levels in valve the covers are too high and do not drain fast enough into the case? |
ChrisFoley |
Jan 5 2018, 07:50 AM
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#43
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I am Tangerine Racing Group: Members Posts: 7,934 Joined: 29-January 03 From: Bolton, CT Member No.: 209 Region Association: None |
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gothspeed |
Jan 5 2018, 02:46 PM
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#44
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Senior Member Group: Members Posts: 1,539 Joined: 3-February 09 From: SoCal Member No.: 10,019 Region Association: None |
Do type 4 engines use a negative crankcase ventilation check valve? Stock D-jet engines use a PCV valve. If that fitting on the oil tower box is used for a vent hose the guts need to be removed first. Cool, thank you for the response (IMG:style_emoticons/default/smile.gif) |
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