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Registered User 4'10
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Pitting on back side of intake valves
Is pitting on the back side of some of my intake valves an issue? 3 of the 6 intakes have small pits in them, the other 3 (as well as all 6 of the exhausts) are nice and smooth. Faces are fine also. The engine has sat unused for the past 28 years and I just recently got the valves out and cleaned. I've no idea if the pitting was there before I lost the rod bearing or not...
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jt - '69 911E, PCA-RMR '75-'82; Current Other: '16 BMW 328i, '18 Subaru Forester, '09 Kawi Concours 14, '85 VW Westfalia, C172, C152; Previous Notables: '89 Goldwing (RIP), '80 Suzuki 850, '64 Ducati 250, '64 Bug (wish I'd known about that #3 exhaust valve...), '59 Austin-Healey BN100-6, '59 Impala 2-door hard-top (cool!). '49 Cushman motor scooter, Grumman AA5A & AA5B |
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09-23-2013, 02:41 PM
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Could be some corrosion from sitting has damaged the machined surfaces. Fuel additives, water and time ate some surface metal away. Why only three..maybe those were open..closed..or on the same side of the engine, became exposed and got damp while sitting.
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09-23-2013, 03:21 PM
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Registered
Join Date: Apr 2009
Location: Cape Vincent, NY
Posts: 841
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Seen pitting on intakes in lots of engines, never known it to be indicative of a problem.
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1968 911S "Leona" Air goes in and out, blood goes round and round, any variation on this is a bad thing. |
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09-23-2013, 03:26 PM
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Join Date: Jul 2001
Location: Portland Oregon
Posts: 7,007
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As the others have written, its simply due to corrosion and not a problem unless it occurs on the seats.
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Steve Weiner Rennsport Systems Portland Oregon (503) 244-0990 porsche@rennsportsystems.com www.rennsportsystems.com |
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09-23-2013, 05:31 PM
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Registered User 4'10
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Okay. Thanks guys.
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jt - '69 911E, PCA-RMR '75-'82; Current Other: '16 BMW 328i, '18 Subaru Forester, '09 Kawi Concours 14, '85 VW Westfalia, C172, C152; Previous Notables: '89 Goldwing (RIP), '80 Suzuki 850, '64 Ducati 250, '64 Bug (wish I'd known about that #3 exhaust valve...), '59 Austin-Healey BN100-6, '59 Impala 2-door hard-top (cool!). '49 Cushman motor scooter, Grumman AA5A & AA5B |
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09-23-2013, 09:29 PM
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1986 Porsche 911
The Yellow Flyer
Laverda 1000
Silver Arrow
Jaws
