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Registered User
Join Date: Feb 2014
Posts: 6
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2.7 refresh upper engine: smoke after running 5 minutes
I have a 1974 Porsche 911 that is heavily smoking after running for 5 minutes. I have been told by experienced people that I should start with an upper engine refresh. I was wondering what an upper refresh exactly involves? What tools are needed and what parts are needed. I see a couple of workshop books for sale . I was thinking of buying the Hayes workshop manual.
Would like to put together a parts list. I am doing this job myself in my own garage. Any suggestions of helpful step-by-step instructions would be greatly appreciated!! 
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09-22-2019, 05:08 AM
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The 9 Store
Join Date: Dec 2009
Location: Wilmington, DE
Posts: 5,318
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First do a leakdown test and check head studs and oil level. Oil has to be checked when engine is running and at operating temp. It could just be overfilled.
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All used parts sold as is. Last edited by mepstein; 09-22-2019 at 07:07 AM.. |
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09-22-2019, 07:05 AM
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Registered
Join Date: Oct 2008
Location: Nash County, NC.
Posts: 8,467
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Doing a 2.7 top end is doing the whole motor
The mention of studs, Mark points out is the important corner of the repair. The studs are steel in the magnesium and the cylinders are aluminum pulling against the magnesium. Your blessing is your a 74 and the studs may not be pulling but, you don’t know until you torque your build. If you build and pull a stud the motor has to completely torn down because drilling and tapping 24 stud holes leaves lots of mag. Debris everywhere and it’s got to be cleaned. Bruce |
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09-22-2019, 11:44 AM
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It's a 914 ...
Join Date: Jan 2008
Location: Ossining, NY
Posts: 4,690
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Give it a little more time running before deciding on a rebuild. It might need work, or as suggested be overfilled with oil. It’s even possible that from sitting that oil pooled in the engine from the tank. It can get into the cylinders when this happens, and smoke like a mother until it burns off. It can take a good 5-10 minutes running for that to burn off, if that’s what’s happened.
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09-23-2019, 05:49 AM
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Registered
Join Date: Apr 2007
Location: wisconsin
Posts: 2,553
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How many miles on the motor? Sounds like your valve guides are worn, leak oil into the exhaust, and when it gets to a certain temp, starts to burn off...
Expensive to fix... |
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09-23-2019, 05:57 AM
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Registered
Join Date: Jan 2011
Location: Gulf Coast FL
Posts: 1,484
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Couple of other possibilities;
exhaust system and muffler interior could be saturated with with oil and it starts to burn off after 5 minutes mixture could be very lean, a richer mixture may stop the smoke |
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09-24-2019, 03:16 PM
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