Posted by: porschebahn | December 10, 2008

Part 1 of 1993 Porsche RS America Engine Rebuild

Do not trust just anyone to rebuild your engine.  This one is from a ’93 RS America that was built for the track.  The owner had just spent $25,000 for the rebuild and modifications.  He had an over rev while down shifting in a race and broke some rocker arms. 

He brought the car to George for repair and George discovered the valve springs were not set up properly.  They went into premature coil bind which caused the rocker arms to brake.  When George tore the engine down to check it out as requested by the owner he found several other mistakes. 

 They had used silicone to seal the case halves instead of the proper flange sealer.  George found excess silicone floating around in the case.  They had not torqued the case in the proper sequence which combined with using silicone as a sealer caused internal oil leaks.  Notice the premature bearing wear.  They reused the old crush rings, which are basically the head gasket, another no-no which caused compression leaks.  The pistons were fly cut for valve clearance.  There is not enough material in the stock pistons for this modification, you replace them with the proper piston.  The cams were incorrectly timed as well.  Look at the silicone on the old exhaust gaskets instead of replacing them and you can see silicone in the grove around the exhaust ports.  The connecting rods are not correct either.  The owner paid enough for a proper build but as you can see did not get it.

When choosing an engine builder, get references! Not everyone has the expertise to work on them.

I will post more as the build goes along.

* Part 2 update please visit: https://porschebahn.wordpress.com/2008/12/24/update-of-1993-porsche-rs-america-engine-rebuild/

* Part 3 update please visit: https://porschebahn.wordpress.com/2009/01/03/part-3-of-1993-porsche-rs-america-engine-rebuild/


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