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Old 01-01-2020, 07:47 PM   #2005 (permalink)
phunk
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Join Date: Mar 2009
Location: Chicago
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Quote:
Originally Posted by TopgunZ View Post
How was your guys piston slap? Mine sounds like a damn diesel, not only on start up, but all the time.

Do you consume oil?
If you used a stock bore piston, that can be sort of typical. They will often arrive too small to meet recommended piston to wall clearance for their alloy. I learned the hard way with that on the first VQ build I ever did for a customer. I had never used stock bore pistons before, but he supplied some he purchased online. My machinist who was setting up the clearances told me they came in on the loose side but that it would be OK, so I proceeded. On first start-up I heard it immediately. I couldn't return a car sounding like that. A day or two later I tore it all back down and rebuilt the engine again out of pocket. Changed the piston setup so we could achieve proper piston to wall clearance. Sounded great and the car went on to live happily ever after.

With correct piston to wall clearance, you shouldn't notice much (sometimes depending on exact alloy used), if any, more piston slap. Perhaps on a real cold start.
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