RBL Alfa Sprint
  
  Joined: 30 Mar 2003 Posts: 162 Location: Leicestershire
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				 Posted: Sun Mar 22, 2009 8:47 pm    Post subject: Compression Ratio | 
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				I'm building a new 1.7 8v engine. As part of the improvements i'm increasing the CR and doing some of the mods on the alfaboxertuning site.
 
 
I've measured the current compression ratio as 9.3/1 and want to raise it to 10/1. From my calculations, this would mean skimming 0.7mm off the block face.
 
 
Here are the measurements:
 
stoke & bore: 71.8 x 87mm
 
combuston chamber: 20.2cl
 
piston crown dish: 22cl
 
gasket thickness: 1.3mm
 
gasket bore diameter: 88mm
 
piston to deck:0.2mm
 
 
I haven't measured the valve / piston gap at TDC with everything bolted together and timed up, but the measurements I have done seem to indicate there'll be 3mm gap at TDC.  Is there anywhere I can find valve open and closing times in comparison to TDC for a standard cam?
 
 
Any advise/sugestions would be welcome
 
Rich _________________ Porsche 550 spyder replica with Alfa Sprint 1.7 engine | 
			 
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