> Date: Sun, 20 Aug 2006 11:48:56 -0400 > From: "Randy Geisel" <[EMAIL PROTECTED]> > Subject: Re: update on the 455 > > >'70 455, 10.25:1, 320 hp
The above info would be correct for a FACTORY configured engine, but if you remember what Neil posted previously: >Date: Sun, 20 Aug 2006 07:50:20 +0800 >From: "sharron&neil" <[EMAIL PROTECTED]> >Subject: RE: update on the 455 > >Oh and there is also a 20 stamped into the piston top which I presume means >20 thou over > >NEIL R STOKER >1969 OLDSMOBILE >DELTA 88 ROYALE This engine has apparently been rebuilt with .020" over pistons, so it is anyone's guess what the compression ratio, horsepower and torque are these days. Aftermarket pistons can be as much as .030" short on compression height and can have a variety of dish volumes, aftermarket head gaskets can be up to .022" thicker than factory head gaskets, and the piston-to-deck clearance can be larger than spec due to mass production tolerances. The CR can easily be as low as 7.5:1 depending upon parts and machine work. Kenneth 1971 Cutlass Supreme convertible Phoenix, AZ
