O/T Compression ratio and supercharging

[SPECTRO COATING CORP.]

-----Original Message-----
From: Don.F.Broadus at ucm.com <Don.F.Broadus at ucm.com>
To: diy_efi at efi332.eng.ohio-state.edu <diy_efi at efi332.eng.ohio-state.edu>
Date: Wednesday, May 26, 1999 4:08 PM
Subject: RE: O/T Compression ratio and supercharging


>You are correct, The mechanical compression ratio can be 10:1 but when you
>check it with a gauge the effective compression ratio
>pressure will  be on par with a 9:1 engine. Mechanical compression gives
you
>efficiency while effective compression ratio that is controlled by valve
>timing gives you knock control and good combustion.


Kinda explains the 18:1 compression ratios used in all out racing engines,
Doesn't it?