buick-rover-v8
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Re: FW: Compression Ratio on V8

To: Pieter Erasmus <PieterE@liw.denel.co.za>
Subject: Re: FW: Compression Ratio on V8
From: Ted Schumacher <tedtsimx@q1.net>
Date: Thu, 13 Jan 2000 15:07:26 -0500
real world terms you normally recieve approximately 15% return for every
positive change made to a base engien.  cam manufacturers, manifold makers, etc.
may claim more but it you stick with the 10% rule, you will find it's pretty
realistic.  if you want an inexpensive but accurate method f measuring
horsepwoer, run the car through a quarter mile (drag strip)  HP =  (trap speed
in mph divided by 234)(cubed) divided by weight of vehicle.  you will lfind this
is accurate within about 4 - 5%. ted

Pieter Erasmus wrote:

> > Compression Ratio on V8
> >
> > How much power increase can I expect if I change the standard 8.13:1 CR
> > pistons in my 3.5 '80 RR (with twin Strombergs) to 020" 9.75:1 CR pistons,
> > assuming everything else on the engine stay the same. I allready have
> > fitted a lumenition ignition, mild Piper cam, twin downpipe exhaust
> > manifolds from a '95 Disco and free-flow exhaust.?
> >
> > As a matter of interest, I peeked under the bonnet of a 4.0l series ii
> > Disco, and gues what, 8.25:1 CR pistons fitted. Why is LR using such low
> > compression ratios?
> >
> > Regards
> > Pieter Erasmus
> >




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