Chris Delling wrote:
> Looking for some subjective opinions here. I am sure that all would
> agree that an increase in compression ratio will yield an increase in
> H.P. output.
Yep ... ;^)
> My question regards bang for the buck. Given an engine with an
> 8.0 to 1 compression ratio, vs. the same engine with a 9.0 to 1 ratio,
> what % of increase would be expected. I am laying out my plans (and
> budget) for my winter project, namely extracting more from a stock 77
> B mill (sans emissions, add Weber DGV). Trying to weigh the relative
> gain to be had by swapping to higher comp. pistons vs. stock (without
> any other mods, for comparison sake). I have confidence that many
> have opinions, and potentially similar experience, so please pass along
> your ideas.
Hmmm ... "without any other mods" ... that makes it a bit more difficult. ;^)
The 'Home Market' engine produced 84bhp(DIN) versus the 65bhp(DIN)
produced by the 'North American' engine ... so a substantial increase can
be had by coverting to the 'Home Market' specification. To my knowledge
the 'Home Market' specification was sans emissions, 9.0:1CR, SU carbs,
LCB exhaust, and a different dizzy curve, but I am sure that the enthusiasts
"across the pond" can provide a more accurate description.
As you can see, with the exception of the dizzy, the 'Home Market'
specification is pretty close to the '9.0:1CR, sans emissions, add Weber'
specification that you outlined.
IMHO ... once you have returned the engine to its original specification ('Home
Market'), then your biggest bang for the buck would be a 'modified' cylinder
head followed by a 'fast road' cam (see: 'Peter Burgess' Book).
Hope this helps ...
Safety Fast! ... larry.g.unger@lmco.com
'61 MGA 1600 MkII - with stock 8.9:1CR
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