In a message dated 31/07/00 2:48:14 PM Pacific Daylight Time,
owner-mgs-digest@autox.team.net writes:
> There is one advantage to going to the lower (8.0:1) compression dished
> pistons versus the higher (8.8:1) flat tops: A lot of performance
> enhancements (cross flow head, Hans' supercharger) require the lower
> compression in order to run the motor on 92 Octane gas.
A couple of comments here. On an MGB (we are talking 'B' here, aren't we?),
the flat top pistons give you more than 8.8 compression.
Second, while you are correct that any form of supercharging or turbocharging
works well with a lower compression ratio, you are incorrect in attributing
that same phenomenon to crossflow heads.
In fact, the crossflow heads are alloy and can dissipate heat better than a
cast iron head. They actually call for _more_, not less compression to
function properly, and with the lack of hot spots will work well with 92
octane gas. I have run 10.5 compression on 94 octane with no trouble. I don't
imagine that flat top pistons and an alloy head would be any problem with 92
octane.
Bill S.
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