On Thu, 7 Jan 1999 19:47:35 -0000 "Paul Hunt" <paul.hunt1@virgin.net>
writes:
>There are two types of vacuum advance - what might loosely be called
>'British' advance and 'North American' advance.
>
>The Britsh advance is non-existant at idle, maximum under cruising rpm
>at
>low throttle openings, and negligible at high throttle openings.
>
>The NA advance is maximum at idle, otherwise it is much the same as
>British
>advance.
>
>British vacuum is taken off the carb right by a throttle disc, NA
>vacuum is
>taken off the inlet manifold.
>
>Even so, British tuning instructions also state that the vacuum line
>should
>be removed and plugged for setting dynamic timing even though the
>vacuum at
>tuning rpm is negligble.
>
>PaulH.
Hmmm.
I guess that means both my MG's aren't British.
Both have the vacuum port on the manifold and both have max vacuum(read
advance) at Idle
Funny, I could have sworn that the BMHIT certificates said they came
from England.
Rick Morrison
72 MGBGT
74 Midget
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