Hi Gray,
I too have never been able to resolve this discrepancy which seems to be
isolated to the numbers for the BJ8 engine only.
The way I read my Lucas manual it indicates that the 18 degrees of
distributor advance occurs at 3200 distributor RPM (6400 crank RPM) whereas
the earlier 6 cyl engine distributors reach max advance at 2000 RPM
distributor or (4000 crank).
My conclusion is that the BJ8 distributor has the potential to advance to 18
degrees (36 crank RPM) but this would only occur in extreme situations.
Any other theories would be most welcome. :-)
Michael Salter
100S (1955)
3000 Mk111(1965)
100 (1953)
AHX12 (1953)
Bugeye (1961)
http://www.netbug.net/blogmichael/
-----Original Message-----
From: owner-healeys@autox.team.net [mailto:owner-healeys@autox.team.net] On
Behalf Of Warthodson@aol.com
Sent: June 11, 2007 10:51 AM
To: healeys@autox.team.net
Subject: Ignition timing
I have ask this before but am still not clear on how to deal with the
apparent discrepancy.
The BJ8 distributor I have indicates 18 degrees (distributor degrees) of
mechanical advance. This is stamped inside. This equals 36 crankshaft
degrees. If
I add to this any static advance (10 degrees, per manual) and assume zero
vacuum advance I will be significantly over the 35 degree max. total advance
in
the shop manual. I have verified this is actually what is occurring by
checking
the max. advance with the vacuum advance disconnected, using a dial back to
zero timing light. (Several of our club member's cars are running 45 to 50+
degrees Max. advance.) I guess my question is: do I ignore the Max. advance
or
limit the Max. & accept what ever I get at idle?
A related issue is that when the advance is retarded to 35 degrees Max. it
is
difficult to get a smooth running idle.
What are your experiences?
Gary Hodson
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