Well, it looks like you absolutely know how to make a lucas distributor
work. My tolerance is far less than yours.
The distributor I tried to use is the 45D. What finally put me over the edge
is the realization that in this "racing" distributor the point plate is the
same as the vaccum advance unit and is "fixed" in place with a tab that lets
it shake about two degrees. Yes, I could fix that, and I could probably
properly index the distributor with a distributor machine, or I could buy a
Mallory and start building a catapult.
-----Original Message-----
From: Fubog1@aol.com
To: Bill Babcock
Cc: fot@autox.team.net
Sent: 6/3/2005 4:37 AM
Subject: Re: Mallory dual point dizzy now Lucas slam
Basically the early Lucas units, up to the late 60s, had a symetrical
cam lobe & a tendency to bounce the points at medium-high rpm, with the
standard points. There are/were different points available with more
spring tension, or you can add a spring strip, to raise the limit using
this unit. The later assymetrical lobe design has a ramp that opens them
quicker & increases the coil saturation time, allowing a more reliable
spark at high speed. Then they came out with the 45D unit which was
designed for the HEI system. It has the larger body, cap & rotor, & the
cap has walls inside, all designed to prevent spark-scatter from the
HEI.
A point type distributor based on the 45D body, assymetrical cam, good
points with a locked braker plate, is good for over 7000 rpm in a 4
cylinder, reliably. (example- my girlfriends POS 1275 Sprite will pull
reliably to 8k). For max reliability or regular use over 7000, I
normally will fit an optical trigger unit such as Allison or Lumenition.
6 cylinder engines are a different story since the saturation time is
obviously decreased by having 6 impulses per distributor rev vs 4. Dual
point systems were really designed for 8 cylinder engines, where there
is absolute minimal saturation time.
It goes without saying that the distributor has to be in good shape re
shaft, bushings, breaker plate, etc & a critical point is the indexing
of the breaker plate to the body. If it's not locked in the correct
orientation, the rotor tip won't line up with the contact in the cap.
You can see where the spark is going by looking at the carbon track on
the tip of the rotor.
Safety FasTR,
Glen
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