Steve,
>>>While a change in springs can influence the rate of mechanical advance,
the total advance is controlled by the weight slot stops.<<<
Yes, that is true, and part of the "potential" problem. I will try and
illustrate (values are hypothetical):
Stock springs:
Initial advance 10 degrees
Centrifugal advance (at crank) 26 degrees
Total Advance 36 degrees
Softer springs (with distributor NOT moved from previous settings):
Initial advance becomes 14 degrees (extra 4 degrees come from the weaker
springs allowing the weight to add centrifugal timing advance - even at
idle)
Centrifugal advance (at crank) 26 degrees
Total Advance 36 degrees (which is where I think your logic is leading you)
BUT, if the advance was desired to be reset back to the Initial 10 degrees,
the Total would then become 32 degrees. In essence the weaker springs use 4
degrees of the previously available 26 degrees. Thus, the slot only
"effectively" provides 22 degrees. So, if it was desired to add softer
springs, but correct the initial advance back to it's original setting the
(I'll say potential) Total timing could be compromised. Potential - in that
some softer springs might not create the problem, but others, given how soft
the springs are and/or how heavy the weights are, can at times create the
issues I have presented. At least I have experienced it. Granted I do not
purchase application specific springs, but grab what I've got and "tinker."
Tinker - which typically involves spending a whole day and often ultimately
deciding I should have left well enough alone! :-(
Tom
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