Distributor Cam Lobes. Number 3 Slightly retarded. True?

[Teafortwo]

I seem to remember reading that number 3 cylinder distributor cam was slightly retarded. That is to say not exactly at 90 degrees between the other lobes? I think the idea was to slightly retard the firing of number 3 cylinder so that it might run cooler to protect the number 3 exhaust valves and prevent valve stem failure.
I question this as I think it desirable that the output of each cylinder be equal and balanced.

So is it myth, fact or fiction, or the ramblings of an older man?

[williamM]

true- pre dog house oil cooler.
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[airschooled]

It's true on some distributors. I do not know which, but I would wager than it would be any distributor from the vacuum only era (205M/T) and those prior. I'll check my 205Ts this week...

I have seen aftermarket 009s with it, and without it. I have also seen aftermarket 009s with all four cylinders being off a few degrees from each other. Mallory distributors have the most consistent timing between cylinders, though mine wore out quicker than I would have liked.

Robbie
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[tasb]

The following Bosch distributors do have a retarded no. 3 lobe:

113 905 205 K

13 905 205

113 905 205 M

113 905 205 T

and there were a few others- oddballs. Type III's I have not tested but theory would say no on the retarded no. 3 since the cooler was not in the way of air flow.

for the reasons stated above. I would call the adaptation miniscule in reality.
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