[Tigers] Timing

[Ron Fraser]

Tom
	It's not all that hard.   The weights generate a force with RPM;
that is why the primary spring must have some tension so the distributor
always returns to base timing position.   The force of the weights act on
the primary spring 1st and then the secondary spring at higher RPM.  The cam
action as you call it is just a smoother way to translate the force of the
weights to degrees of advance.

	36 MPG seems really good for just mechanical advance - you need to
see what the advance curve was for that distributor.   I would think at
least 45 degrees advance would be needed to get that MPG.

Ron Fraser

-----Original Message-----
From: Tigers [mailto:tigers-bounces at autox.team.net] On Behalf Of Tom Witt
via Tigers
Sent: Saturday, November 04, 2017 8:52 PM
To: tigers at autox.team.net
Subject: Re: [Tigers] Timing

Thanks for the pictures Ron.  The second type seems to use not only the
springs, but the cam action on the weights edge as a means of plotting the
advance curve.  The math for the RPM, spring tension, weight... - AND cam
action baffles my brain.  Somewhere I have a Mallory dual point (no vacuum
advance) distributor. Got it in a pile of "free" stuff at a Mopar swapmeet
(No step child parts for him!).  I'll have to check it's advance system out
some time.

Oddly I had a Volvo 544 that got 36 MPG on the highway and it only had a
mechanical advance (no vacuum). Seems to defy the necessity of vacuum
advance with mileage like that.

-----Original Message-----
From: Ron Fraser via Tigers
Sent: Saturday, November 04, 2017 12:16 PM
To: 'Gary Winblad' ; tigers at autox.team.net
Subject: Re: [Tigers] Timing

Picture 1 is the early style Ford distributor with oil port, ID# C2OF-J -
note there is 1 slot size for each weight - this is the area that I have
seen wear problems

Picture 2 is the later style Ford distributor, ID# C8AF-E - note the 13L &
18L slots - the 13L slot is being used in this example

Just wanted to show the differences in these 2 mechanical advance systems

Ron Fraser

-----Original Message-----
From: Tigers [mailto:tigers-bounces at autox.team.net] On Behalf Of Gary
Winblad via Tigers
Sent: Friday, November 03, 2017 10:58 AM
To: Smit, Theo <Theo.Smit at garmin.com>; Tom Witt <atwittsend at verizon.net>;
tigers at Autox.Team.Net
Subject: Re: [Tigers] Timing

The Tiger distributor I bought from Sunbeam Specialties(was years ago) was
the kind with the two position advance limit.  I just had to turn it to the
more limited stop, put in lighter speed shop springs and then limit the
vacuum advance. All on my stock 260, works great, still on regular gas.
Gary 


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