[Tigers] Timing

[Smit, Theo]

Fuel permitting, on the street you can make your car a lot more responsive by running looser springs such that your timing does advance to the max as soon as practical. It may also be helpful to run more initial timing at idle, but then you have to make sure that your total timing doesn’t go further than you really want. Some distributors have adjustable timing stops; the factory distributors had two positions for the advance mechanism, that differed by two or four crank degrees. If those total advance amounts did not suit your application you would have to weld up and then regrind the advance slot.

Theo

From: Tigers <tigers-bounces at autox.team.net> on behalf of Tigers List <tigers at Autox.Team.Net>
Reply-To: Tom Witt <atwittsend at verizon.net>
Date: Tuesday, October 31, 2017 at 3:45 PM
To: Tigers List <tigers at Autox.Team.Net>
Subject: Re: [Tigers] Timing

A rambling mind:
I find it interesting that most performance articles refer to the “all in” timing in the 2,500-3,000 RPM range.  And when you consider most performance driving (racing for instance )one rarely would be under that limit, it makes a timing curve a somewhat mote point. It seems about the only advantage is getting the car started.

In the daily driving realm it does have its application. Unfortunately yesterday’s combustion chambers and today’s gasoline seem to be fighting one another. A knock sensor based timing curve does make sense.  From what I can see modern cars have a conservative timing curve and I’d think that is to protect the manufacture.  I use to have an Audi 5000 Turbo and for a mere $800 you could send the ECU off to be “re-programmed.”  My understanding was the  jump from 190HP to 240HP was primarily in the timing changes (premium fuel required). The fuel and boost changes were minor.  I saw a significant “snappiness” in my daily driver Mazda Protégé when I slotted the crank triggered reluctor wheel and snuck in an extra 4 degrees (still no pinging on regular gas).

So, timing can sure make power. The question is does the available gas, combustion chamber shape, quench, flame path etc. allow for that on the SBF head design(s)???

As Ron stated timing is an art form..., - that can be aided when computer generated “drawing” is involved. A mechanical advance system like the stock Tiger would seem to fall into “cave drawing” art.

From: Ron Fraser via Tigers<mailto:tigers at autox.team.net>
Sent: Monday, October 30, 2017 4:45 PM
To: tigers at Autox.Team.Net<mailto:tigers at Autox.Team.Net>
Subject: [Tigers] Timing

Here is a picture of the stock Ford primary distributor spring, on the left and secondary distributor spring on the right.

The primary spring should always have tension so the timing can always returns to its zero mechanical advance position.

The secondary spring has longer loops so it will not be part of the advance curve until higher rpms – the dog leg of the curve.   You can change the position the dog leg of the advance curve starts some by moving the spring’s tang position but changing springs maybe easier.

Timing requirements are different for every different engine configuration and operating condition.
Timing is kind of an art form and most of us are just rookies in this field, with some insights, just wanting our engines to run well.

Ron Fraser

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