Adjusting initial advance with a 3 bolt helmet dist....

[Blownflatheaddeuce]

How is this done guys? These dissys are newer to me than the 8BA type.

Id like to try a little more initial timing to sharpen up the throttle response after a cam change.

Can a few more degrees initial timing be added?

Thx

BFD

[Bruce Lancaster]

The bolt on the side with a graduated plate under it is the adjuster. Distributor turns CCW when viewed from the front, moving bolt CY would advance, CCW would retard.
I've posted the secret instructions on establishing a starting point (spec is 4 degreees) but centerline is real close.
Investigate having brake backed all the way off, then back down just a little to maintain stability, and see what advance curve you have as marked on rear of shaft. The 11a 1941 curve is quicker than the common 68 and will help.

[Blownflatheaddeuce]

Hi Bruce thanks for that, do you have any pics of what you are describing?

[Bruce Lancaster]

look in figure 3, part 42 is the bolt securing timing adjustment. Move in accordance with rotation as described above...I don't want to say up or down because the timing plates appear on different sides of the various distributors, I think, and i can't remember the early positions.

[Kahuna]

First, check the distributor: On the shaft that is cam driven, there will be numbers/letters:
Most all will have 11A or 68. This will determine the advance curve you have: If there are no identifying marks, then you will have to look at the advance weights inside the dist.
11A -0 degrees @ 400 Rpm---22 degrees @ 1200 Rpm (Engine Rpm)
68 -0 degrees @400 Rpm---16 degrees @ 1900 Rpm (Engine rpm)
Knowing this may assist you in being able to increase the initial advance without exceeding the total advance you may want.
It's real difficult, I think, to alter a Helmet type advance, but by using a combination of parts you can achieve a good result

[Blownflatheaddeuce]

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Thanks fellas I'll give it a go and see what happens.

[Ol' Ron]

You can also grind the slots in the advance wheel. Not sure how much per deg of advance. Done on a distributor machine would do it. However this method will depend on the Vac adv to limit the adv in acceleration. I haven't tried this, YET! however it's on my bucket list.

[AnthonyG]

Bruce are the illustration figures from a Motors Manual? I see a 1934 date is that the manual date?

[FlatheadTed]

The last one I did was advanced 10 Deg he had the vacuum screwed right in ,This would hold it in the retard position longer .He said it ran better that way , I can see why ,You can play with your advance plate until you hit the sweet spot .sort of trial and error approach .

[Blownflatheaddeuce]

Interesting - so from the stock 4 deg setting - how much more intitial advance can be added without modding the adv plate and just by adjusting the aforementioned screw/bolt.

Another 2 degrees perhaps?

[BUBBAS IGNITION]

Originally Posted by Blownflatheaddeuce

Interesting - so from the stock 4 deg setting - how much more intitial advance can be added without modding the adv plate and just by adjusting the aforementioned screw/bolt.

Another 2 degrees perhaps?

The machined slot is usually 12 degrees , 6 up and 6 down. So the adjustment would allow 6 degrees of advance, assuming the break set of points is perfect at 27 degrees of dwell. For each degree of dwell on break set of contacts timing changes 2 degrees as well.

[Blownflatheaddeuce]

Great info guys....what would one full clockwise turn of this adjustment bolt constitute in degrees ?

[BUBBAS IGNITION]

Ford specs were turn srcew out until engine pings/spark knocks and turn in until it stops on accelleration...

[Hoop]

"The machined slot is usually 12 degrees , 6 up and 6 down. So the adjustment would allow 6 degrees of advance, assuming the break set of points is perfect at 27 degrees of dwell."

Bubba did not tell you that he was talking about "distributor" degrees, not crankshaft degrees. Since most folks are interested in degrees of crankshaft advance, the scene changes a little.

Also, I can't tell which distributor "Blown" is working with, but 27 degrees of dwell is a very early spec ... 22 1/2 for later distributors with separate points.

So, what is the max advance for a 11A distributor? (Note that 11A is 11 degrees of distributor Advance ... x2 = 22 at the crank.)

How much advance are you figuring you're going to need?

[Blownflatheaddeuce]

Not sure as yet Hoop, yes Im are of the diff b/w crank v dist degrees.

I guess I can creep up up on the advance, test and adjust accordingly. Adding some cyl pressure should help in the TQ dept with the cam swap.

Should be interesting.....

[Bruce Lancaster]

That pic is from a Ford patent covering some distributor details AND a simple static timing adjustment plate (identical in concept to aftermarket 1930's pieces) that was to be welded to the firewalls of Fords as standard equipment! The electrical arrangements for that have some very clever bits.
Bulletins show 11A as having 22 degrees crank maximum versus 16 for the 68 mechanism. I think the big factor is that the 11 starts advancing at a lower RPM, right off idle, which I believe flatheads like.

[FlatheadTed]

We Ran rental cars (Jap ) for a few years and the first thing I would do when commissioning a fresh car was roll the distributor forward about 1/4 (adv ) then road test it ( no strobe ) .this would often turn the car from a asthmatic machine into something that was real lively .Ted

[Bruce Lancaster]

"Great info guys....what would one full clockwise turn of this adjustment bolt constitute in degrees ?"
Not sure what you are asking here...if this is about the vac adjustment, it does not change degrees of anything really, it puts a drag on the activities of the advance mechanism as it is tightened so that advance happens more slowly to cure spark knock. On modern gas you probably want it ALMOST all the way out.
The screw on graduated plate loosens the breaker plate and allows you to advance or retard static setting and so to move whole curve starting point.

[Hoop]

Nice to see that you can count on Ted, Bruce and Bubba (now, Kahuna) to help out when distributor beginners have questions. Bubba generously gives advice even though he does distributors for a business.

Too often early flathead distributors are presented as being mysterious or too difficult to work on ... often by folks who themselves have not spent the time to learn about them and are just repeating old myths.

For the sake of the hobby, one of the best ways to really understand a helmet or a crab is to start with a manual device, like the K R Wilson or a Wasco.

(Something Bubba mentioned above has sent me back to do some tinkering. It'll start with the KRW fixture then go to the Sun machine ... maybe the distributor geeks can have a get together ... I vote for New Zealand.)