Load-a-matic Distributor Advance

[Anonymous]

Hey All,

I was trying to time my engine yesterday. I have a '66 I6 200 with a C5DF 12127 K Load-a-matic distributor. The advance on this distributor is solely vacuum as I understand.

After setting the initial timing and re-attaching the vacuum tube to the advance canister, I noticed that the timing was not changing, or was even slightly slightly retarding as I changed the throttle position. At 1300 RPM the timing was slightly less than it was at 600 RPM.

I went to Napa today and they found a new vacuum canister for me. It will be in first thing tomorrow. They said they didn't have a kit for new springs anymore.

The manual doesn't show much in the way of how the vacuum advance attaches to the distributor plate, and this is an area that I am not familiar with. Does anyone have any ideas what I need to look for or what my options are?

Can I change to a Dual Advance Distributor? How much would one cost ballpark and how hard is it to change? Would I see any improvement in performance? This car is my daily driver and I take a lot of road trips so getting good mileage is my main aim.

Thanks for any help yall can give.

-Dan in Atlanta

 

[cdherman]

First off, did you try putting some vacuum to the dizzy on your own. With a loadomatic dizzy, you should be able to generate enough vacuum with your mouth to advance it quite a bit.

If you are unable to advance it, then yes, try replacing the vaccum canister. I believe it has an arm that extended onto the plate of the dizzy and attached with a pin and split ring to fasten. At least my 240 loadomatic looks like that.

If you can advance it with manual "sucking" then don't replace the canister. You do have a loadomatic carb right? It does have a spark control valve etc.? A vacuum gauge would be my next suggestion, to make sure the carb is producing vacuum -- the loadomatic system is more complicated in terms of the internal channels in the carb. If something is gunked up, you may be getting no vacuum at all. No vacuum at all would mean either a carb rebuild or a more extensive upgrade (like Carter YF, or Autolite 1101, with a duraspark or "thermactor" dizzy).

good luck

 

[Anonymous]

Hi Dan,

Sounds like either 1 or two things:

1) You don't have the matching carb "Autolite 1100" with a spark control valve. I had this problem on my '68 for the longest time because I never realized the previous owner removed the stock dual advance distributor and replaced it with a load-o-matic.....

or

2) You have the vacuum for your distributor attached to direct manifold vacuum and not the spark control valve vacuum port.

If #1 is true, then yes, upgrade to a vacuum and centrifigal advance distributor (look at doing a Duraspark II upgrade).

Bascially, what is happening is that you are getting full advance at idle because that is where you have the most vacuum. When you rev it up, you loose vacuum causing the timing to retard, and you don't have any centrifugal advance built into the distributor to make up for it.

 

[Anonymous]

Thanks for the help from the two who replied. Today I tried applying mouth vacuum to the distributor and it seemed to advance sloghtly and retard slightly when I blew/sucked. I checked the vacuum from the carb and there was definitely vacuum present as the speed advanced. Then I got confused.

So i went to Napa and bought the new vacuum modulator for the distributor and figured I'd install it to see what happened. When I got the old modulator off i could suck right through it and all my sucking barely changed the position of the arm. I replaced the old canister with a new one and it seems to be working well now.

Thanks for all the help.

-Dan in Atlanta