OK, I realized that my questions probably occur more offen with the 67-73 series than with mine, so I though I'd post it here. Hope you guys can help!

I have a 1965 F-100 with a 240 six. It has an Autolite 1101 carb with one vacuum line to the dizzy. I want to replace/upgrade the dizzy to a vacuum/mechanical unit. The current distributor is a vacuum only unit, so far as I know. Unless I am really an idiot, I do not have a thermactor pump.

I have been told that a single vac unit for a 1973 will be a mechanical and vacuum advance unit. Part # 302610

When I look up the various options at rockauto and Napaonline, I get the following part numbers and descriptions (all are points type):

Rockauto 1965 w/o thermactor cardone #302609
Rockauto 1965 with thermactor cardone #302610
Napa 1965 w/o thermactor NAPA #NRD482609
Napa 1965 with thermactor NAPA #NRD482610

Rockauto 1973 with single vac advance cardone #302610
Rockauto 1973 with dual vac advance cardone #302689
Napa 1973 with single vac advance NAPA # NRD482610
Napa 1973 with dual vac advance NAPA # NRD482689

As you can see, there are three distributors that seem to be out there. Basic type, 2609, from 59-67, is a single vacuum hookup, vacuum advance only dizzy. It has a shaft that is “D” shaped. Second, 2610 (65’-69’), appears that a single vacuum plus mechanical advance distributor which is also a “thermactor” type distributor. It has a “C” shapped shaft, with a slot as well as a flat spot. Finally, the last points type dizzy before duraspark, was 2689 (1970-74). It has two vacuum hookups (“dual vacuum”) and a “C” shaped shaft. Or am I not understanding something? The Pertronix catalog helped me with the shape of the shaft and years.

Can I use a thermactor (2610) dizzy with my 240 and autolite 1101? Apparently, a thermactor dizzy and dual vac advance are NOT the same thing, right? I don’t have anything to hook the dual vac dizzy to, so I want to avoid it.

Hope this gets a response.

Thanks…

 

O.K. to begin with this go to this link and study it alittle

http://www.fordmuscle.com/archives/2...ng/index.shtml

From the little bit I know I'll try to help. It's my understanding that all distributors are mechanically advanced, most are mechanically advance with a vacuum advance set-up also. The weights for the mech. are on the inside underneath the breaker plate. if it has a vacuum line too it it is also vacuum advanced. This is used for part throttle aceleration and fuel economy. Read the link and it should help you sort out what you have and also how to set up what you have.
Clint

 

Your distrubutor has both a mechanical and vacuum advance. The weights and springs are under the breaker plate. Why do you think the dist needs to be upgraded, is there a engine performance problem? What are the symptoms? If you have a timing light you can verify the operation of both the mechanical and vacuuum advance.

jwrboss302

72 F250 CS

 

OK, over on the Fordsix forum, I have read and been told that some distributors were vacuum advance ONLY.

It is possible that the forum members were wrong. It is also possible that they were right, but that my 65 has a dual vac/mech advance.

I definitely want to have a mechanical advance. And I definitely want to have the right distributor BEFORE I plunk down the money for a Pertronix Ignitor II setup, because there are two models for old I6 240 and 300 engines. Id hate to have the wrong Ignitor later when I discover that I don't have a mech advance.

So I suppose I should pull the dizzy or dissasemble it and just find out for myself.

Later........

 

The guys at the Fordsix forum are correct, for '65 all the 240 engines came with a vacuum-only advance called a Loadomatic. If you give me the number off your dizzy I can look it up and tell you. Look where it says 12127, need to know what's before it and what's after it. For example, here's one for a manual trans C5AF-12127-AD.

Whatever it is, you should really run a dual advance unit as the Loadomatic fairly sucked, the timing was not that consistant. In '66 most of the 240 engines got the dual advance that came on the 300.

Barry

 

I found a stack of new dual diaphram 240 distributors in an army surplus store for $15 each. I put one in my 68 240 and just didn't hook up the inner vacuum chamber. I ran all the timing with my dial back light and it seems to work within the factory specs. I think I did adjust the vac. advance just a little to fine tune it. I changed my 72 300 over to a duraspark years ago and have been very happy with that setup.

 

Thank you Barry! Sounds like you are pretty sure about that. The loadomatic works with a throttle body vac advance that came out of my Autolite 1101 carb -- at least I have read and heard that before too.

The pickup is setting in pieces at the body shop currently, so I cannot give you the dizzy #, but I will FOR SURE! Tomorrow or Monday.

Thanks again!!!!

 

I now know so much about my dizzy and carb that I don't know anything........

I (this is brilliant) realized that I have the shop manuals for the pickup, and, suprise, they are useful. So I finally read the carb and dizzy sections.

I DO have a Ford "Loadomatic" distributer. This has NO mechanical advance. I took it apart today. These distributers were on the big 240/300's only one year, 1965. In 1966 they switched to the vacuum and mechanical dual advance dizzys. (Not to be confused with a dual vacuum input vacuum advance, which was later, in the 70's)

I have either an Autolite 1100 or 1101 carburator. The Loadomatic system, at least in the early days, supplied a mixture of manifold (via throttle body) vaccum, as well as venturi vacuum via a small valved passageway to the main venturi. This was done to overcome the problem of LOW manifold vacuum, and subsequent inadequate advance during certain situations (running under load, WOT etc.).

The autolite 1100 or 1101 had a valve that shut off the manifold vacuum when it got lower than the venturi vacuum. This is the so-called "spark control valve".

Now for the kicker, and the reason that I said I now know nothing.

Sometime later, ford changed the 1100/1101 carbs and removed the spark control feature. The lower carb body casting looks the same, but the location of the former spark control valve is no longer threaded and is basically a blind end hole.

I supposedly have an original carb, BUT mine has no spark control valve, and no threads in the casting. So I have only manifold vacuum as far as I can tell, maybe.

I may have only "half" of Ford's loadomatic setup. And I have no clue if I can safely assume that the dual dizzy that the 240 used later is OK, or if I will have problems. The reason I worry about problems has to do with the following information I got off fordsix:

"(the distributor) has to match the carb. Put a vacuum gauge on the distributor connection and rev the engine past 1000 RPM. It will either go to 5 to 7 inches, or to 16 to 19. Low reading is a Loadomatic carb. High reading is dual advance." -- Jay in CA

If I knew for sure that I have a later carb, with "high vacuum", then I am probably better to switch the dizzy to a dual unit. But how can I know for sure? I don't have a vaccum guage (and I have no way of getting the engine to run, currently, anyhow).

Well, if anyone knows, I'd appreciate it. And if you don't -- well I won't be suprised. The 61-66 forum is likely to be ignorant as well, as they didn't have many 240/300 engines either.

later.......

 

It seems like you may have answered your own question. If your dist. has no mechanical advance it is the load omatic. If your carb doesn't have the spark control valve then it isn't for a loadomatic. If it was any good Ford wouldn't have discontinued it after one year so why don't you just get a dual advance dist. and hook it to ported vacuum.

 

You can use the later dual advance dizzy right now with no problems. The centrifical advance will be doing most of the work anyway. As far as the vacuum advance, you need to get a vacuum gauge and measure what's at the carb. Like Fordsix says if it's around 6" that's no good, if it's more like 15" then you're all set. Heck I don't even run a vacuum advance on my truck.

Barry