Modern distributor W/ vacuum advance, 4000 4 cyl

[blue_tractor_man]

This must be an unusual subject, because I have searched the forum and cannot find anything posted about it.

Maybe some of the tractor pullers have this figured out.

I am looking for an electronic ignition distributor to go on my 1964 Ford 4000 tractor. It has a 172 cubic inch 4 cylinder engine. I want a distributor that has both mechanical and vacuum advance. My purpose is to extract the maximum fuel economy over a wide range of RPM's. I want to be able to tune both advances to suit my needs.

I am using a Pertronix electronic module at this time. The ignition points in the factory distributor caused a certain amount of drag on the point lobes, and now the loss of the drag on the lobes prevents the mechanical advance from working as it was designed. The mechanical advance uses leaf springs rather than coil springs, and the distributor does not have a vacuum advance. These little leaf springs do not seem to be a very good design. The 1965 and later Ford tractors were equipped with a vacuum advance, but I do not think that the distributors were interchangeable, as the 1965 and later tractors were built in England.

I read several posts about the better fuel efficiency of the 1965 3 cyl tractors compared to the 1964 and earlier 4 cyl tractors. I have looked at the Nebraska Tractor Tests fuel consumption, and unless I am reading it wrong, there is very little difference between the two models. I think I should assume that the Nebraska Tractor Tests were done at nearly full throttle, which would negate the advantage of the vacuum advance.

My neighbor had a 1965 3000 and he could bushhog a lot more than me on the same amount of fuel. My tractor hogs the fuel.

I am open to any type of electronic distributor that will give me the ability to set the mechanical and vacuum advance rates to suit my tractor. I have a dynamometer available.

The old style distributor for the 172 cubic inch tractors is no longer available from Ford-New Holland. It has been superceded with what I think is a Mallory or Accel unit. The superceded part does not have a vacuum advance. I have seen one, but I cannot remember which brand it was.

This may seem like a lot of trouble to go to for an old tractor, but I really like my 4000. It has a live shaft, power steering, and a 5 speed tranny. I just wish I could squeeze a little more fuel economy out of it.

Thanks in advance for the help.

 

[Dean]

Not to say that the addition of a distributor with vacuum advance and centrifugal advance might allow a small improvement in fuel economy, any increase will be rather insignificant.

Alternatively, you could replace the carburetor with the so-called small carburetor from an 8/9*0 series tractor and realize a noticeable decrease in fuel consumption for the cost of an insignificant loss of HP at full throttle.

Dean

 

[souNdguy]

yup, i've done this on my mowing rowcrops.. small carbs, works fine.

 

[JMOR]

(quoted from post at 13:43:40 01/07/15) This must be an unusual subject, because I have searched the forum and cannot find anything posted about it.

Maybe some of the tractor pullers have this figured out.

I am looking for an electronic ignition distributor to go on my 1964 Ford 4000 tractor. It has a 172 cubic inch 4 cylinder engine. I want a distributor that has both mechanical and vacuum advance. My purpose is to extract the maximum fuel economy over a wide range of RPM's. I want to be able to tune both advances to suit my needs.

I am using a Pertronix electronic module at this time. The ignition points in the factory distributor caused a certain amount of drag on the point lobes, and now the loss of the drag on the lobes prevents the mechanical advance from working as it was designed. The mechanical advance uses leaf springs rather than coil springs, and the distributor does not have a vacuum advance. These little leaf springs do not seem to be a very good design. The 1965 and later Ford tractors were equipped with a vacuum advance, but I do not think that the distributors were interchangeable, as the 1965 and later tractors were built in England.

I read several posts about the better fuel efficiency of the 1965 3 cyl tractors compared to the 1964 and earlier 4 cyl tractors. I have looked at the Nebraska Tractor Tests fuel consumption, and unless I am reading it wrong, there is very little difference between the two models. I think I should assume that the Nebraska Tractor Tests were done at nearly full throttle, which would negate the advantage of the vacuum advance.

My neighbor had a 1965 3000 and he could bushhog a lot more than me on the same amount of fuel. My tractor hogs the fuel.

I am open to any type of electronic distributor that will give me the ability to set the mechanical and vacuum advance rates to suit my tractor. I have a dynamometer available.

The old style distributor for the 172 cubic inch tractors is no longer available from Ford-New Holland. It has been superceded with what I think is a Mallory or Accel unit. The superceded part does not have a vacuum advance. I have seen one, but I cannot remember which brand it was.

This may seem like a lot of trouble to go to for an old tractor, but I really like my 4000. It has a live shaft, power steering, and a 5 speed tranny. I just wish I could squeeze a little more fuel economy out of it.

Thanks in advance for the help.

"I am using a Pertronix electronic module at this time. The ignition points in the factory distributor caused a certain amount of drag on the point lobes, and now the loss of the drag on the lobes prevents the mechanical advance from working as it was designed." Really? How so? Yes, I need convincing.

 

[Ultradog MN]

Most of the 65 and later tractors were Not built in England. They were built in the US though yes, some of them were built in England and Belgium.
They did have vacuum advance. A distributer from a 5000 might work as they were also 4 cylinder.
You would have to rework it some - turn the barrel down so it fit into your block and rework the shaft for the drive gear.
A little work but I've seen that done - an 8 cyl Mallory in a 4 cyl for racing cars, etc.
Ultimately though I think the others have a better idea and that is to put the smaller carb from a 1955,56 800 or 900 on it.
You would be hard pressed to notice the lack of HP but would gain a noticeable increase in fuel economy.

 

[blue_tractor_man]

Soundguy,

That's interesting that the Ford engineers would put a too large carburetor on a tractor, with farmers having to buy expensive gasoline. Why did they do that? Maybe to squeak a tad more horsepower out for the Nebraska Tractor Tests? What year did they start putting the larger carburetor on the 172 CID engine? Do I need to change the intake manifold to one designed for the smaller carburetor?

Is there anything else that can be done on my tractor to increase fuel economy? Head work? Exhaust?

 

[blue_tractor_man]

I don't have any way to prove it, but my thinking is that the drag on the point lobes must have some impact on resisting the outward movement of the weights. I can tell you on my tractor, that the springs seem nearly useless until the weights put some pressure on them. In other words, the weights have slack in them until they move out and touch the springs.

If memory serves me, I checked the timing after installing the Pertronix, and it seems to me that the amount of mechanical advance was reduced, leading me to believe that the weights moved out some without the back drag of the points.

Maybe someone will test it and let us know.

Are weights with new springs available?

 

[JMOR]

(quoted from post at 22:50:56 01/07/15) I don't have any way to prove it, but my thinking is that the drag on the point lobes must have some impact on resisting the outward movement of the weights. I can tell you on my tractor, that the springs seem nearly useless until the weights put some pressure on them. In other words, the weights have slack in them until they move out and touch the springs.

If memory serves me, I checked the timing after installing the Pertronix, and it seems to me that the amount of mechanical advance was reduced, leading me to believe that the weights moved out some without the back drag of the points.

Maybe someone will test it and let us know.

Are weights with new springs available?

eights swing out to give more mech advance. Weaker springs give more advance at lower rpm

 

[MarkB_MI]

I seriously doubt adding vacuum advance will give you any noticeable improvement in fuel economy. Vacuum advance was used on automobiles because most of the time they're only using a small amount of their available power. For a tractor under load and running at PTO speed, the vacuum is pretty low even at, say, 3/4 throttle.

I assume you're already tried leaning the main jet. Have you checked compression? Are you sure all four cylinders are firing? (It's not easy to detect a miss with these tractors.)

 

[Fordfarmer]

The bigger carbs start with the switch from the 800 &900 to the 801 & 901 ('58?). I wouldn't call it "too big", they were just somewhat bigger. And yes, it was done to get a few more h.p. Fuel economy wasn't as big an issue then as it is now.

 

[Dean]

You can install the earlier "small" carburetor from a 8/9*0 series engine on your later 172 CI engine without changing anything else aside from adapting the larger air filter tube to the smaller carburetor.

Dean

 

[Dean]

You can buy a replacement advance mechanism or a complete replacement distributor.

That said, the quality of new aftermarket parts is dubious at best.

Dean

 

[blue_tractor_man]

I haven't checked it lately. I'll do that soon.

Thanks.

 

[Indiana Ken]

The timing can change with the installation of the electronic module since the trigger point may not match that of the point system. In a similar manner you can change the timing by opening up the point gap. The timing should always be checked and set as required after installation of new points/modules etc. I would not expect the electronic module to change the action of the advance mechanism.

Note, you are wanting to add vacuum advance to reduce fuel consumption however, a vacuum advance is not in play when the tractor is operating under load and using the most fuel. As a suggestion; you may want to optimize your exsiting distributor before going to the effort/expense of engineering something that may or may not offer a significate benefit:

The centrifugal advance sets (adds to the static setting) the timing for efficient operation at the engine's rated power/RPM range. In the event the engine is lugged down the advance system pulls back timing to prevent spark knock. Since you have access to a dyno you can determine the best timing for the power level and RPM you want to operate the tractor. With todays higher octane fuel the engine could likely run slightly more timing than the OEM spec calls for. Lets say, you find this setting to be 4 degrees advanced from the OEM specification. Now, remove 4 degrees of timing authority from the advance system and set the static timing at 4 degrees advanced. This allows for the best timing at power and also advanced timing at no/low load/low speed with the exsiting system. Note, since the static timing is increased you will need to be mindful of spark knock when loading at very low RPM. Assuming satisfactory operation and reduced fuel consumption, you have two options: 1) Keep the orginal distributor and take full credit for your skill or 2) Spend more time and money to see if additional gains can be had using a vacuum advance.

 

[blue_tractor_man]

Thanks Indiana.

I'll do some more work and figure out if I can advance my timing a little more with modern higher octane fuel.