Gary/Jack,

I asked a couple of questions with regard to my 2100, in another thread (which you probably don't frequent) located here: Ford Truck Enthusiasts Forums - Search Results

Any comments from you would be much appreciated.

Thank you,
Mookie

 

Unfortunately, that link doesn't work for me.

 

My apologies. The correct link to that thread is here.

https://www.ford-trucks.com/forums/1...2100-carb.html
.

 

I responded. Hope it helps.

 

I tried to "rep" you Gary, but am in "rep jail".

 

Thanks, David. It is the thought that counts.

 

I am in the middle of wrapping up my Duraspark II conversion on my 86 F150 300, and I have run into a few questions.


The carburetor I went with is a National ND1507


(YFA 1979-86 300" Eng W/Climatic Choke)


Carburetor Lookup


I have the truck up and running. The hot idle is adjusted around 800RPM and the timing is set to 6 degrees before top dead center.


I found a vacuum port that does not receive vacuum until I give the truck gas, but the vacuum port seem to only give a small amount of vacuum.


1) Does this look like the correct port to you?


I also tried the port below the one the vacuum tube is currently connected to, but the timing jumped up to around 14 degrees below top dead center at idle.


2) Is this correct?


I am not planning on hooking up the EGR valve at this time considering the valve no longer works (It was frozen in place when I took it apart this weekend.).


3) Do I need to hook up any other lines like the second port on top of the PVC valve to anything?


I do plan on reconnecting the vapor canister, but it will not be hooked to any other vacuum lines at this time.


Thanks in advance for your help!


Thanks,
Cody

 

The "ported vacuum" on those carbs doesn't give full vacuum and won't work well for the vacuum advance. So you are pretty much stuck with the one that has vacuum at idle. And it should make the advance jump when you plug it in - that's normal.

As for the "port" on top of the EGR valve, I think you'll find that it is closed off and there's no need to connect anything to it.

Now, for setting up your timing you want the initial advance to be as much as it can be without making the engine hard to turn over. So, try at least 8 degrees and maybe even 10. You'll have to drop the idle speed as more advance means the engine runs faster. And, make sure the 8 or 10 is dialed in with the vacuum advance disconnected and plugged.

Once you have the initial advance set up where it starts and idles correctly connect the vacuum advance. Once again you'll have to drop the idle speed. Then go for a drive and listen closely to the engine under part-throttle acceleration. If it pings you'll want to increase the point at which the vacuum advance starts working, which is done by slipping a small (3/32" I believe) Allen wrench into the port on the vacuum advance canister. Once you get it into the screw inside the advance turn it 1 turn counterclockwise and run the test again. Keep doing that until it no longer pings on light throttle. At that point you have the maximum timing and, therefore, maximum economy the engine will deliver.

 

Gary,

Wow, your knowledge base for these engines is unbelievable. You do not know how much I appreciate the response.

So first I need to disconnect the vacuum advance on the distributor and plug the port currently in use on the carb.

Next, I need to set the timing to 8 to 10 degrees be for top dead center.

Then, reconnect the vacuum advanced on the port below the one it is currently connected to.

At this point, go for a test drive and listen for pinging.

If it pings, pull the vacuum line from the vacuum advance on the distributor and insert a 3/32 allen wrench and turn 1 full turn counterclockwise.

Repeat this process until any pinging is gone.

Am I understanding everything correctly?

I have another few questions?

What hot idle speed would you set to with the above configuration?

What cold idle speed would you set to?

Do I need to do anything with the top port on the PCV valve?


Also, does the white painted screw right above the EGRspacer need to be adjusted in any way? I should be adjusted by national to thefactory specification.

Thanks,
Cody

 

Cody - I'm just an old man with a bit of experience. The real experts haven't chimed in yet.

Anyway, yes that's correct. However, once you set the timing the engine's idle speed will come up. And when you plug the vacuum in it'll come up further. So you'll have to adjust that before driving. The recommended hot idle speed should be on a label on the filler panel ahead of the radiator, but it depends on what transmission you have. An auto will need to be set in gear and 600 to 700 RPM is about normal. And, that'll work for a manual tranny as well. The cold idle speed is usually something like 1500 in the specs, but it should also show on the label.

The top port isn't really a port. It is just a casting that isn't open to anything.

As for the screw, I don't know what that is. Does it show in a pic?

 

Gary, I think he's talking about the idle mixture screw, it's painted white and is just to the left of the capped-off vacuum port above the EGR valve.

 

Yes, I am afraid I may not have been clear, but you are correct. I was wondering if anything needs to be adjusted with this screw?


Thanks,
Cody

 

Thanks for the reps, Cody, and you're welcome!

About adjusting that screw... yes, you will probably want to fine-tune the adjustment at some point, but you should do some homework on adjusting the idle circuit mixture screw(s) on carburetors... using a vacuum gauge is probably the best method but a tachometer can also work. Do some research on what you're wanting to do before you do anything and just leave it for the time being, it should at least function where it's at right now.

About the smaller hose connection on the PCV valve... some configurations from the factory used that and others didn't. If you don't have any stray hoses laying around, just leave it capped off for the time being. Much can be told about how it came from the factory by looking at the label on the radiator support under the hood (and the idle speeds should be listed there, too).

Oh, and welcome to FTE!

BTW since you're new here... it's generally not cool to hijack somebody else's existing thread with your own questions; best thing to do is start your own thread, click the button at the top of the subforum to which you want to post.

 

Ctubutis,

I sincerely apologize for hijacking this thread. My intent was not to add another Duraspark II question thread. In hindsight,I should have just created my own thread.

You don’t know how grateful I am that youguys are taking time out to help me with my project.

I have done research for several months (severelyticking my wife off at times) to get all of the components I need for thisconversion. I thought I had everything figured out, but I always find one morequestion that I just can’t seem to find an answer for.

With that being said, I create a new threadwhen I need additional help. Who knows maybe some of the photos I post willhelp someone else on their conversion.

Thanks Again,
Cody

 

Yes, thanks for the reps. And I'm glad Chris understood your question about the screw. I didn't have time to go back and study the pics as another FTE'er (Prashant) had just called and was rolling into town.