Duraspark conversion.

[Bronco648]

For posterity, I used a Gates 7480 XL v-belt for the fan/alternator (no smog pump). It's ~48" long (as opposed to the Gates 7520 XL v-belt for the fan/alternator/smog pump which is ~52" long). I figured that any belt between 47" and 51" would work. But, I don't think I'd go any shorter as it looks like 47" would be very tight or too small.

 

[4x4prepper]

> The socket is too far forward to snap onto the ball.

I will go out and look at my B2 tomorrow morning and see what I did to solve the problem. I think I took a cable from a 1988 and used that instead, BUT, I have to double check as I did it 5+ years ago.

 

[4x4prepper]

> Can you explain, or post a pic, of how this is wired? I'm curious about where the ignition resistor goes.

This is the only picture on my computer, from 2018, before I started driving it, after I converted from the stock carb to a 1970s carb.

The external (white block) resistor is at the top of the stock coil, left in place. I cleaned and neaten things up after the picture, just a reference in case something lit on fire.

Two red wires on the (+) coil - 1 to resistor which is feed by factory harness - 1 to relay which is only hot while cranking feed by the white wire going along the firewall. If I get time, I will try drawing it out in a vector program and uploading it.

 

[Tym]

Great info. Definitely gonna watch this thread! My 2150 carb should arrive today and the dist. Over the weekend. Sourcing the other parts from NAPA. I hope this can be done as a bypass. In other words disconnect the computer and sensors, but leave intact so I can revert back to it if I have trouble. I’m just overly cautious as I don’t want to lose drive ability. Mine is an ‘84 so I think it’s a lot more cut and dried than later models.

Also wondering if I can keep my electric choke. I kinda like it.

 

[Shran]

Great info. Definitely gonna watch this thread! My 2150 carb should arrive today and the dist. Over the weekend. Sourcing the other parts from NAPA. I hope this can be done as a bypass. In other words disconnect the computer and sensors, but leave intact so I can revert back to it if I have trouble. I’m just overly cautious as I don’t want to lose drive ability. Mine is an ‘84 so I think it’s a lot more cut and dried than later models.

You could but I don't know why you would want to. You would have to put the old carb and distributor back in place and hook up all the wiring...that would be a hard pass for me... a lot of work to go back to something that sucks. I would remove it all and just stick with the Duraspark setup, and simply fix it if you have issues but that is just me.

 

[Tym]

You could but I don't know why you would want to. You would have to put the old carb and distributor back in place and hook up all the wiring...that would be a hard pass for me... a lot of work to go back to something that sucks. I would remove it all and just stick with the Duraspark setup, and simply fix it if you have issues but that is just me.

I agree, however with the scarcity of parts I had to order the carb and distributor from ebay (sight unseen), so I'm not 100% sure about them. Only way to verify is install, thus I would rather it not be a permanent install, if it is the downtime may be extensive.

 

[Tym]

Carb arrived. First observation is that it doesn't have the same throttle linkage. No attachment point for the kick down or "passing gear" linkage (pics below). Doesn't look to be easily swapped, if at all. '84 Ranger/Bronco II Shop manual shows kick down at bottom of linkage. Is there a way of rigging up the connection? Maybe a Pinto throttle cable system? The choke I think is a simple matter of swapping on my black plastic cap with bi-metallic strip onto the existing choke body rather than swapping the whole assembly. Forgive my ignorance and persistent questions, but I haven't dealt with naturally aspirated engines in almost 40 years, and I've got to figure out if I'm gonna keep this carb within the return window.....

Thanks,

 

[franklin2]

Carb arrived. First observation is that it doesn't have the same throttle linkage. No attachment point for the kick down or "passing gear" linkage (pics below). Doesn't look to be easily swapped, if at all. '84 Ranger/Bronco II Shop manual shows kick down at bottom of linkage. Is there a way of rigging up the connection? Maybe a Pinto throttle cable system? The choke I think is a simple matter of swapping on my black plastic cap with bi-metallic strip onto the existing choke body rather than swapping the whole assembly. Forgive my ignorance and persistent questions, but I haven't dealt with naturally aspirated engines in almost 40 years, and I've got to figure out if I'm gonna keep this carb within the return window.....

Thanks,

I know you want to save the old carb, but I am with the other poster, I would not want to use it again. My 84 was a manual transmission so I didn't have the kickdown issues. I have rigged it before on other Ford vehicles though.

1st thing to look at; That auxiliary lever that moves independently of the throttle and comes back and hits the kickdown rod. How is it attached to the carb? I don't remember how and if possibly it just unbolts. If it doesn't unbolt I would;

2nd. See if it's possible to use the baseplate of the old carb on the new carb. If it bolted right on, then problem solved. I am talking about the complete base of the carb that has the throttle butterflies in it. If you are a little unfamiliar with carb work, you might shy away from doing this.

3rd. Just forget about the kickdown linkage and don't hook it up. The trans will work fine without it, but I know having such a small engine, it's almost mandatory to kick down the transmission when you need power. You can get in the habit of manually downshifting it if the shifter will allow it without too much difficulty.

 

[Tym]

I know you want to save the old carb, but I am with the other poster, I would not want to use it again. My 84 was a manual transmission so I didn't have the kickdown issues. I have rigged it before on other Ford vehicles though.

1st thing to look at; That auxiliary lever that moves independently of the throttle and comes back and hits the kickdown rod. How is it attached to the carb? I don't remember how and if possibly it just unbolts. If it doesn't unbolt I would;

Thanks for the input. Number 1 seems the most viable, and I’ll have to check it. Seems like the kick down would have a spring so perhaps this is an anvil lever that I can modify and attach the kick down plus a return or resistance spring. Currently the extra “bell crank”is free moving, does nothing as far as I can tell.

I could handle the manual shift, not that anyone should pass while driving one of these, but the wife needs to be able to drive it and with more accelerator being able to kick it down on uphill grades is good, manually shifting would just piss her off.

 

[franklin2]

Thanks for the input. Number 1 seems the most viable, and I’ll have to check it. Seems like the kick down would have a spring so perhaps this is an anvil lever that I can modify and attach the kick down plus a return or resistance spring. Currently the extra “bell crank”is free moving, does nothing as far as I can tell.

That large flat paddle on the new carb is awful suspicous. You would think it was there for the same reason as on your original carb, to come back and hit the kickdown. But this situation is typical of China knock-offs. They get 90% of it right and fail on the small details. Sometimes you have to get creative.

 

[Tym]

Yeah I’m perplexed as to what that actually does. It free floats, but the cog close to the idle screw engages the throttle lever and moves it about an 1/8”. For what I have no idea.

 

[Tym]

So, here’s a question. I have a mid ‘70’s 302 that I thought about refreshing and dropping in the B-II. It has what appears to be a 2150 2bbl (and proper throttle linkage). Can I have that rebuilt and just swap jets to the proper size for the 2.8L or is it more complicated than that?

 

[franklin2]

The jets that are in the other carb are most likely what you need anyway, even though this engine is smaller. Don't go by the original jet size in the original computer carb, they are way oversize. That's how they controlled the fueling, by adding air with a bypass solenoid.

The china carb I bought was for a v8, and it runs fine. The biggest difference is the original carbs for the 2.8 where I believe a 1.08 venturi. Those smaller carbs like everything else 2.8 in the 1970's are hard to find. The smallest China carb I could find was a 1.21 venturi. Like I said it runs fine, but I can tell a difference at lower rpms. my throttle response is not there and it lugs a little bit. So I have to downshift sooner that I would expect. Most people would not notice it. If I had a 1.08 venturi carb it would have more low rpm grunt than it does.

But as far as jetting, it's fine with the stock jets that China put in it. I actually got 5 more mpg with the China carb than I did with the original computer carb disconnected. I ran the disconnected computer carb with the duraspark conversion for a year and it ran fine, but I noticed my fuel mileage wasn't the greatest.

I think you can look on the side of the carb somewhere and the venturi size will be stamped on it. You can do a google search on 2100 and 2150 carbs and get a lot of info on them. Try to get the smallest one you can.

 

[Tym]

I think you can look on the side of the carb somewhere and the venturi size will be stamped on it. You can do a google search on 2100 and 2150 carbs and get a lot of info on them. Try to get the smallest one you can.

Thanks for the info. I know the eBay carb is stamped 1.08. I’ll have to check my v8 carb. My distributor came in so I may try to convert everything but the carb and see how she runs for now. The evil TFI module, computer, and sensors are the parts that I’m trying to eliminate anyhow.

 

[Bronco648]

OK, trying to spin up some oil pressure but am having no luck based on the dash gauge. So far I've:

1. Tried two different (new) pressure switches. 1st one is a Standard Motor Products PS60T (Amazon) and the second is a ValueTech PS103V (Auto Zone). Both are supposed to fit the 2.8. When switching sending units, there is oil in the extension.
2. Checked the wiring to ensure it's sound. Grounding the white/red stripe wire results in the gauge going to to the top of the range (with key on).
3. Engine is completely rebuilt with a new oil pump. It spins easily.
4. The distributor is fully seated, the rotor spins and the oil pump drive shaft was installed.

Not quite sure what else to check. Having to drop the pan on a new engine would really suck. I did use a gasket and PermaTex Ultra Blue when installing the pump and pick-up tube. Having oil in the pressure switch extension leads me to believe oil is circulating but I'm stumped as to why the gauge doesn't register any pressure. When turning the key on, the needle goes to the top of the range and then slowly falls to the bottom of the gauge range (but never drops out of range).

Anyone have any ideas?

Is turning the engine over with just the starter not enough to register oil pressure (on the stock dash gauge)? I had a small leak at the oil filter adapter (resolved by tightening the bolt). So, there does seem to be oil going in/out of the filter.