Duraspark parts needed, carb questions???

[kimcrwbr1]

holly carb

just wondering does the holly 350 have a ported vacuum as no vacuum when at idle because you need it for the switch to work

 

[skippy]

I have the manifold vacuum going to both the bypass and thermactor so it gets air only to the manifold is that how you have yours Skippy. I am going to put valve guide seals in then put in another cat but dont want to burn it out will adding air to exhaust manifold make it too hot for the cat

I'm just running the air pump straight into the back of each exhaust manifold,have no idea how hot it gets.The egr is blocked off with a aluminum plate and two homemade gaskets,the holley carb has the dizzy vacuum port and vacuum is nil at idle,but advances nicely as throttle is applied.

I use the bowl vent switch to control vapor canister to carb hose,the switch is closed when cold and open when hot,it was on original feedback carb bowl vent line.

I have the manual choke version of the Holley,works well.

 

[kimcrwbr1]

cool i believe that is how it is supposed to be the air helps burn unburnt fuel before it gets to the cat I am going to put the egr vacuum on the ported side of the carb to help keep the valves cool also at least give it a try right now I have the choke, cannister purge, and bowl vent switched with the ignition and gonna play with the ported switch for the vacuum it also has a elect switch thats closed until 130 degrees then opens

 

[Mudhound]

To Bonedoc: The HEI module that I am running is the older 4pin GM HEI (think 76 Camaro, 350 for the knucklehead at the parts house.) To wire it in is a "little" bit more complex thatn the P&P dspark box, but it is really easy. Just one thing, make dadgum sure to mount it on a piece of aluminum for heatsinking, and use the CORRECT heatsink paste, not just plain old Di-elec. tune up grease. You can google the info, for download/printability, over off of Bronco.com. It is one of the all time favorite mods. I don't have any "how-to" pics, but if you need me to, I can help with the wiring up. Oh, yeah. I used a set of plugs from a burned out Dspark box to connect my HEI to the factory wiring. No cutting wires and having to splice things for me, as that is one more posssible headache on a 26 1/2 year old truck that I don't want.

It should look kind of like this when done...

 

[kimcrwbr1]

yea Im gonna get the parts for this setup also I cant remember where but saw a way to mount it inside an old duraspark shell for the heat sink and make it plug and play keep it in my cab for future mishap

 

[bonedoc]

Hello again Mudhound, I know I sent a message for the part number on your hei module..would you have any info into installing and wiring it.

 

[bonedoc]

Thank you...I was just sending that last post when yours came over!! Thank you!!

 

[Mudhound]

Give me some time, and I will get the harness coding for you. As for "how" to put the HEI in the Dspark box, simply heat up the goop in the box, peel it out, and drill 2 holes in the shell to mount your module. Like I said above, use the exsisting pitails from the Dspark box to wire in the module for a TRUE P&P. I am using the heatsink off of an old CD player for the mount in mine.

 

[bonedoc]

Trying to locate the distributor adapter...looking on ebay...looking up the part numbers...any suggestions?

 

[RobbieD]

Trying to locate the distributor adapter...looking on ebay...looking up the part numbers...any suggestions?

I Durasparked mine a few months ago, and here's what I found for the adapter.

Check with AutoZone, for a Duralast P/N F960. It can be looked up in their computer system under a 1981 F150 4.9L (300cu) 2WD.

It fit perfectly, and I paid $4.99 for mine. Good luck on your conversion; it is a good thing to do for the old 2.8.

 

[bonedoc]

Thank you much RobbieD...any suggestions or pearls of wisdom before I tackle this? Thanks again!!

 

[kimcrwbr1]

I think you got everything you need I found a small harness in the boneyard for the distributor with a four and three round connector the wires werent the same color but they matched up from the durasparkto the dist perfect if you going with the other ignition I suppose you could possibly get the female four connector to wire it up let us know how it worked out Oh yea start early if you plan on getting it all done in a day and a set of wheels handy for parts just in case GL Kim

 

[RobbieD]

I don't know about any "pearls of wisdom" (as my oysters are ALWAYS empty), but I will give you some advice, and then tell you a little about how I did mine.


First, the advice.

Pull together all of the information that you possibly can before you start the conversion job. You do seem to be doing this already; good!

As you've already seen, there are several different ways of accomplishing different aspects of the 2.8L Duraspark conversion. Coils, carbs and tigers, oh no! Uh, sorry; wrong movie. Anyway, what I am telling you is, weigh through all of the information, and all of the details, make your own decisions, then get your complete plan, and parts, in place before you start the job.

You also have the '85 model, and I didn't see what transmission you have. Supposedly, there's a little more to wiring the '85; I know an '84 has the Duraspark (round) wiring plugs already in place, but I understand the '85 model doesn't. If you have the A4LD automatic, its overdrive function must be addressed.


OK, now my conversion. I've got an '84 Ranger, with the C3 auto (3 speed, no OD).

I bought the distributor, rotor, cap, Duraspark module, and can-type coil with a ballast resistor from a member here on TRS. As mentioned, I found the adaptor ring at Autozone (I researched it by crossing the application).

I also wanted to reuse my recently-rebuilt original Motorcraft 2150A carb. More research! A member here came up with a way to fabricate a manual metering block to replace the stock computer-driven solenoid. I made one and it works fine.

What about the emissions equipment? Guess what- MORE freakin' research. My truck still has the original catalytic converter, which I wanted to retain. The EGR was computer-controlled, so I removed it and fabricated a block-off plate. I kept the air pump, and just plumbed it straight to the cat. I just plugged the exhaust manifold tubes; it'd be a bear to plug the manifolds while still in the truck.

And finally, as part of my conversion I installed valve stem seals and adjusted the valves. It's easier done with the motor laid bare, carb out of the way, and well worth doing. The original seals were long gone, so my oil consumption was greatly reduced, the valves are much quieter, and I'm sure it helped the job-finished engine performance.

I couldn't be happier with the results on mine; and a lot of great people here helped me with advice and encouragement. This place rocks!

You've gotten some very good information from the others so far. Just remember, on the Duraspark conversion there are many options, several ways to do things; there's simply no set or one way to do it.

Sorry for the length of my post; but you sound like you're looking for all of the various information that you can get. Good luck, man!

Edit addition: Duraspark wiring harness plugs can be found in the junkyard on early '80s 4-cylinder Rangers.

 

[bonedoc]

Thanks again RobbieD, You are correct, mine is an '85. My 2.8L is a fresh jasper motor, put headers on it and eliminated the air pump tubing and cat when I put the 2 and 1/2 inch exhaust with flowmaster on it...sounds great when you get on it.....when it is running right. The motor has about 20,000 miles on it. The A4LD in it is fresh as well...actually twice...it went about 4,000 miles after the motor was replaced. Then it blew again about a week or so ago. The trans shop rebuilt it on warranty. The warranty was expired but they replaced it anyway and I believe they did because something was done incorrectly the first time because it works so much better this time around.
Anyway so with that said, I'm going to handle the torque converter lock up in the trans with a toggle switch. My transmission shop feels this is the best because the other options aren't as 'automatic' as written and with the toggle, he said the hydraulic pressure will cause the trans to chug and release if you forget the switch when coming to a stop, and then you can just switch it off prior to take off. I'm going to mount mine in the lower part of the dash just a few inches in front of the shifter. I usually drive with my hand on the shifter so...no biggie it will be right there.

I have the holley 350cfm carb already, just going to take Skippy's advice and go with the #50 jets, with the open exhaust and a nice open air cleaner it should work well.

I'm going to skip the duraspark box and go with Mudhound's suggestion of the early GM 4 pin module. I'm all about dependability...I love performance but need my s#@% to run. LOL!!

I believe that I can skip getting a harness, because I don't have round plugs on my '85 anyway and just make a harness from 16g wire and connectors. Please correct me if I'm wrong here.

Kim made a suggestion of something he is using with the three port vacuum port mounted on top of the thermostat housing to control the vacuum advance on a cold motor, it them switches to off the carb when it warms up. He claims it allows cold operation much easier. Living in the cold northeast, even though I usually warm it up this would be nice.

Again thanks all, this site does rock..has helped me tremendously!! If any of what I wrote doesn't make sense or is incorrect let me know. Going to autozone today or tomorrow to order the distributor, rotor, cap, and adapter, etc.

 

[RobbieD]

Sounds like you're on the right track with everything. Good luck, and be sure to let us know how it turns out.