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D and C Extreme’s Davis Unified Ignition Installed

Contributed by D and C Extreme

Meet Rusty, he’s our 1979 Scout II daily driver. Rusty,  is exactly that. It runs well, but I wanted more. To get more “oomph” out of a Scout, there’s only a few things you can do. Upgrade the induction (intake), ignition or exhaust. Since Rusty already sports a 4bbl manifold, the intake side is taken care of. We wanted Rusty to pass smog, so we didn’t want to mess with the exhaust. The only thing we had left was the ignition.

There are a couple of aftermarket ignition products for Scouts. From Jacobs, MSD, Petronix, Converted HEI units and Davis Unified Ignition (the new one on the block). We’ve ran HEI conversions in the past with Terrific success, but price and delivery time on those were terrible.

davis unified ignition
davis unified ignition

We couldn’t wait. Then, one day on the forums and we saw a topic about the new D.U.I. (Davis Unified Ignition) distributors. We were immediately happy to see that they were a form of the HEI conversions we used to carry, but used all new parts, and even came with an upgraded 50,000 volt coil.

 As a vendor we were interested to see what Performance Distributors of Memphis, TN was all about. Their website boasted that the Davis Unified Ignition distributor “is a compact, one-piece ignition system” for virtually all Scout V8 engines. They also said that the “Davis Unified Ignition. is virtually water, mud, and vibration proof because the electronic components are protected inside the distributor. All you have to do is run one 12 volt hot wire to the Davis Unified Ignition and you are ready to run!”

We ordered our first one, and about a week later it showed up via UPS. Immediately we were impressed with the packaging, and you know right off that the Davis Unified Ignition is not a fly-by-night company. The box is clean, well made and easily protects the Davis Unified Ignition. from the ravages of any carrier. Inside the distributor was packaged nicely with all parts and instructions very easy to find. Here’s what I got with my order:

  • D.U.I. Distributor (with Blue Cap, yes you can pick)
  • Live Wire Spark Plug wires (Extra Cost, in Blue)
  • New thermostat housing
  • Gaskets and hardware
  • Instructions

We were impressed, the D.U.I. looked great, but lets get it in, and see how it works.

davis unified ignition
davis unified ignition
davis unified ignition

The first part of installing the D.U.I. is to replace your thermostat housing. Simply remove the upper radiator hose and unbolt it from the block. Clean the surfaces, and install the provided housing (Yes, the D.U.I. comes with new gaskets, so don’t worry about needing to make a surprise trip to the parts store).

Next, remove the stock coil and coil wires (Do not remove the spark plug wires!) Make sure you mark the wires that came off the coil, the ignition hot (or positive side) in particular.

Then, remove the old distributor cap and vacuum advance hose, set them aside. Note exactly the direction the rotor is pointing. The folks at Performance suggest cranking the engine until the rotor points towards the fire wall , I pointed mine towards the water neck (which is not just close, it’s easy to mark with a piece of chalk, pencil or Sharpy)

With the rotors position marked in an easy to read place, remove the distributor hold-down clamp and then the distributor. As you pull the old distributor out of the engine, you’ll notice the rotor will turn. this is normal, but pay attention to where it ends up as it clears the motor.

With the cap off of the D.U.I. distributor, position the rotor to where it was when the distributor was just removed from the engine. Slide the distributor down into the engine. Be sure the rotor turns back to the original position (mark on firewall/waterneck). If the rotor does not point exactly towards your mark, remove it and do it again. (Our first attempt at this took 3 stabs to get it right). Why is this so important? The distributor engages the oil pump. If the oil pump drive does not engage, check that the rotor is pointing in the correct direction. If not, repeat the installation procedure.

davis unified ignition
davis unified ignition
davis unified ignition

If it still doesn’t engage, bump the engine over until the distributor drive drops into the oil pump drive.

Reinstall the hold-down clamp and bolt finger tight. If you’re D.U.I. is going into the engine, but not all the way in, check your engine temperature sender. My installation required me to remove it and put it in the new water neck housing (Yes, D.U.I. provided all the adapters needed to fit it in)

Once the distributor is fully seated in the engine, install the distributor cap and transfer the plug wires making sure that they are put onto the new distributor cap in the right order. (Note: If the wires get out of order you may experience an impressive (but harmful) backfire or two. Double check the firing order to make sure this doesn’t happen).

We decided to change out the spark plugs at the same this point, it wasn’t needed, but we don’t want to have to worry about anything ignition related for a long time. D.U.I. recommends that more performance can be gained if you open the plug gaps up to .055″. We used the stock .045, call it habit.

With that done, take your old coil wire (the ignition hot one) and plug it into the D.U.I. (Yes, Performance Distributors included new plugs and clips to insure a clean connection). Now is a good time to get a volt meter and make sure that your 12 volt wire is giving you a full 12 volts. There is no need to worry about any resistors (like they do in the olden days) The D.U.I. is designed to perform with 100% full voltage, and will give you the best performance when it’s supplied with it.

Once you have all the wires in place, start up the engine and set the timing. D.U.I. also recommend setting your initial timing at 12 degrees BTDC while the engine is at slow idle (600 RPM + or – ) and with the vacuum advance disconnected and the vacuum hose plugged.
The End Effect. We’ve said it before, and we’ll say it again, our ’79 was fast before, but it wasn’t this fast. We wish we could, but can’t give you numbers, all we can offer is our ‘by the seat of my paints’ views. That’s how you put it in. when you follow the instructions, the whole process is relatively simple, just don’t try it in a hurry (unless your experienced). We know some of the pictures make it look like a tight fit. In reality, its a very tight fit. At times we wondered if we would be able to adjust the timing, or if it would clear under the hood/air cleaner. But all our worries were in vain. When properly installed, we had plenty of adjustability and clearance. If you’re having problems, feel free to adjust the distributor housing until it faces the same as ours.

davis unified ignition
davis unified ignition
davis unified ignition

Startups: Significantly faster startup. Even when cold. If there is fuel in the carb, the Scout will start.

Case in point: We took a customer home from the shop the day after we got the D.U.I. installed, and while making a right turn, we mashed the pedal while rolling about 5-10 mph. Not only did the Scout jump, the rear end step out to the side momentarily. We were a bit surprised at that (never happened before), and the customer found quick/easy handle for the rest of his ride home.Low-end: My Scout always had good low-end power, so the difference wasn’t as noticeable up front. With that said, we will say that we do hear my rear tires slipping on a daily basis (yes, we’re an aggressive driver). We particularly like the 900-1200 jolt of power.

Midrange: The throttle response has definitely improved, the Scout no longer thinks about moving when the accelerator is pressed, it just goes. It is easiest to say that the Scout has plenty of pull and it comes when asked, before it was a sometimes hesitant.

High RPM: This is where we noticed the biggest difference, we got substantial increase in high-end power. Passing people is an easy thing, even without downshifting. Throttle response is quick and power is immediate (even with the Thermo Quad carburetor), before we had to force a downshift to get the Scout to move.

Fuel Economy: With the price of gas going up by leaps and bounds, we were particularly interested in our fuel mileage. Again,we have no numbers due to the fact that my speedometer hasn’t worked since we’ve owned the Scout. we can tell you that it has increased a ton. We drive my Scout every day. As noted before, We’re an aggressive driver. As with most Scout owners, we panicked when we saw the price of gas reach $1.99 per gallon. Before the D.U.I. installation we would fill the Scout up 1.5-2 times per week (19 gallon tank). Now, we fill it up once (maybe 1.5 times if I drive a lot).

Case in point: Today is Monday, we filled it only half way on Friday (it was on fumes ),($20 or 10.5 gallons, and it gave me just over 1/2 tank).  Today, after a full day driving on Friday, driving to find a Mothers Day present on Saturday, to Church and back on Sunday, and a full day of driving today, we still have 1/4 tank, and all we can say is WOW!

In the end, all we can say is that this D.U.I. conversion is like installing a set of Corbeau seats. Once you do it, you’ll never be happy with stock again. We love the power, the economy, and most of all, we love not worrying about the possibility of ignition failure.

davis unified ignition
davis unified ignition

Tidbits of information:

  • Cost of the distributor, with everything except the wires RETAILS for $444.75.
  • D.U.I. come with a 1 year warrantee on all units
  • If you’re vain (like me) you may choose your cap/wire color. Colors include: Red, Black, Blue, Yellow and Clear. There is no additional charge for this. (Wires don’t come in ‘clear’)
  • All D.U.I.’s come with a tachometer hook up (located right next to the power wire), so if you have a tachometer, or are planning to add one in the future, installation will be a quick one-wire plug.
  • Your stock spark plug wires will need replacing. Performance Distributors offers their own Live Wires for $95 additional (we opted for these).
  • Stock spark plugs will work with the D.U.I. system. Replacing the plugs with new ones is highly recommended when the conversion is done.
  • Please send back your thermostat housing when you’re done with the conversion, this will help keep the price for these conversion kits as low as possible. We offer a rebate for any housing sent back!
  • Neither Performance Distributor or D and C Extreme cannot guarantee the performance gains of any Scout as a result of the installation of a D.U.I. distributor. All we can do is give you what we’ve experienced when the conversion was done. To date, over 30 distributors have been sold, I’m sure you’ll be able to find a D.U.I. customer on the Binder Bulletin’s tech-talk forum. Just search for “D.U.I.”
  • Most orders take 1 week from time of order to delivery.

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