DUI pre-check!

[Brandonium]

Hey guys,

I've got a '77 sii, 345, 727, 1406 carb, 4bbl aluminum manifold and stock ignition system. I think I May encounter a clearance issue with my t-stat since I barely clear my air filter. Need some eyes on this before I even think of ordering. Does it appear as though it'll fit? I've been scouring these board and the bp boards but nothing that shows this tight of clearance to the housing itself.

Wouldn't mind a few eyes and thoughts on this.

 

[1975IH200]

Brandonium, I installed the dui on my 392 engine a few years ago. I have a write-up in the dui thread over on bp from when I installed mine. A few items you need to be aware of:

1. The dui comes with a thermostat housing that has the extra bolt hole ground off smooth. Now is the time to replace the old t-stat & gaskets.

2. If the water temp probe is in the way, it can easily be relocated to the drivers side of the t-stat housing. It comes with a bushing & plug in the port on the driver side. Just use these to relocate the probe. The wiring for the probe is long enough to reach easily, just open up the wire loom and release the extra wire length.

3. I used a dremel to grind down the casting flash on the upper radiator hose outlet, along in inner curve area that will be near the distributor cap. Also, rotate the radiator hose clamp accordingly.

4. My dui cap electrical port & vacuum advance can were orientated approx. 180 degrees opposite. This makes it difficult to fit within the area available. I simply used the dremel again to cut a notch in the distributor housing so that the cap electrical connection was close to the vacuum canister, effectively rotating the cap 180*. I have heard some duis come with this orientated correctly, but it is easy to remedy. I elected not to cut the locating 'bump' out of the dizzy cap (plastic) as this 'bump' fits into the dizzy body to keep it properly located. Therefore I cut the new notch in the dizzy body.

5. Air cleaner: my truck has the factory stock air cleaner housing, no issues with that at all. It looks like your air cleaner has enough room and you should not have any issue there.

6. I made my own ignition cable holders with black tie-raps.

All in all a very easy installation and well worth the cost.

I've added a few photos of my installation.

 

[Brandonium]

Awesome details. Looks like I have no reason to wait on purchasing. I'm really sick of my current ignition system giving me so much grief.

I'll go hunt down your post on bp. Did your dui come with a tach hookup?

 

[1975IH200]

Tach hookup, yes, each dui has a tach hook-up point at the electrical connector.
One pin is for 12+ volts in to power the ignition, and one pin is for the tach output.
Both connectors are provided with the dui.

 

[Brandonium]

Do you happen to know if the dui works with both ported and manifold vacuum? Also, does manifold vacuum have to be sourced from the carb or can it also be sourced from the manifold itself? My carb only provides ported vacuum which is why I ask.

 

[1975IH200]

Dui, or any distributor vacuum advance unit, will work with whatever vacuum source you provide as it can only react to the amount of vacuum provided. Of course, the amount of vacuum supplied by the engine, or lack thereof, May limit the amount of advance provided by the vacuum advance unit on the distributor.

Full manifold vacuum can easily be sourced from other ports on the intake manifold.

 

[Craig]

Dui pre check.

How much have I had to drink? Don't really know, then can I walk a straight line. Ok that's good, but I better walk or spend the night in jail.

Why not just do a mopar guts conversion?

 

[Brandonium]

dui pre check.

How much have I had to drink? Don't really know, then can I walk a straight line. Ok that's good, but I better walk or spend the night in jail.

Why not just do a mopar guts conversion?

I think I also have slop in the bushings. I've looked at the conversion but it just seemed easier to go the dui route. I didn't want to deal with trying something that while cheaper requires a little more work than what I might be capable of doing, if that makes sense?

 

[RMScout]

Personally, I don't think the dui's are a very good value. The module is old technology and the advance curve is one size fits all. The mopar pickup is not a difficult job, but to get the best performance you also need to recalibrate the mechanical advance. Bushings are pain, but if you have less than .003 side play you're good to go. Or get a rebuilt dizzy and drop in the mopar pickup. It's more work and research, but in the end you'd have an ignition system that's more powerful and modern than the old dui module with a distributor that fits and clears everything nicely.

 

[Brandonium]

Rm, I really wish I had the skill set to do what you're mentioning but I don't, and my list of things to do on my Scout is so large I feel I'd never finish if I dove into it.

IH, where was the optimal position that you used when stabbing your dui to ensure enough travel for timing? Just curious where your vacuum advance sits.

 

[1975IH200]

Here is a photo of my dui.

Small-dui - right side view copy

 

[RMScout]

rm, I really wish I had the skill set to do what you're mentioning but I don't, and my list of things to do on my Scout is so large I feel I'd never finish if I dove into it.

I can relate. Never enough time in a day.

 

[Brandonium]

When timing to 10 degrees btdc do you rotate clockwise or counter-clockwise? I'm trying to figure out how much room I need as space is snug. Also, how much of a turn gets you 10 degrees?

 

[FDChappie]

Turn ccw to advance and a 20 deg adv on the dizzy gets 10 deg on the crank.

 

[Brandonium]

Thank you! Exactly what I needed to know!!

 

[Brandonium]

So someone correct me with my logic on this.. I want to make sure I'm grasping how this works.

When you stab the distributor the rotor remains in a static position while the base rotates. The goal is to get that rotor pointed to a terminal on the cap that you can then designate as #8. From that point just follow the firing order and place the wires accordingly. So far so good?

So it doesn't really matter where the rotor winds up as long as it points to a terminal that you will use as #8. What's throwing me off is when people say that the distributor is off by a tooth. If the base moves and the rotor is static then why not just rotate the base to put the rotor in alignment with a terminal? Or maybe I should ask it this way..

In a world where you had unlimited space to rotate a distributor 360 degrees without interference..and you wanted to assign a different terminal on the cap as #8 (while keeping the rotor in the same position), could you not simply rotate the base?

Reason I ask is that I want to ensure I have a smooth turn for setting my timing, especially on a ccw turn. My current #8 has the power terminal on the dui hitting the radiator hose if I turn it a bit ccw. If I turn the base cw so that the terminal next to #8 is now #8, rewire accordingly then that gives me a little more room for a ccw turn. I know I only need 20 degrees of turn but I'm not the best at judging how much that really is and I want to be safe before I button this all down. I'm also trying to understand how someone can be off a tooth if the base can be rotated to put the terminal where the rotor is pointed. Unless of course it doesn't work this way.

 

[1975IH200]

Brandonium, any follow up on this item since last November?

Did you finish? Any photos of your installation?