DUI in the mail!
- Thread starter 1967JMG
- Start date
While I can't help you on the vacuum port for the DUI, generally you should use ported vacuum for a vacuum advance dizzy. Otherwise you'll have to much advance at idle and will never be able to get the car tuned up right.
You'll love the difference between a modern electronic ignition (DUI, DS2, Pertronix) over stock. It'll seem like a brand new car.
You'll love the difference between a modern electronic ignition (DUI, DS2, Pertronix) over stock. It'll seem like a brand new car.
arty: that will go nicely with your upgrades that you already have. defenetly more modern.
350kmileford
Well-known member
Might as well spring and get new plugs at the same time if you hadn't already planned for it. Yep, when I put in my DSII (not even DUI) it made my engine come alive.
Set your expectations high and watch them be surpassed
Set your expectations high and watch them be surpassed
There has always been a debate over which is better, hooking the distributor to ported vacuum, or to manifold vacuum. Some say ported vacuum must be use, while others say you need to use manifold vacuum. I recommend using which-ever works best for your application. If the motor runs better on ported, great. If it runs better on manifold vacuum, that's fine too. There is no right or wrong answer. Try both and see which one your motor likes best. In general terms, ported vacuum results in lower emissions, while manifold vacuum results in lower engine temps. The engine will idle a little higher on manifold vacuum, but this can be corrected by adjusting the idle speed on the carb.
Plug gap .045-.055
Plug gap .045-.055
1967JMG
Well-known member
Sounds good to me! By the way, I just got it today! It looks great! I have the day off tomorrow so we'll see what kind of trouble I can't get into with this thing! 
Also, the dyno runs where you compared all the pony carbs, it was made mention of that manifold vacuum yielded far greater results. With my current mod's would it be safe to assume (Key word is assume) that I would get better performance as well by using manifold over ported?
Also, the dyno runs where you compared all the pony carbs, it was made mention of that manifold vacuum yielded far greater results. With my current mod's would it be safe to assume (Key word is assume) that I would get better performance as well by using manifold over ported?
The stock Load-O-Matic distributors don't have mechanical advance (centrifugal weights that swing out immediately as rpm's are increased), instead they rely on a vacuum advance canister which senses Venturi vacuum. This system has two drawbacks. First you are limited to a carburetor that can provide the proper vacuum signal, such as the Autolite 1100 with a Spark Control Valve. Secondly, the vacuum advance canisters react slowly to the weak venturi vacuum signal. As such, the stock LOM dizzys are notorious for soggy acceleration. While the Petronix may increase spark quality, you're still stuck with the poor operation of the LOM dizzy. Finally if the Petronix unit fails it can't be repaired, which means you have to purchase a new one. If you're on the road or use your car as a daily driver, this may be a problem since most parts stores don't stock the 6 cyl units. Therefore IMHO, the DSII and DUI are much better choices. However the Petronix does have one advantage..... it maintains the stock appearance, which is critical if you are doing a full on restoration.TheDude":xlqmxj3q said:
1967JMG
Well-known member
WOWWWWW!!!!!!!!!!!!!!! huge difference with the DUI! i love it! much more torque and the sound seems alot throatier now! Even my 5th gear pulls harder! I have it hooked up to the manifold vacuum and as i expected the idle is a little high so a little bit of tuning and I'll be ready to go!
That's what I want to experience, I still have the stock LOM and a 1100v carb, the carb is great but I can tell i'm not getting enough from the LOM. that and it SUCKS when the can on the LOM dies on the road!! had to go 20 miles in flagstaff (thank gooodness for gps phones) to get a new can.1967JMG":cv662qil said:
JMG have you kept track of your mileage before? I'm curious if you see an increase and how big it might be (even 2mpg is big).
I think I'll just get it now while I might be able too... :roll:
1967JMG
Well-known member
As soon as I get my carb tuned I will keep track of my gas mileage for the next few tanks. When the only mods I have were the T5 and my new rear gears I was getting near 27mpg's in the city. After i did the cam, OZ head, and carb it went down a bit. So, I hoping now that I have the DUI it will increase again(as long as I can keep my foot off the floor). The car feels like it has alot more torque (which we all know mean the car wont be struggling as much to get up to speed) so we'll see what happens, and I'll be sure to keep everybody on here up to date as well.
yodabiri":2yio9kft said:
I agree, 14-16 in the city is more like it & 22-24 on the highway if all your A/F ratios are spot on.
Best of luck with your DUI. When you have the fire at the right time & plenty of it the results will be very positive. Bill
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