(F100) DUI Ignition Installation In A Ford 351W V8
By Jimmy Chambers
This is the
installation of a new DUI ignition system in to a 351W in my 63 F100. It is
currently running a Duraspark II system from the donor truck that I took the
engine and tranny from, which was a 1984 F250.
reason that I wanted to install the DUI set-up was to clean up the engine
compartment by eliminating the external coil, ignition module, and extra
I have also
converted this truck over from a generator to an alternator, so constant voltage
is not an issue anymore.
thing I did was to check the initial timing. It was at 12 BTDC. I then removed the cap and plug wires
together so that I would know where #1 was and could follow them around when
wiring up the new unit. Next, I marked where the rotor was pointing, I then
removed the rotor, cap adapter and distributor hold-down. I then slowly pulled
up the distributor paying attention to which way the shaft turned as it cam off
of the cam gear so that I would know where to point the rotor on the DUI unit
when installing it into the block.
Next, I removed the cap from the DUI unit and
lined up the rotor to point to where the old one did as it came out of the
block. I positioned the vacuum advance so that I had room to turn the distributor
both ways to adjust the timing later on. I then inserted the DUI into the engine and like on many Ford engines,
it didn’t drop onto the oil pump shaft, so I bumped the starter and it dropped
on in. I then installed the hold-down clamp and bolt finger tight.
reinstalled the cap and plugged in the module to cap plug.
I then ran a
12 gauge wire from the ignition wire at the firewall I had 12v there so I
didn’t have to bypass the factory resistor wiring. The DUI unit requires 12V to
14V for optimum output.
Next it was
time to install my new Live Wire set of plug wires. These are a really nice
spiral wound plug wire with a nice high temp shielding over the wires. They
come preassembled and are numbers for each cylinder. I opted for blue to match
the truck and engine.
installing the plug wires, be sure to apply the supplied dielectric grease to
both boots on each wire. This will help seal them from moisture and allow them
to be removed from the plugs and cap much easier if they need to be removed for
a plug or cap change. After installing the wires, I used the really nice billet
aluminum separators to keep them organized neatly. These too were from
It was now
time to fire it up, so I blocked off the vacuum advance hose and cranked her
up. I then readjusted the timing to 12
degrees BTDC just like the Duraspark unit was. This is what the instructions
say to set it at.
DUI distributor has the advance curve custom set for your application for
things such as vehicle weight, camshaft, octane, compression, etc. This is done
and ready to drop in when you receive it. Mine is set to 22 degrees of total
advance so with the 12 degrees initial advance, I have a total of 32 degrees.
setting the timing to 12 degrees, I tightened the hold-down and rechecked to
verify that it was still at 12. It was so I hooked up the vacuum line to the
advance. I used ported vacuum for my application.
thing that I noticed is that it was idling almost 500rpm higher with the timing
set the same as the old unit. It is obviously firing much stronger from the
increased dwell time in the module and hotter coil. So I turned the idle down
to where it was before. The throttle response is much crisper and it revs
quicker than before.
I must say that I am quite impressed with
this system. The added power is quite noticeable and the engine compartment is
much cleaner without all of the Duraspark wiring, coil and module. It is a good
looking unit with obvious performance benefits. I would recommend this system
to anyone wanting a better performing, easy to install ignition system.
The instructions say that a 13" air cleaner
must be used to clear the cap, but the 14" that I have on there right now is
not a drop base and I have a 1" spacer under it. After the bodywork and
painting is done, I will reinstall my drop base unit that uses a 5" element to
see if it will clear with the spacer.