Installing an HEI
distributor from Z&M Jeeps
into an AMC 360
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Once upon a time, I came across Zack
Heisey's modest
advertisement about his fresh-off-the-mill HEI-style distributor. The list of
parts he put in, and amount of work to put one together, was on par with DUI's famed product, and the price - less by far. All
together, it was a great reason to make a little dent in Zack's enormous
outlay in his purchase of warehouse full of NOS parts. The distributor
arrived promptly, just to sit on my dining table for a few weeks and keep my
wife all cranked up about all that $%^t that belongs in the garage and never
makes it there. Finally, time came to rip the box apart and pull the beauty out… |
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U.S.P.S. sure took care of the beautiful piece of work. The box
was all banged up and sported a gash on the side. The close-up inspection
revealed that two terminals were bent on the distributor cap, and one -
broken off. Big deal… HEI caps should be a dime a dozen, and ought to be sold in
every grocery store in town. |
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I needed to buy a new set of wires, anyway, so off I went to my
friendly Kragen. I tried my best to avoid questions from the parts dude about what
vehicle do I need my stuff for. This process became more involved when I
found that the F350 wires are definitely way too short, and the parts store
managed NOT to stock Chevy big-block wire set! |
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Anyhow, the wires were eventually found, as well as ACCEL
super-duper cap that came at a $25 premium. No instructions were necessary to
transplant coil, cover, and terminals from the once-great cap that came with
the distributor to ACCEL fare. Here's the distributor assembled with ACCEL
cap. |
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Here's the under-hood view of the stock AMC/Ford distributor
with a set of MSD Super 8.5mm wires - all have to go… They will end up
boosting the ignition in the 1968 Wagoneer. |
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MSD-6A ignition box also has to vacate the premises - I'll miss
it greatly despite the fact that it hasn't produced a spark in the last three
years, after getting fried by shorted MSD Blaster coil. Jury's out on what to
do with it - send to the factory for repairs or just trash it. |
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Along with MSD stuff, the "true love of a full-size jeeper," the Duraspark
ignition box will vacate the premium space on the left inner fender. |
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OK… here's the parting shot with the stock distributor in place.
Wires and vacuum hose are already off. |
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Distributor retaining nut requires a special wrench to undo -
which is gone in the dark corners of my garage. An offset Take a note of the direction of the rotor! If you want your engine to
start right up, it is a good idea to have the rotor pointing to the same
spark plug terminal as in old distributor. |
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Here are two distributors, HEI on the top and stock on the
bottom, for comparison purposes. Rotor in the new distributor is lined up
similar to the old one. I noticed that the tab for the oil pump drive is extending about
1/32" past the bottom of the shaft, compared to ~1/64" recession in
the old distributor. That may lead to the next step… |
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Per Zack's instructions, if the distributor does not seat fully
in the bore, a washer should be used between the bore face and the ring on
the distributor casting. Big deal… but where do you find a washer with
1" I.D., and ~1.125" O.D.? Fortunately, I had the big steel washer
in my fasteners bin - but it had to be chopped. The only suitable tool was
the 4.5" angle grinder with a cut-off wheel. The resulting heptagon was
rounded off, and flat surfaces trued, with a file. |
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OK, time to toss it in. Here's the first look of the HEI
distributor mounted in the AMC 360. Future issues are apparent: the angle of
rotation of the distributor is limited by the radiator hose on the left, and
power steering pump on the right. Let's see if we get lucky… Also, the two
terminals near the P/S pump will require straight-up terminals on the plug
wires - another custom item. |
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Here's the view from the top. Doesn't look too bad, despite the
clearance being pretty tight. Started routing and connecting the spark plug wires. NOTE: big-block
Chevy wire set is not the ideal match; the set from Borg Warner seemed to
have two really long wires, and the rest - of nearly the same length. |
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Here, all but one ignition wires are connected. There's no way
to use the Chevy set and have them routed nicely and tidily in the engine
compartment; the #4, #2, and #1 wires are laid … well, the best way possible. |
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The beauty of HEI lies also in a possibility of a single-wire hook up.
The black cap on the distributor has two terminals, marked BATT and TACH -
very self-explanatory. In any case, you can run the 10-12 GA wire from the
BATT terminal on the distributor to the connector that fed power to your old Duraspark module, the one with one two wires.
Depending on the year, it will be a 10 gauge red or yellow wire. Check
it with a voltmeter or test light. It should have no power with the key
off and power when the key is on. |
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Here's my temporary run of the distributor power. I simply ran a
piece of wire between the terminal in the ignition
harness that led to the red wire. When everything is connected together, stick the key in the ignition…
Feather the gas pedal… turn… she fired right up!!! |
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OK, it runs. My first dib at setting the timing right revealed that
the light's bit the dust. A quick run to Sears and $35 later, timing found to
be waaaay off. Need to move the wires around the
distributor cap… Pull the wire, and… THE ACCEL CAPS SUCK! Three terminals pulled right off the cap, the inner parts fell into the distributor, and upper
- stuck in the wire terminals…. Not good… |
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I couldn't leave the jeep jammed under the gate at my garage apron, so
it had to be fixed immediately. I reinserted the terminals, and soldered them
together - I strongly recommend doing this on ANY HEI cap that seems to have
anything other than top-notch terminals. Chevy guys suggested using Borg
Warner caps - cheaper by far, and never a quality issue. Double-check your soldering job! |
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OK, things are more or less on the right track now. Two shots on the
right show my temporary placement of wires and terminals. The #4 wire is really
tight, and no way of laying it better. The #1 wire has to snake around the
distributor, to keep from chaffing on the P/S pump pulley. The #2 terminal is
jammed in, but it's just a matter of time until it pops loose. Timing again… With one allocation of ignition wires on the distributor
cap terminals, the ignition is very late, and the engine barely idles. When I
moved the wires one notch counter-clockwise, the latest I could do is about
20 degrees BTDC - way too early (the heater hose limits the further
adjustment of timing). Engine idles nicely, but it'll ping badly under load. |
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The only solution is to re-mesh the distributor and camshaft gear by
one tooth clockwise. It took approximately 30 minutes to remove the distributor, cap,
wires, rotate the distributor shaft one tooth clockwise, and put everything
back together. Now I have approximately +/- 30 degrees of timing adjustment. Before adjusting timing, remember to disconnect and plug the vacuum
advance hose! By the time you're finished, you won't need a book to tell the
firing order of the engine - 1-8-4-3-6-5-7-2! P.S. Zack suggests using a standard-length AMC V8 ignition wire set,
with HEI-style terminals installed. Some of the auto parts stores sell the
individual terminals; alternatively, they can be purchased from MSD Ignition website,
part # 8848. |
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P.P.S. After having
taken my jeep to the woods last weekend, I am happy to report that she has
not missed a beat. Starts a bit easier, and the stink is all but gone from the exhaust.
Has not flooded once, despite going from sea level to 8k ft and pitching the
nose 30 deg up. Neither did it ever ping, despite running on a warm side
while going up the grades on I-15. Can't say if my gas mileage changed or not
- it took 13.1 gallons per 128 miles driven on the way there, and it included
70-75 mph highway joint and 20 miles of climb at 40-50 mph in the 2nd gear. |
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Peter Matusov,
May 2003 ©
Three Rivers Junction