Setting Aftermarket Ignition Systems
These instructions are provided for professional mechanics when replacing the OEM Ultima
®
fixed curved ignitions after the warranty period
expires.
Installing aftermarket ignitions during the warranty period on any Ultima® Shovelhead engine will void your warranty.
(For TOTAL
TIMING use the information supplied in this book and not from any ignition manufacturer other than Ultima
®
.)
Timing Marks
Ultima
®
Shovelhead Engines are supplied with 4 reference timing marks on the flywheel to identify crankshaft location when viewed through
the timing hole plug. These marks are as follows:
12
T:F
1.
3 0
R 2. A
R.
3.
4.
Mark 1.
= (T:F)
T
op
D
ead
C
enter on the
F
ront cylinder—
The TDC mark is used for most electronic ignitions as the reference point to begin the
static timing process
. When using this mark for timing you must be on the compression stroke on the front cylinder and both valves
should be closed. This mark is also used when checking total timing with a Dial Back type timing light.
Mark 2.
= (NOTE 1) Advanced Timing mark for the front cylinder — This mark is used for ignitions that have mechanical advance weights as
the reference point to begin the static timing process.
(You must still rotate the point cam or trigger rotor to full advance to use this
mark and static time properly.)
This mark is also the reference when using a regular timing light to check total timing
for all ignitions
. When checking timing with a light you
must use the front cylinder plug wire and turn off any multi spark functions your ignition may have. You must also rev the engine high enough
to bring the system to full advance to check properly. Some ignitions have very slow curves that may require you to rev the engine to 5000 rpm
before it gets to full advance.
We do not recommend these
. Instead we prefer to select a point from the manufacturers’ advertised curve at
3000 to 3500 rpm max to
verify this type of curve
. This can give you an idea of how close the curve is to advertised data. On larger cubic inch
engines the total timing is very important to engine life and performance. If your ignition does not meet the advertised curve be very cautious
and replace or reset the part immediately.
Mark 3.
= (R) (NOTE 1) Advanced timing mark for Rear Cylinder. This mark is only a reference
and is rarely used
for ignition timing. Some
ignitions offer an adjustment for rear cylinder and front cylinder timing spreads where this mark can be useful. An example of
this is a Dyna S single fire ignition and Crane HI4. We recommend you verify the rear cylinder timing if using these ignitions.
