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Type 1 Crank Trigger

Machining Pulley Assembly Hardware Install Sensor Wiring Software Setup


Here is the procedure to machine your own pulley, if you choose to do it yourself. The overall process is the same for both aluminum and steel pulleys. If it looks to intimidating you can always send it in for us to complete for you.

Tools you'll need:
9" Lathe - Or a friend with one.. 
8" calipers
Dial test indicator
2 x Mag Base for X and Y
2" dial indicator (optional for cut depth)
1" dial indicator 
1-2-3 blocks
Pencil / Pen
Some paper
About an hour



Pulley Assembly 

Click on your pulley type below, or scroll down to the appropriate section:

Aluminum Pulley

Tools you'll need:
Drill Press
#4-40 Tap and #43 Pilot Drill
7/64" Drill Bit
#4 Countersink
Blue Loctite
30-45 minutes

 Steel Pulley

Tools you'll need: Die Grinder w/ 1/4" burr, Calipers, Sharpie and Tig Welder

Once you mark the pulley and the trigger wheel, install the wheel by lining up the marks.


The next step is to mark the pulley at 45 degree increments around the pulley.


Clamp the pulley/trigger wheel combo to the bench and get ready to weld.


Hardware Installation

On a Type 1 engine, the crank sensor will be placed behind the pulley to the right of the oil pump attached to the case bolt. You must put a hole in the Tin for the sensor to poke through.

With some aftermarket Crankcase's the bracket will need to be clearances for proper fitment. Optionally an additional washer could be placed under the bracket to bring it off the case slightly. The brackets are designed to have enough adjustability to compensate for this. You may mount the sensor on the front or back side of the mounting bracket. This is to allow for almost any case/pulley combo. 

If you are installing a Bergmann pulley combo, the sensor itself may need to be trimmed slightly to sit tightly against the case. Usually less than 1/8". 

When using a Dry Sump pulley, the trigger wheel must be machined for at least 1/2 the thickness of the trigger wheel to prevent clearance issues with the oil pump. You may need to add pulley spacers to gain this clearance. Once you install your new pulley be sure to check the belt alignment and shim the pulley and or alternator pulley to prevent abnormal wear.

-- Here are some basic illustrations with the sensor bracket location and tin modification needed --

Trigger Wheel Placement Rev3

VR sensor and bracket mounted to case VR sensor mounted showing clearance to pulley Tin trimmed for VR sensor to protrude


-- Template and instructions to drill your pulley tin --

* Print this template *


Mount sensor


Print template


Cut out template


Fold template in half


Place template and tape back backside


Now tape front side


Prepare for 1/8" pilot hole


Pilot hole drilled


Enlarge Pilot with hole-saw or Uni-bit


Place tin to check fitment

You will want to keep the hole

slightly oversize to allow

for sensor adjustment when

the pulley is installed


Indexing Your Trigger Wheel

With dozens of pulley options, multiple trigger wheel sizes and different crank sensor brackets, there are multiple options for installing the trigger wheel.

The 42.5 Degree angle referred to in the illustration above represents the missing tooth position BBDC (Before Bottom Dead Center). While viewing the pulley from the front this is at the 6-9 o'clock position and from the back the 3-6 o'clock position. My standard pulley is a CB Performance Santana Pulley. They are a high quality part with engraved timing marks. Pulleys with silk screened timing marks tend to rub off in a short period of time. 90 degrees is a standard sensor to missing tooth offset between ECU manufacturers. This puts the sensor at position "X" and the missing tooth 90 degrees ahead of it. The next tooth on the trigger wheel is the #1 tooth. This is known as the #1 tooth angle. Making my standard #1 tooth angle 80 degrees with a rising edge trigger.

42.5° BBDC - 6.5 - 7" Pulleys
35.5° BBDC - Power Pulleys
32.5° BBDC - Dry Sump or Bergmann Pulleys

Typical Sensor Gap - .030" 

CB Performance products specifically the preferred #1 tooth angle is 70 degrees instead of 80. This moves the missing tooth 10 degrees closer to BDC on the pulley. So when using a CB Performance controller you will use the following missing tooth position.

32.5° BBDC - 6.5 - 7" Pulleys
25.5° BBDC - Power Pulleys
22.5° BBDC - Dry Sump or Bergmann Pulleys

Typical Sensor Gap - .030"

Sensor Wiring

MS2 Sensor Wiring
Sensor / ECU
Red - VR+
Green - VR-
Black - Shield
Sensor / ECU
Red to VR-
Green to VR+
Black - Shield (can be left open/disconnected)
10k shunt resistor added across VR+/VR-
CB Performance Magna Products
Sensor / ECU
Red to VR- (Black)
Green to VR+ (Clear or White)
Black - Shield (can be left open/disconnected)
Fuel Tech 450/550

Sensor / ECU
Red to Signal (Red) Connector A Pin 19
Green to Reference (White) Connector A Pin 18
Black - Shield (over braid) Connector A Pin 18 (can be left open/disconnected)

Fuel Tech 600

Sensor / ECU
Red to Signal (Red) Connector B Pin 1
Green to Reference (White) Connector B Pin 2
Black - Shield (over braid) Connector B Pin 2 (can be left open/disconnected)


Software Settings

For Megasquirt 2, Megasquirt 3, and Microsquirt installations use these base ignition settings with my crank trigger packages:
#1 Tooth Angle 80°
Rising Edge

Once the installation is complete you will want to verify timing with a timing light. If the computer readout does not match the timing light adjust the #1 tooth angle to get the two to match. This is very important.