Default Re: holley cam sync

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Originally Posted by Holley Crank & Cam Sensor Setup
CRANK/CAM SENSOR INSTALLATION AND SETUP

The following information is used to assist with the proper installation and setup of various crank and cam sensors and hardware. Most of these settings are setup as a “Custom” ignition type in the software.

NOTE: You should have a balancer this is fully degreed or a timing tape installed on the balancer to perform the following settings.


1.0 CRANK SENSOR SETUP

1.1 Ignition Reference Setup – “one pulse per fire” trigger, Magnetic Pickup

The following shows how to set up the crank signal for a “one pulse per fire” RPM input using either a magnetic pickup crank trigger or distributor. A “one pulse per fire” trigger means there is one sensor pulse for every cylinder firing (on a V8 this would be a 4 pulse crank trigger or a 8 pulse trigger in the distributor).

Note: In the software, the Sensor Type should be set up as “Magnetic”.

  • Note the ignition reference angle set in the software. This is typically set to a value that is 10 more than the highest timing you will run. Do NOT set it higher than 75. 60 is a common value. 60 will be used for an example here.
  • Turn the engine over so that it is at the ignition reference angle. For this example it would be 60 degrees BTDC on cylinder #1. The timing pointer should be indicating 60 degrees BTDC on the crank.
  • Align/turn the crank trigger or distributor so that the sensor is perfectly inline with the trigger.

  • For a magnetic pickup crank trigger, this means the pickup and a magnet should be inline.
  • For a magnetic pickup distributor, this means having one of the reluctor teeth line up with the magnetic pickup.

  • Tighten everything up.
  • If you are not using a cam sync (if you are, continue to section 2.1), everything should be set close enough to start the engine. It is recommended that you disconnect the injectors and crank the engine over. Look at the timing with a timing light. It should be firing at the cranking timing value shown on the data monitor. If it is off a few degrees, you can move the pickup slightly, or change the Ignition Reference setting to sync things up. If you change the Ignition Reference value, note that you must cycle the ignition power for it to take affect.


1.2 Ignition Reference Setup – “one pulse per fire” trigger, Hall Effect Pickup

The following shows how to set up the crank signal for a “one pulse per fire” RPM input using either a hall effect pickup crank trigger or distributor. A “one pulse per fire” trigger means there is one sensor pulse for every cylinder firing (on a V8 this would be a 4 pulse crank trigger or a 8 pulse trigger in the distributor).

NOTE: In the software, the Sensor Type should be set up as “Digital Rising” or “Digital Falling”.

  • Note the ignition reference angle set in the software. This is typically set to a value that is 10 more than the highest timing you will run. Do NOT set it higher than 75. 60 is a common value. 60 will be used for an example here.
  • Turn the engine over so that it is at the ignition reference angle. For this example it would be 60 degrees BTDC on cylinder #1. The timing pointer should be indicating 60 degrees BTDC at the crank.
  • Align/turn the crank trigger or distributor so that the sensor is aligned properly. In the software, the signal should be set up as “Digital Rising” or “Digital Falling”. A hall effect sensor typically uses a “shutter window/wheel” that has “openings” and areas of material that are in close proximity to the sensor that triggers the sensor output. Or it uses a toothed wheel that has “teeth” and “gaps”.

When the sensor sees the edge of an “opening” or a “gap”, this triggers the sensor in a “Falling” manner. When the sensor sees the first edge of the material or tooth, this trigger the sensor in a “Rising” manner.

To set the hall effect pickup properly:

  • If set as “Digital Rising”, the pickup should be located such that the sensor is aligned where the shutter window/wheel or tooth edge first hits the center of the hall effect sensor.

  • If set as “Digital Falling”, the pickup should be located such that the sensor is aligned where the “opening” in the window/wheel is or the tooth gap starts (also meaning where the sensor leaves the edge of the shutter window/wheel or tooth edge).

  • Tighten everything up.
  • If you are not using a cam sync (if you are, continue to section 2.1), everything should be set close enough to start the engine. It is recommended that you disconnect the injectors and crank the engine over. Look at the timing with a timing light. It should be firing at the cranking timing value shown on the data monitor. If it is off a few degrees, you can move the pickup slightly, or change the Ignition Reference setting to sync things up. If you change the Ignition Reference value, note that you must cycle the ignition power for it to take affect.

1.3 60-2 Wheel

The following covers the installation of a 60-2 crank trigger wheel Holley offers. Holley offers kits for Small and Big Block Chevy engines to mount the sensor and wheel. Four different diameter 60-2 wheels are available that can be custom mounted on any engine.

The “60-2” alludes to the fact that crank trigger wheel has 58 teeth with “2 missing”. This is also known as a “58x” wheel. The “missing” teeth are used as an ident so that the ECU can recognize the exact angular position of the crankshaft. Having 58 teeth allows the ECU to much more precisely calculate engine speed compared to a trigger wheel with less teeth.

To set up a 60-2 wheel:

1. Rotate the engine to #1 TDC.

2. The software has a parameter called “TDC Tooth Number”. This is typically set to “10”. The example below will use 10 as this value. Do not set it below a value of 9 for best timing accuracy. Values higher are acceptable, but you need to make sure the cam sensor is installed appropriately if one is used (see section 2.2).

3. With the engine at TDC on #1 cylinder, the sensor will be positioned such that it is lined up with the “TDC Tooth Number” (for this example 10). This is the 10th tooth “after the missing teeth” on the crank trigger wheel in the direction that the engine rotates. Install the crank trigger wheel and align the bolt holes on it such that the sensor will be near this position.

Most all engines rotate clockwise, except for Honda engines which rotate counter-clockwise. If you are confused about which tooth this means, put the trigger wheel on the engine and rotate just the trigger wheel (leave the engine at TDC on #1) in the direction the engine rotates. Rotate it until the missing teeth/gap line up to where the sensor will be mounted, then continue turning it and count 10 teeth. Take a marker and mark this tooth. It will be the tooth you need to align with the sensor.



2.0 CAM SYNC POSITIONING

A cam sync pulse is required if you are running sequential fuel injection. This tells the ECU which cylinder is cylinder #1 (or the first cylinder in the firing order as entered in the software). The following describes setting this up for a “one pulse per fire” crank input as well as a “60-2” crank input.


2.1 Cam Sync setup when using a “one pulse per fire” crank input

For a "one pulse per fire crank” signal ( ie a 4 pulse crank trigger on a V8 ), the cam sync signal must occur in a specific range to properly ident which cylinder is cylinder #1. If this is not done properly, individual cylinder trims will not be performed on the correct cylinder, or worse, if using individual coils, the wrong cylinder will be fired, potentially damaging the started, flexplate, or worse.

The best way to determine the proper range is by using the following basic formula to determine the crank angle range that the cam ident can occur. An example is give afterwards along with a table that has certain combinations already calculated.

Cam sync location (degrees BTDC #1) = "Ignition Reference Angle" + “A” + (“A” / 2)
“Ignition Reference Angle” = Taken from Crank Sensor Setup in software
“A” = Angle Between Crank Pulses (crank degrees between triggers on the crank sensor)

“A” for a 8 cylinder = 90
“A” for a 6 cylinder = 120
“A” for a 4 cylinder = 180

Using the formula above, plug in the “Ignition Reference Angle” you are using and the proper “A” value depending on the number of engine cylinders. The location calculated is the “ideal” location and can vary +/- 30 degrees or possibly more. If you are out of this range contact Holley Tech Service for options.



Example - 8 cylinder with a Ignition Ref Angle of 60

Cam Sync Location = 60 + 90 + 90/2 = 195 degrees BTDC #1

Cam Sync Location = 60 + 90 + 45 = 195 degrees BTDC #1

195 would be the centrally "perfect" location for this specific example. However, this location can vary by +/- 30 degrees from this nominal target value with no issue.



Number of Cylinders Ignition Reference Angle Cam Trigger Location Range (BTDC #1)
4 60 330 +/-30 degrees
6 60 240 +/-30 degrees
8 60 195 +/-30 degrees

NOTE: If it is mechanically not possible to install the cam trigger in the proper location, the engine firing order can be changed to compensate.
For details on this, contact Holley Tech Service at 1-866-GOHOLLEY.

2.2 60-2 Cam Sync when using a 60-2 crank input

When using a 60-2 crank sensor wheel, this cam sync signal trigger MUST occur:

· Before cylinder #1 is at TDC on the COMPRESSION STROKE, make sure that it is not occurring on the exhaust stroke.

· It also MUST occur at least 8 teeth (approximately 50 degrees) before the “missing teeth” are read by the crank position sensor. If the crank sensor is set up such that the 10th tooth after the missing teeth is at TDC, position the cam sensor such that it is between 110 -250 degrees before TDC on cylinder #1. This will create a proper position.

This cam sync input can be configured as a magnetic or hall effect (digital rising or digital falling) input in the software. Make sure that if you are using a hall effect sensor, you have this set up properly as a rising or falling signal.

3.0 Crank & Cam Sensor Diagnostics

One of the most frustrating problems that can occur with EFI is crank and cam sensor signal issues. In order for an EFI system to operate properly, it must get proper crank and cam sensor signals. If there is a crank or cam signal issue, such as missing or extra pulses, the Holley EFI systems will show this on a datalog. If you feel that you are experiencing a crank or cam sensor problem, take an internal datalog at 100 samples per second of the problem. Add the “Diag #1” parameter to one of the datalog views and review it in the problem area. Look at the “ones” and “tens” positions of the “Diag #1” parameter. Once the engine is running, these positions should NEVER increment. If they do, it signals a crank or cam sensor signal problem. If you need help diagnosing this, it is recommended that you contact Holley Technical Support at 1-866-GOHOLLEY.
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