Jump to content
John Appel

Crank tooth and sync tooth separation

Recommended Posts

I have a Link G4 Storm. I believe that the signal from the crank reference tooth  and the cam sync tooth must not coincide. What would be the minimum separation required in crank degrees.What would be the result if they were too close.

Share this post


Link to post
Share on other sites

Hi John, 

If you are talking a crank wheel with evenly spaced teeth (i.e no missing teeth) then cam tooth position is quite important.  With a missing tooth crank wheel it is not important.

For multitooth mode our official recommendation is to have the cam tooth centred within the 50% green window (pic below), however that is probably to allow some reasonable margin of safety due to backlash in the cam drive system etc.  It will still work much closer than that as long as the cam tooth always stays on the "same side" of the crank tooth - if it crosses over then the ecu will lose position and your timing will possibly be out by one tooth for the next cycle.

ZlG0OeP.png

 

Share this post


Link to post
Share on other sites

Thanks for that Adam. My crank trigger is 24 - 2  so you are saying that it does not really matter where the cam tooth occurs.  I have been told that the Link only needs the cam tooth on the first rotation of the camshaft at startup. Once the cam tooth has gone past the sensor once the engine is synchronised and will stay that way. In other words it does not have to reset itself for every engine cycle and even if you disconnected the sensor wire the engine would keep running.   Is this correct.

Share this post


Link to post
Share on other sites

Correct, it is far less important with a missing tooth crank.  All the ECU looks for is whether a cam pulse occured in the last revolution or not.  There is still some basic rules for best practice, shown in the picture below (note the picture in the current help file is wrong).  Basically you dont want the cam tooth to occur too close to the crank tooth after the missing teeth as this is when it does its "sync test".

 

1 hour ago, John Appel said:

I have been told that the Link only needs the cam tooth on the first rotation of the camshaft at startup. Once the cam tooth has gone past the sensor once the engine is synchronised and will stay that way. In other words it does not have to reset itself for every engine cycle and even if you disconnected the sensor wire the engine would keep running.   Is this correct.

Sort of, but not entirely correct.  The ecu will constantly check the cam to confirm sync.  However, it is smart enough that it can keep in sync once running even if you disconnect the cam sensor.  

 

C5dg3Wx.png

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

×
×
  • Create New...