Page 1 of 2 12 LastLast
Results 1 to 10 of 13

Thread: Crank/Cam Trigger questions

  1. #1
    New Member
    Join Date
    Oct 2012
    Posts
    6

    Default Crank/Cam Trigger questions

    Ok I'm really interested in putting a GM computer on my Volvo 4 cylinder turbo project. The thing I'm worried about is crank/cam triggering. Now we have a few options, the first and what I think would work the best is this.
    http://yoshifab.com/store/index.php?...d&productId=45
    That allows us to run a DSM/Mitsu CAS which incorporates a crank and cam sensor into one item. Then we have this.
    http://yoshifab.com/store/index.php?...d&productId=46
    That converts the sensor to 24 and 1. The question is will a GM Computer read that? I'm willing to spend the money on the adapter and disk, I'm just worried about spending $900 on EFI Live if I can't make it work. I've tried doing a lot of searching and haven't found anything really definitive about using aftermarket triggers and what not.

  2. #2
    Joe (Moderator) joecar's Avatar
    Join Date
    Apr 2003
    Posts
    27,808

    Default

    Those will not work with the GM PCM...



    The LS1 24x reluctor wheel is actually a pair 24x encoded inverse image reluctor wheels...

    ( there are 2 different tooth dimensions, the sequence of the tooth dimensions encodes the crank position )

    ( each wheel is the inverse image of the other )

    in the attached image look closely at edge of the wheel, you will see 2 wheels with varying tooth widths...

    the LS1 PCM looks specifically for the encoded pattern

    ( image borrowed from ls1tech.com )



    Click image for larger version. 

Name:	24x reluctor.png 
Views:	588 
Size:	424.7 KB 
ID:	14031

  3. #3
    Joe (Moderator) joecar's Avatar
    Join Date
    Apr 2003
    Posts
    27,808

    Default

    The GM 4 cylinder engines use a different reluctor wheel than that and an ECU to match.

  4. #4
    New Member
    Join Date
    Oct 2012
    Posts
    6

    Default

    Another Option I have is, my car comes factory with a 58X crank trigger on the flywheel, I just figured the 24x would be easier but didn't realize the trigger was a weird pattern. If I was to use the 58X I'd just have to make a cam trigger, the question is will the GM computers respond to a generic sensor or will they only read the factory ones?

  5. #5
    Joe (Moderator) joecar's Avatar
    Join Date
    Apr 2003
    Posts
    27,808

    Default

    The 58x crank reluctor is really 60x-2 (i.e. 60x minus 2 teeth).

    The ECM that uses this 58x crank reluctor also uses a 4x asymmetrical cam reluctor.

    The generic sensors may or may not work.

  6. #6
    New Member
    Join Date
    Oct 2012
    Posts
    6

    Default

    Yah thats exactly what they have on the flywheel 60-2.

  7. #7
    New Member
    Join Date
    Oct 2012
    Posts
    6

    Default

    Wanted to update this, i've been tinkering with this idea still and this is what I have come up with so far. Keep in mind this is a crude drawing and what not.

    Click image for larger version. 

Name:	391368_10151661209786982_7922107_n.jpg 
Views:	992 
Size:	47.9 KB 
ID:	14432

  8. #8
    Lifetime Member EagleMark's Avatar
    Join Date
    Dec 2010
    Posts
    466

    Default

    That looks like a shutter wheel from an LT1 distributor or the aftermarket distributor for a 0411 swap. Is this what your trying to do?

    Click image for larger version. 

Name:	411-distributor.jpg 
Views:	524 
Size:	45.6 KB 
ID:	14433

  9. #9
    New Member
    Join Date
    Oct 2012
    Posts
    6

    Default

    I'm trying to install a GM Computer (E67 preferably) on my 4 cylinder volvo, I have an adapter that uses a Diamond Star Motors CAS(Crank Angle Sensor) which has the crank and cam sensor built into one deal. But that appears to be a similar concept as to whats going on there.

  10. #10
    Joe (Moderator) joecar's Avatar
    Join Date
    Apr 2003
    Posts
    27,808

    Default

    That will not work because the cam 4x sequence (i.e. the cam sprocket and distributor) spins at half crank speed.

Page 1 of 2 12 LastLast

Similar Threads

  1. cam/crank correlation with vortec dist?
    By Aloicious in forum Conversions / Aftermarket Parts
    Replies: 14
    Last Post: November 15th, 2017, 12:37 PM
  2. Replies: 83
    Last Post: September 26th, 2015, 01:18 PM
  3. Grid heater trigger-temperature
    By MQ105 in forum Cummins 5.9L
    Replies: 3
    Last Post: June 12th, 2011, 03:21 PM
  4. Can someone verify this layout of the 4x cam trigger wheel?
    By tunedportcj5 in forum E37, E38 & E67 PFI ECM's
    Replies: 4
    Last Post: March 10th, 2011, 12:19 AM
  5. Tuning questions w/cam/header mods..
    By Redline Motorsports in forum General (Petrol, Gas, Ethanol)
    Replies: 15
    Last Post: October 25th, 2005, 10:36 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •