Alternator Driven Tachometer

Discussion in 'Tech/Mech General' started by DJK, Nov 29, 2015.

  1. DJK

    DJK

    Joined:
    Jul 29, 2015
    Messages:
    63
    Likes Received:
    21
    Location:
    Bury Lancashire
    Alternator Driven Tachometer

    My Fiat 2.9TDi 1999 is without an tachometer anyone every fitted one driven by alternator.


    I thought this would be the easiest way of fitting one.


    Secondly Anyone recommend a good Sparkie in Bury BL 8 Lancashire conversant with Motorhomes
     
  2. Reallyretired

    Reallyretired Funster

    Joined:
    Apr 27, 2008
    Messages:
    5,925
    Likes Received:
    3,391
    Location:
    Eastbourne East Sussex
    Fitted an accessory tacho back in the 70s, but that worked through the contact breaker (remember them?)
     
    • Like it Like it x 2
  3. Flamenca

    Flamenca Funster Life Member

    Joined:
    Jun 21, 2013
    Messages:
    791
    Likes Received:
    483
    Location:
    West Country and France/Spain
    Yes, I fitted one to my Ford escort in 1972 (y)
     
  4. Badknee

    Badknee Funster

    Joined:
    Aug 25, 2014
    Messages:
    3,782
    Likes Received:
    16,780
    Location:
    notloB
    Jeffs auto electrician. 30-36 Bury Old Rd. Bolton. BL2 2BZ
    01204 394582.
    Fixed my leccy window a treat. (y)
     
    • Like it Like it x 1
  5. mitzimad

    mitzimad Funster

    Joined:
    Jan 28, 2008
    Messages:
    3,206
    Likes Received:
    3,615
    Location:
    walthamstow east london
    i doubt you would find an altrnator driven one now early sprites and midgets had dynamo ones
     
  6. Lenny HB

    Lenny HB Funster

    Joined:
    Oct 18, 2007
    Messages:
    6,473
    Likes Received:
    6,472
    Location:
    West Sussex
    Fitted a taco to a new then 1974 Datsun Cherry, I think it was an induction pick-up from the 12v side of the coil.
     
  7. C200JK

    C200JK Read Only Funster

    Joined:
    Dec 27, 2014
    Messages:
    963
    Likes Received:
    3,174
    Location:
    Ireland / London
    Yes, can be done.
    Tiny-Tac do one that has a clamp you put around the injector pipe and has a sensor in it for the pulses.... Trouble is its a digital LED clock, not a sweep gauge. About $70 US.... Available via e-Bay.
     
    • Like it Like it x 1
  8. tonyidle

    tonyidle Funster

    Joined:
    Aug 6, 2013
    Messages:
    3,174
    Likes Received:
    3,012
    Location:
    Kendal, Cumbria
    Alternator drive as an aftermarket fit would be difficult. They pick up a pulse from the alternator windings but are designed to account for the alternator / engine pulley sizes which vary from one manufacturer to the next. The injector type mentioned by Jonkil would be easiest.
     
  9. Flamenca

    Flamenca Funster Life Member

    Joined:
    Jun 21, 2013
    Messages:
    791
    Likes Received:
    483
    Location:
    West Country and France/Spain
    • Like it Like it x 1
  10. Lenny HB

    Lenny HB Funster

    Joined:
    Oct 18, 2007
    Messages:
    6,473
    Likes Received:
    6,472
    Location:
    West Sussex
    Me being dumb of course no coil on a diesel
     
  11. Jaws

    Jaws Funster Life Member

    Joined:
    Sep 26, 2008
    Messages:
    18,668
    Likes Received:
    23,036
    Location:
    Narrfoook
    Fitted one for someone earlier this year..
    I honestly did not think it would work but it did and still does !
    I did wonder where it came from .. Chap told me 'a mate gave it to me' and when I searched at the time could not find any info at all
     
    • Like it Like it x 1
  12. Flamenca

    Flamenca Funster Life Member

    Joined:
    Jun 21, 2013
    Messages:
    791
    Likes Received:
    483
    Location:
    West Country and France/Spain
    @Jaws do you recall which engine you fitted the tacho on?
     
  13. Jaws

    Jaws Funster Life Member

    Joined:
    Sep 26, 2008
    Messages:
    18,668
    Likes Received:
    23,036
    Location:
    Narrfoook
    Yes mate. It was on an early 80's 2 litre ( might have been a 2.2 ) Ducato lump
     
    • Like it Like it x 1
  14. Peter A Forbes

    Peter A Forbes Funster

    Joined:
    Nov 23, 2014
    Messages:
    262
    Likes Received:
    182
    Location:
    Rushden, Northants, UK
    Most of the accessory rev-counters pick up their signal from the WL terminal on the alternator, this is rectified but unsmoothed DC which has enough AC content to run a tachometer.

    Discovery 1's use this system, Discovery 2's use the engine management flywheel speed sensor to get the engine speed signal from, via the ECU.

    If you're fitting an accessory electronic tachometer you will need to calibrate it against a known good mechanical tachometer like the Smiths Industries hand-held type.

    Diesel pulse tacho's are quite good and no electrics other than the 12V supply.

    Lots of other ways of doing it, we have fitted magnetic pickups to flywheel housings, getting the signal from the flywheel starter ring gear teeth going past the end of the magnetic pickup, have also used timing gears and even a toothed belt cog to get speed signals.

    Peter
     
    • Like it Like it x 1
  15. DJK

    DJK

    Joined:
    Jul 29, 2015
    Messages:
    63
    Likes Received:
    21
    Location:
    Bury Lancashire
    Thanks for the replies Folks, with exception to a couple Would a TDI (Turbo Diesel Injection) have a distributor Lol

    Anyone any idea on any cost please
     
  16. pappajohn

    pappajohn Funster Life Member

    Joined:
    Aug 26, 2007
    Messages:
    30,087
    Likes Received:
    17,751
    Location:
    YO11 2BD
    Seriously, Yes it does........

    Its called a mechanical high pressure injection pump.
    It DISTRIBUTES the incoming fuel to each injector in turn.....hence, a distributor.
     
  17. DJK

    DJK

    Joined:
    Jul 29, 2015
    Messages:
    63
    Likes Received:
    21
    Location:
    Bury Lancashire
    Well Pappajohn
    You have just learned me something I've been connected with Lorries, engines and FLT's all my working life and I'm in my 70'th year now and never have I heard an diesel injector pump be called a distributer I've heard it called many many names Not printable on this page when it won't bleed but never a distributer.
    The pinto engine in my Sports Cars got one but that's a 2 litre "Petrol"
    Good Night my friend I'm now going to bed smiling
     
    • Like it Like it x 1
  18. DJK

    DJK

    Joined:
    Jul 29, 2015
    Messages:
    63
    Likes Received:
    21
    Location:
    Bury Lancashire
    Badknee have you got a VW MH if so is that you on Google parked outside his place
     
  19. DJK

    DJK

    Joined:
    Jul 29, 2015
    Messages:
    63
    Likes Received:
    21
    Location:
    Bury Lancashire
    Badknee is this your VW MH parked outside
     

    Attached Files:

  20. Badknee

    Badknee Funster

    Joined:
    Aug 25, 2014
    Messages:
    3,782
    Likes Received:
    16,780
    Location:
    notloB
    No it's not me, Google hadn't been invented when I had my VW type 2 bay window.
     
Loading...

Share This Page