Setting New Timing, Or Not?

Discussion in 'Fox 5.0 Mustang Tech' started by gsnort, May 13, 2014.

  1. I have upgraded my ’89 LX hatchback street/strip with a Dart 347 stroker, forged crank with forged aluminum pistons topped off with aluminum 170 Trick Flow Twisted Wedge heads w/ 61cc chambers and Lunati aluminum rocker arms. I’ve changed from stock to a Ford F-303 camshaft. I have kept the old 65mm throttle body and 30 lb. injectors. Okay, what do I do about the timing? I think I’d have to change that by first unhooking the computer. If I'm correct or not, what are your specific suggestions?
  2. You can leave the computer hooked up... Ignition timing, or cam timing?

    Edit: To do the ignition timing, you first disconnect the computer, then start the car and let it warm up. Then, while the car is running with no computer you pull the spout connector, loosen the distributor hold down bolt, and turn the dis until you're at 10 BTDC. Then hook up the computer and let her ripppp. :)
  3. Whats this disconnect the computer crap? :shrug:
  4. Its a joke, with poor delivery.
    1. Heres a writeup compliments of stangnet member @jrichker

    2. Paint the mark on the harmonic balancer with paint -choose 10 degrees BTC or 14 degrees BTC or something else if you have NO2 or other power adder. I try to paint TDC red, 10 degrees BTC white, and 14 degrees BTC blue.

      Remove the SPOUT connector (do a search if you want a picture of the SPOUT connector) It is the 2 pin rectangular plug on the distributor wiring harness. Only the EFI Mustang engines have a SPOUT. If yours is not EFI, check for a SPOUT: if you don’t find one, skip any instructions regarding the SPOUT
      Warning: there are only two places the SPOUT should be when you time the engine. The first place is in your pocket while you are setting the timing and the second is back in the harness when you finish. The little bugger is too easy to lose and too hard to find a replacement.

      Connect timing light up to battery & #1 spark plug.
      To time the ignition: remove the SPOUT and use the timing light to check the timing against the marks on the harmonic balancer. Loosen the distributor hold down bolt and turn the distributor slowly until the light and the desired mark on the harmonic balancer line up. Tighten down the distributor hold down bolt and re-install the SPOUT jumper. When you put the SPOUT back in the computer will advance the spark. The timing may move around some with the SPOUT installed.

      10 degrees BTC is towards the drivers side marks.

      Simplified diagram of what it looks like. Not all the marks are shown for ease of viewing.

      ATC ' ' ' ' ' ' ' ' ' '!' ' ' ' ' ' ' ' ' ' BTC
      ---------------- > Direction of Rotation as viewed standing in front of the engine.

      The ' is 2 degrees.
      The ! is TDC
      The ' is 10 degrees BTC
      Set the timing 5 marks BTC. Or if you prefer, 5 marks towards the driver's side.

      The HO firing order is 1-3-7-2-6-5-4-8.
      Non HO firing order is 1-5-4-2-6-3-7-8


  5. :loser:
  6. seems 12* - 14* is the avg advance, yours may like a tad more or less
  8. Thanks for the help. It is much appreciated. I wasn't being facetious about disconnecting the vehicle's computer. A local fender lizard said I'd have to disconnect or the computer would force the timing to return to its original, default timing.
  9. Thats what pulling the spout connector does
  10. Tell that nutwsinger to go change the muffler bearing
  11. Well, my understanding is you are partially correct. Once you drive for a while the computer stores the parameters. Disconnecting your computer for 20 mins will erase the eprom.

    What I noticed on my computer, I don't know if this is true for all of them, if the car is turned off for a long period of time it resets on its own. I'm not sure if its a partial reset or full param reset? Thats my understanding and observation, but I'm sure someone who knows more than me can give a better description.

    Edit, the comp does control timing curves. I've read at WOT the comp is setting around 18 - 20 deg advanced, depending on which comp.

    PS- just being a d*ck, nothing personal.