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Thread: Timing 3.5 V8 1987 4CU

  1. #1
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    Timing 3.5 V8 1987 4CU

    Can anyone help : - I've had my timing set by my mechanic at 15 degrees advance - he's claimed theres about 40 degrees stretch in the timing chain so this is him "giving it a chance" he set this on petrol ( car has multipoint LPG also landirezo system was told its from Deakin Automotive) with the revs at about 1050 and with out taking the pipe off the mechanical vacuum advance. I asked him how many is the maximum degrees advance, he said I don't know.

    Car runs like **** cold now and doesn't sound right when its warmed up and is down on power.

    I've read manuals that say to set at -1 and read posts that say -6 to -8, some posts I've read have gone as far as -12. I haven't seen -15.

    Where should I be setting the timing?

  2. #2
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    On petrol 10-12 is pretty good start. Not so sure on gas. Why not try itís pretty easy to do if you have a timing light

  3. #3
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    Just loosen the dizzie off and back it off a tiny bit at a time until it runs the best. Exact timing doesn't really matter IMO ... set it to its sweet spot (this is how I set my old cars).

    seeya,
    Shane L.
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  4. #4
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    I would just start by setting it so it idles smoothest, then advance it by a bit then go for a drive. Keep repeating the advance until it pings on acceleration, then back it off a bit to stop the pinging. Presto, optimal timing...
    Chris


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  5. #5
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    The standard setting is 3 BTDC - with my 3.5 on dial fuel I had the timing set at 10 BTDC (static) and on petrol and LPG is ran great - no noticeable change of power when switching between the fuels - so going 10 BTDC is a good start on 91 unleaded - but listen for pinging to be sure.
    REMLR 243

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  6. #6
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    thanks for your help fellas

  7. #7
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    40 degrees of stretch?

    the valve timing would be so far out of spec I'd be amazed if you got it to do more than idle, assuming you could get it to start because with that much strecth it'd be hitting the pot so far back in the timing it might as well be out of phase by a pot.

    the math on it (depending on how you measure the cam angle) says that with 40 degress of stretch (measured at the crank angle marker) with the dizzy timed to the cam for 10 degrees BTDC youd be hitting at 30 degrees ATDC. OR roughly 1/4 of the way into your effective power stroke, torque would be so far down youd be forgiven for thinking it was a rotary.

    lets say you worked it the other way and had the dizzy sorted to fire at the right place on the crank, the cam would now be so far advanced you'd be trying to fire at 50 degrees BTDC, thats about a third of your compression stroke to early.

    I'm not even going to guess at fuel economy.

    but...

    LPG is a lighter burning fuel, and it will handle a bit more advance than the ULP. depending on which fuel you run (Premium or E85) take near enough the same advance as LPG.
    Dave

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  8. #8
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    What are the chances this "specialist land rover range rover mechanic" has no idea what he is talking about with the timing?

    He thought the sensor for the 9th injector was the coolant temp sensor, took the lid off the AFM and told me not to bother sealing it back up as "they don't fall off anyway" and adjusted the spring by hand without any testing machinery to dial it in, and adjusted the throttle position sensor without using a multimeter, just unscrewed it and wiggled it a bit then nipped it back up. Oh and he left the distributor loose enough to be easily rotated by hand and for the engine to rotate it while running. By the way his business is recommended on this site regularly however it looks like he bought it a year or so ago and the mechanics that gave it a good name are long gone and when this bloke took over he ended the businesses association with the VACC

  9. #9
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    Quote Originally Posted by DoubleChevron View Post
    Just loosen the dizzie off and back it off a tiny bit at a time until it runs the best. Exact timing doesn't really matter IMO ... set it to its sweet spot (this is how I set my old cars).

    seeya,
    Shane L.
    Exactly how I do my 2 as well - backwards and forwards a bit until I find where it runs sweetest. I did check one once and I know the 101 is running at 12. Was running more than that when I got it, but had pre ignition issues when hot up further.


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  10. #10
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    Quote Originally Posted by RRC James View Post
    What are the chances this "specialist land rover range rover mechanic" has no idea what he is talking about with the timing?
    oh you went there.....

    pretty good...

    Want the details of a guy I know who can probably put some pointers on for you?
    Dave

    "In a Landrover the other vehicle is your crumple zone."

    For spelling call Rogets, for mechanicing call me.

    Fozzy, 2.25D SIII Ex DCA Ute
    TDI D1(parting/ed)
    Tdi autoManual d1 (Kept it for the girlfriend)
    Archaeopteryx 1990 6x6 dual cab(This things staying)


    If you've benefited from one or more of my posts please remember, your taxes paid for my skill sets, I'm just trying to make sure you get your monies worth.
    If you think you're in front on the deal, pay it forwards.

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