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Geocritter's avatar
Geocritter
Explorer
Aug 24, 2013

Big block V8’s and premium gasoline

Has anyone here bumped the timing on their Ford 460 V8 for better performance? I realize that doing so probably necessitates the use of higher octane gasoline, but is the added performance and potential fuel mileage gain worth it? If so what was the timing changed to?

I only ask this question because of my experience with a 1989 Jeep Cherokee my son once owned. The straight 6cyl 4.0 engine was equipped with an anti-knock sensor that automatically retarded the spark. It worked but retarding the spark had a terrible effect on both the cars performance and gas mileage. For example you were normally hard pressed to average 20mpg range highway (the car had a 5-speed standard with a 3.07 axle ratio, not the normal 3.58 axle ratio). On a trip to college, towing a twin axle U-Haul trailer using premium gasoline the car got 25mpg!

Steve
Class A
  • wny_pat1's avatar
    wny_pat1
    Explorer
    Aug 25, 2013
    I had a 460 in a Ford LTD many years ago. Could not run it on regular gas cause it would ping like mad. It called for premium if I remember right. I got it down to where I was blending a gallon of premium with each fill up. Then she would run really good and not ping. Just offering my experience with a 1980s Ford 460 engine. I played with timing but could never get it right like what that gallon of premium did.
  • down_home's avatar
    down_home
    Explorer II
    Aug 25, 2013
    Advance the cam timing to +4 degrees with new timing gear chain set and offset keys or the timing gear sets with different slots for the key. .
    Advance the ignition timing until you start to hear detonation and back off 2 degrees and use 93 octane not 91 octane all the time. The low compression of your 460 will not probably detonate until about 14 degrees initially if then. Have the distributor curved. there are still shops that do that since most hot rod engines are old iron. They can cure so that total ignition timing won't make it knock. They can retard timing as engine rpm goes up too.
  • Deano56's avatar
    Deano56
    Explorer
    Aug 25, 2013
    any older vehicle with a distributor will have performance gains by advancing the timing and adding premium fuel, how much more power?? My supercharged Bonneville gains 5hp per degree advanced, but that's all electronic controlled. I remember years back we would advance the timing until the engine would ping/knock with our foot on the brake and pressing on the accelerator pedal. I couldn't see the fuel economy being enhanced while under load though
  • RLS7201's avatar
    RLS7201
    Explorer II
    Aug 25, 2013
    Lipets wrote:
    RLS7201 wrote:
    Several of us in the Ford EFI 460 community have been able to run our initial timing @ 12 degrees, with no pinging issues. Another option is to lengthen the rod on the EGR feed back potentiometer, until you get 0.85 volts, at idle, on the out put lead. This will boost the timing a little more when the EGR valve opens.

    Richard


    And what exactly will that result in?


    This will give the engine a touch more torque and HP. NO, this will NOT increase fuel mileage. Saying fuel mileage and 460 in the same sentence is just silly.

    Richard
    95 Bounder 460 w/banks
    TDY: Yukon Territory, CA
  • greginsp's avatar
    greginsp
    Explorer
    Aug 24, 2013
    In my opinion, all of the replies point to the difficulty of getting any significant additional power easily out of a factory motor for heavy towing.
    Most of the gasoline motors designed for medium duty trucks(2 to 2 1/2 ton trucks in dump trucks etc.)that I remember were all low speed motors with thick piston tops, long strokes and light fueling (small carbs and intake runners). They were designed to run at their peak rpms for long periods. They all used regular fuel as well.
  • Geocritter's avatar
    Geocritter
    Explorer
    Aug 24, 2013
    This board has been so very helpful with past questions I've had and I'd like to say thanks. Today I'm afraid I'm a little grumpy, I hope I haven't offended anyone.
    Steve
  • 427435's avatar
    427435
    Explorer
    Aug 24, 2013
    While increased octane may allow some advancing of the timing, it will not greatly affect power (if at all). To gain benefits from higher octane fuel, you need higher compression.
  • noteven's avatar
    noteven
    Explorer III
    Aug 24, 2013
    I take owner's manual recommendations to use "minimum 85 octane gasoline or gasohol" to mean "minimum", or "will run on it", not "designed for".

    Every knock-sensor equipped engine I have owned: GM Vortec, GM LT1, Toyota, Nissan will return slighty better fuel economy on premium gasoline vs regular often easily covering the cost difference per gallon. The GM V8's were used for towing and were much happier on premium.

    When today's 85 octane rated gasohol absorbs some water in vehicles that stand unused you lose the octane benefit of the ethanol so the gasohol is no longer 85 octane.

    A modern tuner designed for the 460 if there is one plus some premium gas might give good results.

    You can start by trying some of the simple tips plus using premium fuel to compare performance.
  • Geocritter's avatar
    Geocritter
    Explorer
    Aug 24, 2013
    traveylin wrote:
    The Ford v-10 works well on regular and provides adaquate output with out tinkering
    But that doesn't help me much does it, or are you suggesting I swap out my 460 V8 for a V10.
    Steve

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