Fuel Foam | FerrariChat
Buy

Fuel Foam

Discussion in '365 GT4 2+2/400/412' started by Highmiler, Jul 17, 2011.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, Skimlinks, and others.

  1. Highmiler

    Highmiler Formula Junior

    Dec 8, 2010
    414
    Missouri
    Full Name:
    Greg
    #1 Highmiler, Jul 17, 2011
    Last edited: Jul 17, 2011
    When returning from a 1236 mile, three day turn around from Mid Missouri to Minneapolis, Minnesota we hit Kansas City on a Saturday afternoon. Heading east out of KC in the 400i we ran into a long stretch of construction. The freeway was reduced to 2 lanes and confined by those concrete temporary dividers. I thought I could feel a miss in the engine but it was very faint. After 10 miles of this it was time to switch drivers anyhow so I exited the freeway.

    At the bottom of the ramp the engine quit but restarted with a little throttle. Then it quit again and restarted by pumping the throttle a little. I'd been running 87 octane unleaded and decided to put in 91 octane to see if it helped. It didn't.

    As we neared home, 150 miles later, the engine missed regularly between 1000 and 2000 RPM. The harder the acceleration the worse the miss. At more than 2000 the miss disappeared, or seemd to. Once I'd unloaded the luggage I pulled the car onto my lift. Inside the garage the fuel pumps sounded like boxes of rocks being shaken.

    My buddy in Minnesota suggested letting the car sit overnight to cool off. Today everything works just fine again. The reason for telling this long story is this: ethanol. We in the US are blessed with ethanol in our fuels and this stuff boils at a rather lower temperature than good ol' leaded gas.

    So what I had was similar to vapor lock. Apparently the ethanol boils and causes the fuel to turn to foam which goes merrily through the system and ends up as a miss fire.

    The temp was 95 F and very humid. The water and oil temp never moved and the oil pressure was normal. Traffic was slowed to @ 45 MPH.

    For what it is worth to know,

    Greg
     
  2. Fritz Ficke

    Fritz Ficke Formula 3
    Rossa Subscribed

    Jan 3, 2006
    2,266
    Tucson, AZ.
    Full Name:
    Fritz Ficke
    #2 Fritz Ficke, Jul 17, 2011
    Thanks, good info.
     
  3. 166&456

    166&456 Formula 3

    Jul 13, 2010
    1,723
    Amsterdam
    #3 166&456, Jul 18, 2011
    Last edited: Jul 18, 2011
    I believe some V12's that were destined for warmer climates have a fuel cooling system that works on the A/C system for this very reason. I know for sure that it has been used on some 456M's but possibly others, too. An interesting solution but it works.
    Perhaps Ferrari should have isolated the fuel tanks and piping more.
    This happens to more V12 cars btw, Jaguar V12s such as some XJS's and XJ12's had issues with fuel boiling in the tanks as well.

    Yours doesn't sound as extreme as that, the fuel pumps were probably making vacuum bubbles (or alcohol vapor bubbles?) at their intakes. I can think of solutions to fix that (prepumps and swirl pots, etc) but that would require a fair bit of engineering. I guess more modern cars with fuel pumps in the tank have less of an issue with this.
     
  4. SouthJersey400i

    SouthJersey400i Formula 3

    Mar 14, 2007
    1,679
    Romulus, NY (Finger Lakes)
    Full Name:
    Ken Battle
    #4 SouthJersey400i, Jul 18, 2011
    Greg
    Please use 93 octane. It will not solve an ethanol 'boiling' problem since there is 10+% ethanol in both, but I am sure your engine will like it a lot better. Ferrari says 94 minimum, but that is hard to find anymore.

    Ethanol's boiling point is 173 F, so it must have been hot under your car. It is possible with the pumps sitting between two exhausts.

    I don't feel at all blessed to have corn based ethanol in my fuel.
    Ken
     
  5. Highmiler

    Highmiler Formula Junior

    Dec 8, 2010
    414
    Missouri
    Full Name:
    Greg
    #5 Highmiler, Jul 18, 2011
    Last edited: Jul 18, 2011
    Thanks for the advice.
    Here in Missouri we can still get 91 octane unleaded fuel without ethanol and I'll be going back to it.
    With 8.5 to 1 compression I had bugun to think better fuel wasn't needed. But I agree, for a few cents difference in price, it isn't worth the risk to the engine.
    Unfortunately, if you are running through Iowa, there is nothing but ethanol fuel and some of them have more ethanol than the others. They call these "Plus" and they are supposed to be 89 octane. Their price is the same as "regular 87" so go figure.
    I don't feel "blessed" about a lot of things and the ethanol boondoggle is one of them.
    Greg

    P.S. For those unfamiliar with the area, the State of Iowa is a leader the US for hog production, corn production and ethanol subsidies.
     
  6. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,841
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    #6 Steve Magnusson, Jul 18, 2011
    Ken -- you should recheck that F spec. Ferrari usually uses the RON octane fuel rating number in the specs; whereas, in the US, we use the AKI octane fuel rating on the pumps. A 94 RON rated fuel is equivalent to an 89 AKI rated fuel -- so don't waste $ needlessly -- just a thought....
     
  7. tr0768

    tr0768 Formula Junior

    Oct 28, 2008
    736
    Lake Stevens Washington
    Full Name:
    Howard Musolf
    #7 tr0768, Jul 18, 2011
    If you go to "cleanfuels.com" you can find filling stations that have ethanol free fuel. I'm lucky as I have once such station within 5 miles of my home. I do have to share the pump with pilots from the local airport hauling 5 gallon cans of enthanol free fuel back to their airplanes. Ethanol has invaded our country like the second coming. It is heavier than gasoline, it separates and drops to the bottom of the tank when a car is stored for any length of time.

    I have written several posts regarding the perils of ethanol in aluminum tanks, which is why my 308 is still on the blocks due to corroded fuel tanks. Now our idiot governor wants to increase the ehtanol content from 10% t0 20%, for faster destruction of our aluminum fuel systems.

    Howard Musolf
    308gtsi
    400i Cabriolet
    1988 Lotus Esprit Turbo
    2 many brass era cars.

    Cars owned and sold
    1959 Ferrari Testa Rosa factory race car tr0768
    2004 Maserati Spider
    1909 Stoddard Dayton
    1915 Packard twin six limosine
    2 many others to mention
     
  8. Ney

    Ney F1 Veteran
    Silver Subscribed

    Apr 20, 2004
    7,385
    #8 Ney, Jul 19, 2011
    Pure-gas.org maybe?
     

Share This Page