Aviation Gas in a Ferrari? | FerrariChat

Aviation Gas in a Ferrari?

Discussion in 'Technical Q&A' started by POLO35, Feb 14, 2008.

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  1. POLO35

    POLO35 Formula Junior

    Feb 21, 2005
    781
    Treasure Coast Florida
    Full Name:
    MATT
    I have been running my Mercedes diesel on "waste jet fuel" for two years now.....for free!....WEll, I now have a unique opportunity to acquire the "waste AV gas" from our local private airport.....for free. Each morning, the line guys "sump" the fuel trucks for water/sediment. The fuel is quite clean, but I let it settle and filter to 2 micron just on principle. Anyway, do you think AV gas would be suitable to run in a Ferrari....or any gas car for that matter? Thanks in advance.
     
  2. GTHill

    GTHill F1 World Champ
    Lifetime Rossa Owner

    Jul 1, 2006
    14,054
    Double Wide
    Full Name:
    GT Hill
    Av gas may make it harder to start since it has a higher ignition temp but most likely it won't have that effect. From an operation perspective I don't think it will hurt it, but my concern would be if there are any corrosive properties to av gas. Plenty of experts here to help.

    Gene
     
  3. mousecatcher

    mousecatcher Formula 3

    Dec 18, 2007
    2,116
    san mateo, ca
    besides being illegal, the lead will foul the O2 sensors.
     
  4. RMDC

    RMDC Formula 3

    May 15, 2005
    1,005
    Boston, North Shore
    It's 100 octane and low lead (100LL) - Go for it! Better fuel costs more, but you do not pay highway use taxes.
     
  5. GTHill

    GTHill F1 World Champ
    Lifetime Rossa Owner

    Jul 1, 2006
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    GT Hill
    Didn't know that it was illegal but I remember the O2 sensor thing. I once put av gas in my brothers dirt bike. Ran fine but no O2 sensors in that :)

    Gene
     
  6. AntonyR

    AntonyR F1 Veteran

    Apr 12, 2004
    5,426
    Los Angeles
    Full Name:
    Antony
  7. POLO35

    POLO35 Formula Junior

    Feb 21, 2005
    781
    Treasure Coast Florida
    Full Name:
    MATT
    I am geting the specs tomorrow. I agree that it's techniaclly illegal...ie no fed taxes, but I was led to believe that Av Gas is really a "premium" version of premium and no lead. The way I see it, the 328 is bullet proof, if anything, it should run "cleaner". The down side is that no one on this forum would want to buy the car years later if it had been run on it......Upside, of course, is free fuel!
     
  8. wingfeather

    wingfeather F1 Rookie

    Feb 1, 2007
    3,653
    rock bottom
    Jets run off diesel?
     
  9. solofast

    solofast Formula 3

    Oct 8, 2007
    1,773
    Indianapolis
    Av gas in any car with catalyst systems is a no-no.

    Not only will it destroy your O2 sensors but it will clog up your cats and ruin them.

    100 octane "Low Lead" isn't actually low lead at all. It has about four times the lead content of the old 87 octane leaded gasoline that was common before unleaded fuel became the norm. It is only lower in lead content than the previous version of 100 octane avgas.

    Avgas and fully synthetic oils do not mix! It was found that the fully synthetic oils are unable to capture the lead and carry it out of the engine at subsequent oil changes. The result is the lead accumulates on the spark plugs, piston rings, valve guides and generally throughout the engine. In some cases the fully synthetic oils would cause the lead to form a thick paste that would plug oil galleries and even the oil cooler! If you must use Avgas then use mineral or semisynthetic oil and change the oil more frequently

    The liquid cooled cylinder head in cars is also a problem with a lead enhanced fuel. In simple terms it runs too cold. The head never gets hot enough to allow the lead to “purge” itself of the deposits and they build up over time. In comparison, an air cooled head has massive heating and cooling cycles that keep lead contamination more under control. As anybody who is a pilot and has picked balls of lead out of his bottom spark plugs will tell you there is a lot of lead in avgas.

    Avgas has very low vapor presure. On cold days it can result in starting problems.

    Lastly, the flame propagation speed is lower for avgas and, if you do not advance the timing, can result in burned valves because the exhaust temperatures can be higher.

    Old car engines with high comprssion and racing engines that are pushing the edge of detonation can use 100LL, but it is a really bad thing to put into a modern car, and in particualr any car that uses catalyst systems and O2 sensors.
     
  10. GTHill

    GTHill F1 World Champ
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    Jul 1, 2006
    14,054
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    GT Hill
    I'm not sure if you meant of or not, but it is a myth that higher octane means "cleaner". Technically higher octane fuel actually has less energy. You can produce more HP with av gas because you can run at higher compression. Just my .02.

    Gene
     
  11. solofast

    solofast Formula 3

    Oct 8, 2007
    1,773
    Indianapolis
    JetA fuel is a "close cousin" to diesel. One of the key differences is that it is blended with much less wax in it. Diesel fuel as most folks know turns to "jelly" at very low temperatures. Jet fuel gets really cold at 30,000 ft, since it is in wing tanks that are having cold air rush over them at high speed when you are flying at high altitude. In short, diesel fuel won't flow when it gets that cold. One of the issues with the lower wax content is that jet fuels have lower lubricity than diesel fuels. That is, the injector pump doesn't get as much lubrication as it would with diesel fuel. Now, maybe if it's free you can save enough to buy a new injector pump, or if you are doing "everyday" driving and aren't running it hard enough to notice the wear, but if I were going to run JetA in a diesel car I would try to mix it with diesel fuel in a 50/50 mix to help protect the injection pump....

    I guess the bottom line is that "free" fuel may end up costing you a lot if you screw up your engine. The best thing to do is to run your vehicles on the fuel that they are designed for, if you want a long trouble free service life.
     
  12. FandLcars

    FandLcars F1 Rookie

    Aug 6, 2006
    3,057
    Tempe, Az
    Full Name:
    Rick Schumm
    Haven't flown for quite a while and haven't looked up specs on 100LL, but I think Low Lead is a relative term. IE, I think LL has enough lead in it to harm cats, compared with auto Unleaded. Definitely is illegal due to Fuel tax issue mentioned.

    I understand diesel in Europe is cheaper than gas, and so many private aircraft are being converted to diesel over there, in spite of hefty conversion cost. Diesel aircraft conversions are available here, but no money to be saved on fuel cost here.... I paid more for diesel here ($3.50 I think) a couple weeks ago to refill a rental truck here.

    Rick
     
  13. No Doubt

    No Doubt Seven Time F1 World Champ

    May 21, 2005
    72,740
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    Mr. Sideways
    Sump-dumped avgas has a higher content of lead...that's why it's at the tank bottom with the water and sediment that needs to be drained. Ordinary LL avgas already has about 4 times that amount of lead that old automobile leaded fuel used to have, and sump-dumped aviation fuel will have substantially more.

    I'd say that you'd notice damage on spark plugs, catalytic converters, and O2 sensors fairly quickly if you run on sump-dump. One wonders about it clogging up more substantial components in your engine, too.

    If you'll notice, even the lawn companies who mow the fields at airports avoid using "free" sump-dump in their mowers.

    I'm not sure that I'd even put it into a rental car if I was mad at the company for screwing me over.
     
  14. sc67vette

    sc67vette Karting

    Feb 28, 2007
    92
    Dallas, Tx
    Full Name:
    Steve
    100LL will harm emissions systems. Jet A is "drier" than Diesel, and therefor needs to have an additive run with it. Also, Jet A is lower in BTU's than Diesel, so your mileage will be lower. However, if free, those two issues can be addressed and you still will be ahead of the game.
     
  15. zjhoward

    zjhoward Karting

    Dec 15, 2007
    75
    Full Name:
    Zachary Howard
    Are you kidding me? Awful idea. Pay for gas for your Ferrari.
     
  16. POLO35

    POLO35 Formula Junior

    Feb 21, 2005
    781
    Treasure Coast Florida
    Full Name:
    MATT
    I appreciate all the responses. With regard to the jet fuel in the MBZ, when I say free...I mean free. The only thing I have invested is my time to pick it up, let it settle and run it through a $12.00 Racor filter. I drive alot, so I am saving around $5000.00 a year...that buys plenty of car parts. {So far, only a few glow plugs} Also, I failed to mention that I am blending it with 5-10% waste vegetable oil for lubricity. As far as the Ferrari on Av Gas....I'm still skeptical. I think I am going to test it out on my daughters MBZ 190E. I figure the car is worth 2K.....free fuel to and from school etc probably $2500/year.....worth the risk. As far as the lead in the AV Gas, I just cant believe that the FAA Would allow fuels with such awful properties.....ie the alleged "lead ball buil-up" to be used for aviation. Will keep posted.
     
  17. ArtS

    ArtS F1 World Champ
    Owner Silver Subscribed

    Nov 11, 2003
    12,645
    Central NJ
    DO NOT RUN 100LL or any leaded fuel in any car with cats. It will kill the emissions system, including the cats.

    If you remove your emissions equipment (sensors, cats, etc) then run 50% 100LL and 50% street gas. In my opinion, it is not worth the mods. If you want to run a Ferrari on avgas, get an older car ('77 or older) then you can do the 50%-50% mix without too many problems.

    I'm not sure when M-B put cats on but check this before you try.

    Regards,

    Art S.

    PS. I often run a 50% - 50% mix in my 330.
     
  18. Verell

    Verell F1 Veteran
    Consultant Owner

    May 5, 2001
    7,022
    Groton, MA
    Full Name:
    Verell Boaen
    Ditto

    Hmm, The Euro versions of the 308s thru the QV were designed to run either leaded or unleaded, & the heads on all 308s are identical so I suspect they wouldn't be subject to this problem. Offhand I'm not sure if the Euro 328s also could run leaded.

    The stock 3x8s, even the Euros don't have enough compression to benefit from high octane gas. Altho if you've added high compression pistons & aren't running cats, or are running a boosted engine, then it might be worthwhile. I know that unleaded gets a heck of an octane boost from just a a small amount of lead, so running a mix would still have the high octane & a more reasonable lead %.
     
  19. solofast

    solofast Formula 3

    Oct 8, 2007
    1,773
    Indianapolis
    Yes I am sure a 308 can run fine on leaded AUTOGAS. Almost any engine can run on some amount of lead in the fuel without a problem, (assuming that it doesn't have cats or 02 sensors) it is the amount of lead that you are burning relative to the operating temperature that causes the problems. Lead parcipitates out of the combustion process and plates itself onto cooler surfaces. If you get it hot enough it oxidizes off and goes out the exhaust pipe. The problems come from relatively cool, light load operation in cars. Aircaft typically run at 75% power, so a high lead content isn't as much of an issue, the engine is almost always at high power and is at a high enough temperature where the lead doesn't accumulate.

    It is the amount of lead in avgas messes up lower compression, lower temperature engines. Avgas has 2.0 grams of lead per gallon. Leaded 87 octane auto gas has .5 g of lead per gallon. That is four times as much lead and that's why things go to he!! in a hurry.

    Remember that in the days of leaded fuel you replaced spark plugs every other oil change or at about 6,000 miles. Remember too, that with older cars it was very common to go out and give them a 7,000 rpm tune up, going out on the back roads and running the heck out of the car. What you were doing if you went out and ran the car hard for a few minutes was burning the lead off of the plugs and by getting the head and plug temperatures high enough to clean them up. With conventional aviation engines you sit on the end of the runway doing your engine runup, it is not uncommon to sit there for a bit at high power to get enough heat into the spark plugs to clean off the lead acquired in taxing out to the runway.

    True, running higher octane than necessary gets you nothing. Also note that avgas is less dense than typical auto fuels. Avgas has a density of 5.8 to 5.9 lbs/gallon, where auto gas is between 6.1 and 6.3 lbs/gallon. That means that if you are running an engine hard you will need to rejet it to properly run on avgas. There are lots of horror stories where people put avgas into their high performance engine and then melted it down on the track because it was running too lean at high power, they didn't compensate the jetting to address the lower density. Probably not much of an issue on the street, but on the track it can make a difference that can be costly. If you mix it somewhere at around 3 gallons of unleaded to 1 gallon of avgas that might give you a decent octane boost for an older engine and it would likely not be enough to totally mess up the jetting and might get you out of any knocking problems and would bring you down to about .5 grams of lead per gallon, which is probably a safe area to run.

    Some folks have mentioned also that it is illegal to use avgas in cars, but in doing some research I found that it isn't the road tax issue, it is the EPA that really has the teeth in their penalties for using avgas in cars. AvGas can be illegal to use in anything except aircraft engines because of aromatics in general, benzene in particular, and olefins (alkene) content. Violations can carry a potential penalty of $25,000 per day of violation!
     
  20. mseals

    mseals Two Time F1 World Champ
    Lifetime Rossa Owner

    Sep 9, 2007
    24,468
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    Mike Seals
    So do the turbine engines in the Abrams M1 Main Battle Tank...actually, they have all been converted from DF2 diesel to JP4.

    Mike in Kuwait
     
  21. POLO35

    POLO35 Formula Junior

    Feb 21, 2005
    781
    Treasure Coast Florida
    Full Name:
    MATT
    Ok. I talked to the line guys at the airport and they reported the same lead issues as many of you have discussed. My Intention for using it is not for performance but merely because it's free. I am still going to use it my daughter's 190E, but no way in the 328. I wonder if there is a way to "filter" out the lead? Sounds like more trouble than its worth. By the way, the 190E has the cat removed. Thanks to all who posted and saved my 328!
     
  22. franzi@senet.com.au

    May 14, 2007
    35
    Adelaide, Australia
    Full Name:
    Lynton Franzi
    100LL has an actual octane rating of 102 and as has been correctly pointed out, has significantly more lead than leaded motor fuel and burn characteristics that are designed for aircraft power settings and relatively high cylinder head temperatures. However, as Ferrari state in a 2001 Service sheet, the 328 will run perfectly on unleaded fuel, as long as the octane rating is 95 or greater (preferably 98 or 98 depending on the brand available) even if the car was originally designed for leaded fuel usage.

    Ferrari state in this 2001 Technical service sheet that from the early 70's, the valve seats fitted to all their models are compatable with unleaded fuel and the same applies from 1977 for the American market with cars fitted with catalytic converters.

    I am using a small proportion of Avgas with high octane motor fuel in an old Jaguar that does not have hardened valve seats to provide both the lead I need and a high octane. However, in my 85 QV, (australian non cat), 98 or 99 unleaded is perfectly suitable and indeed preferable

    I am not sure what you are trying to achieve but clearly if your 328 has cats the you shouldn't use Avgas and if it doesn't, then high octane motor fuel is the go.



     
  23. solofast

    solofast Formula 3

    Oct 8, 2007
    1,773
    Indianapolis
    If you are on the ground turbines will run for a while on pretty much anything....

    Diesel is fine for most turbine engines, so long as you aren't going up to high altitude or running at temperatures where the fuel will jell. Turbine engines fuel requirement is for some lubricity, but one of the most important attributes for some turbines is that the fuel gets hot and can turn into hard carbon deposits in the fuel nozzles. In the industry we generally refer to this as a fuel coking problem, the fuel is turning into something like hard carbon coke inside of the fuel nozzles and they clog up. Jet fuel has a higher resistance to coking than diesel and that could improve the time between maintenace actions, but it is likely that you can use diesel for a good while without much ill effect. Most turbines will run fine on gasoline too, for a while. The Allison Model 250 engine has a specification limit on the amount of time that you can run automotive fuel (I seem to remember that it was like 5 hours before you had to pull the fuel pump, but I could be wrong, it's in the Bell helicopter manuals somewhere if I remember correctly) if you are stuck with only that available, the idea being that you can get home on whatever you can put into the tank. If you run a mix of jet fuel or diesel it will run for a good long time on most anything that you can put in the tank. Lots of folks run helicopter turbines on the ground and use diesel in them with no ill effects.
     
  24. solofast

    solofast Formula 3

    Oct 8, 2007
    1,773
    Indianapolis
    No you can't filter out the lead, it is in liquid form (TEL) and contary to what somebody else posted earlier, there isn't any more lead in the fuel in the tank sump, it is all blended into the fuel.

    Having the cat removed from the 190 only solves half the problem, if the car has a closed loop control system that relies on an O2 sensor it is going to be ruined in short order. The default for a failed sensor may be that the car goes to open loop control but it really isn't a good idea to run all the time in that mode.
     
  25. JCR

    JCR F1 World Champ
    Silver Subscribed

    Mar 14, 2005
    10,795
    H-Town, Tejas
    100LL is ~99 MON or ~109 RON.
    Not as compared to the 1960s through the very early 1970s. Back then, an L-88 Corvette and other high compression engines required 103 RON fuel like Chevron "White Pump" or Sunoco 260. Those fuels had about 3.5 grams lead per gallon. Some of the current leaded racing fuels are in the 4+ grams per gallon range. VP Air Race fuel which has aviation performance numbers of 120/160 has 6+ grams per gallon.
     

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