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?'s about av-gas.

Discussion in 'The Garage' started by jk3078, Aug 6, 2006.

  1. jk3078

    jk3078 1/2 ton status

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    The local airport sells aviation gas, 104 octane I think, and I am considering putting 5-10 gallons in my truck for the mud races next weekend. Anyone on hear ever run this fuel? How much of a differance will it make from the 87 I usualy run in this truck? I'm just looking for some tricks to give me a bit of an edge on the competion. The truck is a 3500# 85 suburban truggy running a bone stock 350/700r/208 shaved 10bolt welded/shaved 12 bolt welded/ 4.10's and 36'' Irok's on a 100'' wheelbase. Thanks
     
  2. neverendingproject

    neverendingproject 1/2 ton status

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    I think its more like diesel than gasoline. I could be wrong though.
     
  3. perp

    perp 1/2 ton status

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    You're thinking of Jet A (Kerosene)
     
  4. nvrenuf

    nvrenuf NONE shall pass! Premium Member

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    Octane ratings are achieved differently forr aviation fuel than automotive gasoline, if you want racing fuel buy the real thing. I read once that av gas with a rating around 100 was more comparable to mid 80's rated auto gas. You'd probably do just as well buying a can of octane boost.
     
  5. sled_dog

    sled_dog 1 ton status

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    Don't do it.

    An engine will make more power on the lowest octane it can run. If you can run 87(which you can) run it.

    AV fuel is not like diesel. Its higher octane, sometimes low lead containing gasoline.
     
  6. supersize75k5

    supersize75k5 OrganDonorRacing.com

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    if your motor is running fine and not pinging I would not try it, the higher the octain the longer and harder to burn, pretty much it wont do much, I am not sure but I wonder if it could even hurt the performance???
     
  7. sled_dog

    sled_dog 1 ton status

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    ]

    it could/would. harder to ignite + slower burn last I checked didn't = more power.
     
  8. ivie29

    ivie29 1/2 ton status

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    I tried running 110 in a mud race once and it didnt run right until I mixed in some 91 then it was perfect.
    My engine has some mods so it liked a little higher octane but with a stocker i dont think that you will see any difference.
    And if you have a catalatic converter dont use av gas cause the lead and the high octane will cause some issues.
    Good luck
     
  9. tomford

    tomford 1/2 ton status Premium Member

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    Well most Av-Gas is 100LL which is 100 octane Low Lead so it's not unleaded, ive herd the lead messes up the Cat's. Oh yea one more thing is the av-gas is about $4.50 a gallon

    tom ford
     
  10. jarheadk5

    jarheadk5 1/2 ton status

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    Avgas (aviation gasoline) sold in the US today is one of three varieties:

    - 80 octane, with lots of tetraethyl lead. RED in color; semi-rare today.
    - 100 octane, with lots of tetraethyl lead. GREEN in color; semi-common today.
    - 100 octane Low Lead (100LL), with less tetraethyl lead. BLUE in color; most common today.

    ALL avgas has tetraethyl lead in it. Lead is death to catalytic converters; that's one of the reasons leaded auto gas went away in the 70's.

    There used to be other grades of avgas with higher octanes, but they haven't been made in decades. And if you know someone who knows someone who knows someone who knows where there's some old 145 octane "purple" avgas... don't waste your time & energy. The aromatic hydrocarbon compounds that gave purple avgas it's high octane rating evaporated a LONG time ago.

    As the engine gurus here will tell you, high-octane gasoline alone won't give you any extra power.
     
  11. blazinzuk

    blazinzuk Buzzbox voodoo Premium Member GMOTM Winner

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    x2 even if you put 91 octane in it if it runs fine on 87 then to get the best power out of it you would have to mess with the timing. Mabey give it a tuneup but higher octane does not mean higher power if the engine wasn't designed for it. As a side note the owners manual in my 73 says to run it on 91 octane gas
     
  12. sled_dog

    sled_dog 1 ton status

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    with the advances in fuel quality since 1973, I'd bet 87 is a better choice at this point.
     
  13. blazinzuk

    blazinzuk Buzzbox voodoo Premium Member GMOTM Winner

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    Yep you are right but in Idaho our lowest octane rating (hence the cheapest fuel which is what i am going to buy) is 85 octane so thats what I run it on
     
  14. jk3078

    jk3078 1/2 ton status

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    Thanks guys. I think I will skip the av-gas, I was getting mixed answers in my area up here so I thought I would post up.
     

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