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air cooled fuel lines

Discussion in 'Performance' started by chris taylor, May 11, 2016.

  1. Alpal

    Alpal Moderator Staff Member

    Melbourne Bend of Islands
    Also this lot:

    "Here’s the thing: you can put a higher octane fuel in a car than the manufacturer’s requirement. No problem with putting 95 or even 98 in a car designed for 91 – except generally you will be wasting money. Higher octane fuels don’t contain more energy. Octane rating is basically resistance to burning under pressure, allowing higher compression ratios to be used (cylinder pressures, actually). A modern engine designed for 91 will even deliver a very small amount of additional power if fed 95 or 98 because it will advance the timing a little more than with 91. The improvement will be very minor. So minor you probably won’t notice it.
    Most engine design experts I’ve ever spoken to regard running higher octane fuel in an engine designed for a lower octane fuel as basically a waste of money."
  2. syncro

    syncro Well-Known Member

    Southern Highlands
    There are other differences besides the knock.

    Most of these "experts" are journalists.
    chris taylor likes this.
  3. chris taylor

    chris taylor Well-Known Member

    adelaide sth aust
    Alpal, this what I have read before on some American site but could not locate it again when I required it, and no doubt they would correct, the site I looked at previously was written by a VW racing team of some sort in the states, and his comments were the same as above , my concern is not about getting extra power, running cooler or smoother but protecting my engine and other components from the ravages of Ethanol "ie" rusted fuel tanks and stuffed up fuel lines and potential fire risks.
    So until I can be satisfied in my own mind that those risk have been eliminated then I will stay with 95.
    Alpal tks for your comments ,Chris ,See you at lake Macquarie.
  4. chris taylor

    chris taylor Well-Known Member

    adelaide sth aust
    Hi Col ,reading through your comments I cannot say that I would fully understand all of it , but lets see if I am getting some of it ,
    If someone is running a 95 or 98 oct to try and increase there performance and or power, it cant happen unless they increase the compression ratios , timing and general tuning of said engine .
    Also haven't both Tetraethyl and Toluene both been banned now overseas and in Australia and if so what components are now in use to eliminate Knocking.
    Are the valve saver petrol additives the same as anti knocking agents .
    Although I am aware that Diesel engines will varnish up did no know that petrol do also .
    PS didn't get on to wiki.:).
    regards Chris
  5. cbus

    cbus Well-Known Member

    sunshine coast
    There are caveats
    but in simplest form;
    If your engine runs well on 91 and the blend doesnt have ethanol the sky will not fall.

    There is no additional energy in a 95 or 98 compared to 91

    Tetraethyl lead is banned in most countries.
    Some of the substitutes for tetraethl lead may be banned.
    From memory without checking MMT is banned at present in most USA states due to environmental issues.
    It is used in Au.
    Toluene is a common component everywhere as a component of fuel blend and for its associated anti knock properties.

    Alcohol and toluene are fuels and part of the blend in many final products ( petrol)
    The other additives such as Teyramethyl lead and MMT and others generaly alter the combustion process ( prevent knock) and are in small amounts.

    Valve saver ( re, valve seat recession) and anti knock are totaly separate issues.
    It just happened that lead worked on both.

    We do not need valve saver as we now run hardened valve seats and better valve material.
    Valve guides may be an issue?

    Check wiki for thermodynamics relating to internal combustion engines
    Last edited: May 19, 2016
  6. AC-T3

    AC-T3 Well-Known Member

    Woy Woy
    Thanks all for this is a great read. Just to throw a little more fuel on the fire I can recount an experience a few years back when I was able to run my stock 1600 TP Beetle on 100-130 AvGas fortified with a full load of tetra ethyl lead. Yes there was a definite and clearly evident change. Not in elapsed times down the 1/4 mile, not in economy, not in nothing except the exhaust pipe was a nice silver grey colour. Drove just like a beetle either freeway or round town, so gotta agree with Alpal. Putting higher octane fuels into a low compression engine is just as effective as flushing dollars down the dunny. And to confirm Cbus' reference to planes being shot out of the sky with TEL replacements - it is true.
    Resnort likes this.

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