At 07:03 PM 4/01/02 +0930, you wrote:
>The lead in petrol is only a cheap way of improving the octane rating of the
>fuel. The octane can be improved by more environmentally friendly means
>through distillation & blending but this is of course more expensive. The
>Australian automotive industry used to ake advantage of the cushioning
>properties of the lead to manufacture valves and seats that were of very
>soft steel. Fortunately technology has overtaken these practices and we
>enjoy very good engines in our cars these days which will withstand even LPG
>and LNG fuels which have no cushioning effect at all. The cushioning of the
>valves in larger industrial reciprocating engines is achieved by using high
>ash lubricating oils which achieves the same thing as the lead in petrol. I
>believe the new lead replacement also has a high ash property for this
>purpose.
>
>However I don't know how this applies to aviation fuels and octanes of 100.
>From memory Super is an octane of 92 and unleaded is an octane of 87.
>Premium unleaded will come somewhere in between.
>
>regards
>John Ashford
>Alice Springs
According to "Sport Aviation", the EAA magazine there is no satisfactory
way of making unleaded avgas suitable for 100LL or 100/130 engines. There
has been quite a bit of research to this end. The other additives are
either horribly expensive or just horrible as far as toxicity goes.
There is now also a 91/98 avgas standard that is lead free. This is used in
Sweden and has been revived for the US but as yet you can't buy it, just
like you can't buy 82UL yet.
Mike Borgelt
Borgelt Instruments - manufacturers of quality soaring instruments
ABN 75532924542
Box 7474 Toowoomba M.C.
Queensland 4352
Australia
Tel 0746 355 784
mob 0428 355 784
0429 355 784
fax 0746 358 796
International
phone: int'l+ 61 7 46 355 784
Cellphone:int'l +61 4 28 355 784
int'l +61 4 29 355 784
fax : int'l+ 61 7 46 358 796
email: [EMAIL PROTECTED]
website:www.ozemail.com.au/~mborgelt
--
* You are subscribed to the aus-soaring mailing list.
* To Unsubscribe: send email to [EMAIL PROTECTED]
* with "unsubscribe aus-soaring" in the body of the message
* or with "help" in the body of the message for more information.
