That brings up a good point, actually. There are two methods for
calculating the Octane rating of gasoline, as shown in the following
article I found on an MG website:
"In Britain, the Research Octane Number (RON) is used to indicate a
fuel's octane. This number is derived from tests on an engine running
at a constant speed of 1500 r.p.m., conditions that do not closely
relate to those found in real situations. In order to address this
disconnect with reality, the Motor Octane Number (MON) system was
developed using a tougher test carried out at higher engine speed and
temperature. In the US and Canada the two systems coexisted for a
while -- causing much confusion. To resolve the matter the U.S. Cost
of Living Council (CLC) index, better known as. Anti-Knock Index
(AKI), was introduced and is simply the arithmetical average of RON
and MON; so AKI = (RON + MON)/2 and is the number now familiar to
motorists in the USA and Canada. Yet another measure may sometimes be
referenced: Road Octane Number (RdON).This is considered the best
predictor of octane but it is determined by running a vehicle on the
road or using a chassis dynamometer, and it is too dependent on the
actual engine under test. RdON is so close to AKI that they are often
used interchangeably. There is no direct correlation between RON and
MON, different formulations for fuels with the same RON number might
well produce different MON's. You can make a rough determination,
however: for the high octane fuels we are concerned with, the
difference between RON and MON, or the "sensitivity" as it is known,
is about 10. If you know the AKI therefore you can add or subtract 5
to determine the approximate RON or MON respectively. "
Cheers-
Steve Hall
----- Original Message -----
From: "mark holbrook" <rolling_rock_12@yahoo.com>
To: "Graham Stretch" <technical@iwnet.screaming.net>
Cc: <spitfires@autox.team.net>
Sent: Monday, June 12, 2000 8:52 PM
Subject: Re: Fuel
>
> Yes I know that back in the day Triumphs were designed
> to run on 100 octane. When they shipped them over
> here did the US have 100 on tap? I have had no
> problems with pinging using 94 as a daily driver
> driven hard. Also I'm not sure if you are aware of
> this but the Brit's had a different octane scale than
> the Yank's. Whether it is a higher standard or lower
> than the US Im not sure, but the car seems to scream
> the answer.
> Mark Holbrook
> GT6 convertable
> --- Graham Stretch <technical@iwnet.screaming.net>
> wrote:
> > Hi Mark
> > 94?94! the 2000, 2500 2.5PI are all supposed to be
> > fed with 100 or *****(5
> > Star UK not a swearword!)
> >
> > Graham.
> > 2500PI MKII
> > Sprinted Dolomite
> > 2000 MKI
> > Toledo
> > 1300 Front Wheel Drive
> > http://members.tripod.co.uk/TriumphIW/index.html
> >
> > ----- Original Message -----
> > From: mark holbrook <rolling_rock_12@yahoo.com>
> > To: john donohoe <gt6driver@yahoo.com>
> > Cc: <spitfires@autox.team.net>
> > Sent: Monday, June 12, 2000 10:31 PM
> > Subject: Re: Fuel
> >
> >
> > >
> > > I think this is too high. Anything over about 94
> > or
> > > so is not needed. Sure it will help clean out the
> > > engine if you use it a couple times, but I don't
> > see
> > > any advantages on a stock engine. Now when you
> > decide
> > > to to some head work and other fun stuff, this
> > would
> > > be a good idea to stop the chance of pinging. Im
> > not
> > > sure what the comp. ratio is on the spits, but my
> > GT6
> > > is about 9.75 and 94 octance is what I use. When
> > you
> > > get into the 12 to 1 ratios go get this great gas,
> > > until then, save your money.
> > > Mark Holbrook
> > > 1969 GT6 Convertable
> > > --- john donohoe <gt6driver@yahoo.com> wrote:
> > > >
> > > > I've wondered the same about the 108 octane race
> > > > fuel
> > > > available at my local svc station... If it
> > didn't
> > > > kill
> > > > my engine, I'm afraid it would be addictive!
> > (it's
> > > > like 4.50 a gallon)
> > > >
> > > > John Donohoe
> > > > '70 GT6+ KC 81718
> > > > (wouldn't know what to do with anything over 92
> > > > octane!)
> > > >
> > > > --- Craig Smith <CraigS@iewc.com> wrote:
> > > > >
> > > > > I was tooling around this weekend in my 71 and
> > I
> > > > was
> > > > > at a parking lot of a
> > > > > local adult beverage seller when a fellow came
> > up
> > > > in
> > > > > a custom crotch rocket.
> > > > > I think it used to be a Kawasaki, anyway, the
> > > > > exhaust smelled a little funny
> > > > > so after he shut it off and the ground quite
> > > > > shacking I asked him if was
> > > > > burning Methanol. He said it was aviation fuel
> > !
> > > > 140
> > > > > Octane, he buys it at
> > > > > the local private airport, this caused me to
> > > > > think,,, what would a couple
> > > > > gallons of that do in our 8 gallon tanks to
> > the
> > > > > heads and valves or our
> > > > > spits ?
> > > > >
> > > > > I would think it would burn very well if it
> > didn't
> > > > > burn the tips off the
> > > > > plugs or worse burn the valves clean out of
> > the
> > > > > head.
> > > > >
> > > > >
> > > > > Craig Smith
> > > > > 36 Pelham Ridge Drive
> > > > > Greenville, SC 29615
> > > > > 800/692-2323 ext. 2105
> > > > > 864/234-1020 fax
> > > > > e-mail: craigs@iewc.com
> > > > >
> > > >
> > > >
> > > >
> > __________________________________________________
> > > > Yahoo! Photos -- now, 100 FREE prints!
> > > > http://photos.yahoo.com
> > >
> > >
> > > =====
> > > -Mark Holbrook-
> > >
> > > __________________________________________________
> > > Yahoo! Photos -- now, 100 FREE prints!
> > > http://photos.yahoo.com
> >
>
>
> =====
> -Mark Holbrook-
>
> __________________________________________________
> Yahoo! Photos -- now, 100 FREE prints!
> http://photos.yahoo.com
>
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