I certainly do not consider myself an expert on gasoline formulation,
however, I have gained a little experience with high performance street
cars and true vintage race cars in the US. The difference between the
two is extreme.
I owned and regularly drove an AC Cobra replica with a 425 HP Ford 351W
engine. It ran great on 93 octane unleaded gasoline. About the only
change I noticed on the two occasions I added octane booster was the
awful odor--bad enough to make me stop using it. No problems in five
years, and the new owner runs it even harder with no complaints.
I always use 110 octane leaded racing fuel in my Formula Ford and
Formula B. I saw a Spec Sprite race car try to save some money last
year by using 93 octane unleaded on the track. The result was piston
heads that were literally melted.
Surely there will be unleaded fuel at the race tracks in the UK. On the
road, good quality unleaded should not be a big problem.
Only one man's opinion!
Richard
Brian Evans wrote:
>
> My personal experience, on street cars (Mini's and MGB) is that I've had no
> failures as a result of unleaded gas. No extreme valve seat wear. We've
> had unleaded gas for a hell of a long time (a decade or more), and the MGB
> is still waiting for it's first valve job. The answer, I've been told, is
> that the cast iron valve seats work harden to a sufficient degree to resist
> the erosion due to lack of lead to lubricate. It's very easy to put
> hardened exhaust seats in if you're worried - but that's also the cure if
> you have a problem so I've decided to wait until the problem arises rather
> than prejudging the decision.
>
> On race cars, the unleaded gas offers a different problem. The issue isn't
> valve seat wear - you tend to re-do valve seats pretty often for other
> reasons. But unleaded race gas, when used in high compression engines,
> seems to be trickier to setup for, and several engines have been lost on
> the dyno, etc. due to pre-ignition. Plus the stuff they put in unleaded
> race gas is amazingly awful - if I'm following a car running the stuff on
> the track my eyes literally water from the fumes! Solids can precitipate
> out of solution if exposed to sunlight, etc. One brand apparently (rumour
> here) doesn't even legally qualify as gasoline - not enough gas in it!
>
> After the first six months or so, a decade ago, I stopped using lead
> substitute and have never re-started as I never had a problem.
>
> Cheers, Brian
>
> At 06:38 AM 11/10/1999 -0500, you wrote:
>
> >Now the European Gov has seen the light and decided to poison us all with
> >Benzine instead of lead, in the UK we no longer have a sourse of Leaded
> >Petrol.
> >
> >Whilst Lead Replacement petrol will (probably) cope with the stresses of
> >ordinary motoring in the UK, does anyone out there have any experience of
> >"hard motoring" using unleaded on engines designed for lead. By hard
> >motoring I mean racing/fast road cruising at engine speeds of 4500rpm
> >plus.
> >
> >The questions that I (and many others) would like answers to include
> >1. Which adddatives are people using abroad.
> >2. At what doesage rates
> >3. Does anyone have any experience of teh Redline addative?
> >
> >If you have any input and would like to send replies to me, I will collate
> >them and reply to the list
> >
> >thanks
> >
> >Geraint Owen
>
> Brian Evans
> Director, Global Sales
> UUNET, An MCI WorldCom Company
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