Charley,
I think that the volatility as measured by RVP varies from season to
season & state to state depending upon state environmental laws &
summer/winter temperature differences. A "typical standard" might be 7
psi summer - 13 psi winter. The CARB in California is especially picky
about evaporative emissions & tries to keep RVP as low as possible.
If you get stuck with winter gas on a hot day there may be some troubles
with vapor lock or carburetor boiling. This can easily happen with a
seasonally driven car where you fill up in late fall, store the car, &
take it out again on a hot spring day. You are stuck with having to run
out the whole tank before refilling with summer grade gas.
I agree with Bob about no correlation between RVP & octane. Also that
aircraft have special requirements for RVP.
Dave Russell
BN2
Bob Spidell wrote:
> I don't believe there is much, if any, correlation between octane
> rating and vapor pressure, although there is some variation between
> different blends (summer/winter formulations, gasahol, etc.). Any difference
> is liable to be slight regardless.
>
> At any rate, there are methods to test the Reid Vapor Pressure--the
> standard method of measurement--that are used by pilots who use
> auto gas in aircraft.
>
>
> bs
> ********************************************
> Bob Spidell San Jose, CA bspidell@pacbell.net
> '67 Austin-Healey 3000 '56 Austin-Healey 100M
> ********************************************
>
> ----- Original Message -----
> From: "Charley Braum" <cbaustin@verizon.net>
> To: "Neil McDonald" <nimcdonald@shaw.ca>
> Cc: "Healey List" <healeys@autox.team.net>
> Sent: Thursday, July 08, 2004 7:48 PM
> Subject: Re: Hot Problem
>
>
>
>> Further to the 'Hot Problem' thread - is there a relationship between
>>fuel octane and vapor lock (boiling). In other words, if I use a higher
>>octane fuel, will I experience vapor related mis-firing at lower
>>temperatures?
>>
>> Thanks,
>>
>>CB
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