----- Original Message -----
From: "Jeanne Lacourse" <cckw@mediaone.net>
To: "Military Vehicles Mailing List" <mil-veh@mil-veh.org>; "Richard Notton"
<Richard@fv623.demon.co.uk>
Sent: Sunday, November 12, 2000 12:04 PM
Subject: Re: [MV] Diesel
> I have not heard of this problem with the newer gasoline. Are all WW2
> engines subject to this?
>
It does seem to vary even from engine to engine.
> What are the symptoms of excess octane, overheating, valve problems, etc?
>
You certainly do not realise the potential power in higher octane fuels
using older engines not designed for them, localised overheating and exhaust
valve troubles can occur but poor maintenance and especially timing errors
make a large contribution.
We are of course unfamiliar with your gas formulation although the winter
MTBE stuff I read about here seems some obnoxious stuff that many WWII MVs
don't like at all.
It is circumstantial but commonly the MV people together with the classic
car types all seem to regularly have both vapour lock and icing troubles
now, we do know officially the UK air regulator (CAA) will not permit motor
fuel approved aircraft to operate on this with the tanks at or above 20 deg
C at take off because of potential vapour locks or operate above 5,000ft
owing to likely carb icing.
The Solex 48NNIP to be found on Stalwart, FV432, Fox and Scorpion seems
particularly prone to idle icing on pump fuel as I have seen in our
generally damp climate as it gets cooler, although the phenomenon can occur
on humid hot days too. This certainly is not a trait on army MT80 gasoline
which does seem more like AVGAS than the very rapidly self-vaporising
domestic pump fuel we get here.
Richard
Southampton - England
This archive was generated by hypermail 2b29 : Sun Dec 03 2000 - 20:29:51 PST