>> Marvel Mystery Oil (MMO) has been suggested several times
>> on this list for use in Stromberg dashpots. I've always wondered
>> why we should use MMO instead of the relatively heavier engine oil.
>Can't tell ya, it a mystery.
Coming from a motorcycle background, and having read the racing manual
for my Spitfire, I'll take a stab at it.
Has to do with throttle and engine response I'd suspect. For
competition, you run the dashpots dry. Same motorcycles. That way when
you slap the throttle open, the dashpot opens up as well, and you've got
air flowing into the engine. With the heavy oils, you get a long long
delay as it opens.
The song and dance about how that causes momentary enrichment is
probably accurate. Reduces throttle bog as well. Which can be a
significant problem if one doesn't bother to pay attention to the
engine. Hence, on a motorcycle (or competition set su or stromburg) you
don't just simply pop the throttle wide open from idle and expect the
engine to respond. You progressively open it yourself, instead of
letting an oil strangled dashpot do it for you.
Personally, having added oil to by Stromburg and noting what it did to
my thottle response, I'm going to turn the carb over and dump it out
before it goes back on the engine again.
|