To add some heat to the compression test issue:
When your piston compresses the air in your cylinder, the pressure is
raised by two mechanisms. First there is the obvious effect of fitting the
same amount of air in a smaller space. Second is an increase of
temperature due to the compression. Hotter air means higher temp- just
take a balloon outside in the winter (where they actually have a winter,
that is). Another trick showing this phenomenon is to take a rubber band
and stretch it (add energy) and touch it to your lips. It will feel warm.
Release it and touch your lips again- it will feel cool. A remember many a
thermodynamics problem in between drinking binges that centered on just
this issue. There are tables in the back of these books to look up how
much temp rise for how much compression given the gas and degree of
dryness. I would guess that is where Barney's 1.41 constant came from.
The MGA survived the week of commuting unscathed. After much though, I
have decided to leave the top up for a while longer because I am stubborn
and will naturally do the opposite of what I am told. Besides, driving an
MG in the Fall with the top up reminds me of my misspent youth- getting up
early and going duck hunting, grouse hunting, crow hunting, raccoon
hunting, or just going out and shooting something out of general principal.
I remember when I first moved to the city. I wondered how this many
people could possibly remain entertained since it was illegal to discharge
firearms within city limits. Anyway, I think having the top up holds the
smells in better and I have heard that your sense of smell is strongest for
nostalgia effect. Come to thing of it, I haven't shot anything for a
while...
Regards,
Bill Eastman
61 MGA with an "Easy Rider Rifle Rack"* mounted instead of a luggage.
*Cheech and Chong, Big Bambu
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