I agree Chris. I always thought they were simply there to allow separate
movement of the engine and the body. My MGTD has a flexible hose section in
the oil line to the firewall for this purpose.
I was sent this website that explains a similar installation for brake
lines.
http://auto.howstuffworks.com/question453.htm
Dallas
----- Original Message -----
From: "Chris Masucci" <sooch@houston.rr.com>
To: "Dallas Congleton" <dcong996@earthlink.net>; <healeys@autox.team.net>;
"jerry adams" <cjerryadams@yahoo.com>
Sent: Wednesday, October 12, 2005 8:31 PM
Subject: Re: Why, oh Why?
> I'm with you Dallas. From what I know of fluid dynamics, you're right.
The
> loops can provide no damping of pulses, since they are full of fluid. I
> seem to remember a while back (on another topic) other folks saying that
you
> have to bleed the line at the gauge to get accurate readings, or in other
> words, make sure there is no air in the line.
>
> The loops can only be there to allow movement, so the lines do not fatigue
> too quickly.
>
> Cheers,
> Chris
> BJ8
>
> ----- Original Message -----
> From: "Dallas Congleton" <dcong996@earthlink.net>
> To: <healeys@autox.team.net>; "jerry adams" <cjerryadams@yahoo.com>
> Sent: Wednesday, October 12, 2005 3:22 PM
> Subject: Re: Why, oh Why?
>
>
> > Please explain further for a country boy how the loops "smooth out"
> > pulsations in the oil? The system is hydraulic once it is filled with
oil
> > and no compressibility can take place, except for air trapped in the
> > system.
> > Trapped air is normally the cause for erratic needle fluctuations
because
> > of
> > its compressibility and requires bleeding to correct.
> >
> > My understanding is the vertical loops and siphons seen on steam system
> > gauges and control devices are there to isolate the bellows and
diaphragms
> > of the devices from raw steam. They condense water in the top half of
> > the
> > "pigtail" which remains as a temperature buffer. They are not for
> > pulsation
> > control. Pulsation control requires one of several different dampening
> > devices.
> >
> > Steam of course is not hydraulic like oil so I don't follow the analogy.
> >
> > Most horizontal loops on steam systems are for mechanical pipe
expansion,
> > although I don't remember complete loops
> > .
> > Also many oil gauge lines are actually steel so the copper work
hardening
> > theory wouldn't apply?
> >
> > Dallas Congleton
> > 1967 BJ8
> > 1953 MG TD
> >
> > ----- Original Message -----
> > From: "jerry adams" <cjerryadams@yahoo.com>
> > To: "Brashear, Jack, N" <JNBrashear@garverengineers.com>
> > Cc: "Healey list" <healeys@autox.team.net>
> > Sent: Wednesday, October 12, 2005 2:48 PM
> > Subject: Re: Why, oh Why?
> >
> >
> >> Jack,
> >>
> >> David Nock hit part of the nail on the head. The loops are there to
stop
> > pulsations, either fast or slow. The fast pulsations from the oil pump
> > can
> > be smoothed out also the slow pulsations from the heating and cooling of
> > the
> > oil temperature will also be "smoothed" out. Actually the heating and
> > cooling can be called expansion and contraction. This little
engineering
> > design was dreamed up back in the 1800s or earlier when steam engines
were
> > being developed more and being used in more than trains and ships.
> >>
> >> These loops should be an all Austin-Healeys.
> >>
> >> Jerry
> >> BN2
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