Hmm looks like to me that the tubes are connected to the vacumn fittings on
each carb body that are there to recycle fumes from the side cover
vent/crankcase back into the motor via the carbs - but it's very difficult
to see on the pics exactly where it's connecting to. The system was called
CCV? or something or other - my guess without my Bentley manual -
"Carburettor Crankcase Ventilation system".
Fuel overflow is handled by a horizontal exit pipe on the float chamber lids
front and rear. Fuel enters via a single input on the front carb float
chamber lid only (3 inputs on front lid, 2 on rear), an inline filter is
used. The front carb then serves the rear carb connected by a braided fuel
hose.
For the actual overflow, there should be a short piece of rubber tube from
each of the float chamber vents (about 1-2") and this is in turn connected
to a piece of steel pipe, which has a brass T exit towards the rear carb.
This T exit is joined by another rubber tube which in connects to an input
on the Charcoal cannister. Overflowed gas then passes down a tube secured to
the firewall and exits down by the gearbox well away from the exhaust (in a
LHD car).
I have no idea what that contraption pictured is for. I imagine all it does
is prevent air from entering the motor via the carbs as I see no entrance
point for the filter - which I *guess* could be being used as a quazi air
filter IF it had an input! Total waste of time and says to me whoever did
that had no idea! <G>
I hate to think what it would do in practice, I guess nothing, but it can't
be good the way it is now! Ditch it! :) You should find an example of the
correct carb set up in the excellent Moss catalog available in PDF format on
the web.
In a working CCV, The single front side cover tube is split with a Y plastic
connector into two tubes which connect to the front and rear carb vents as I
mentioned above. The vacumn from the motor draws fumes from the crankcase
back into the engine instead of exiting them to atmosphere.
HTH,
Neil
--
61 A / 70 BGT / 68 CGT/ 56 BN2
URL: http://www.apphosting.com/mgstuff/
----- Original Message -----
From: Steve Shoyer <Steve@shoyer.com>
To: <mgs@autox.team.net>
Sent: Monday, July 10, 2000 6:02 PM
Subject: RE: '75 MGB Carbs, Steering Boots, emails, etc.
> It looks like someone has connected the two overflow lines from the carbs
> together with the filter in the middle. It doesn't look like there's
> anywhere for the excess fuel to go (no line to a carbon cannister) besides
> the other carb, so maybe the see-through filter is a way to see if any
fuel
> is overflowing. It doesn't make sense to me if that's really what it is,
> but people do funny things.
>
> --Steve (1980 MGB)
>
> -----Original Message-----
> From: Mark Dawson [mailto:mark.dawson@bones.org]
> Sent: 10 July 2000 04:25
> Subject: '75 MGB Carbs, Steering Boots, emails, etc.
>
> ... But this thing, and what it is
> supposed to do, is beyond me. Any clue?
>
> http://www.bones.org/torch/photos/mgb/carbs_whats_this.html
>
> What's this tube, why is there a fuel filter in the
> line, and why does said filter appear to be completely
> dry and never used?
>
> Here is a picture in situ, for reference:
>
> http://www.bones.org/torch/photos/mgb/engine_compartment.html
>
> Should this be full of fuel? Is only one carb working,
> or what gives? I can't seem to find a similar picture
> in any catalogues or manuals....
>
|