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Closer look at new MG engine bits

To: _MGs <mgs@autox.team.net>
Subject: Closer look at new MG engine bits
From: Scott Beavis <sbeavis@solartron.com>
Date: Wed, 23 Aug 2000 11:15:32 +0100
Did some fiddling in the new MG's engine bay last night. The float bowl
overflow hoses from the carbs were split so I renewed them. They are HIF4s I
think not HIF38s as I first thought. At very first I just looked at the
dashpot and thought they were HS4s but then I noticed the float bowl
underneath and assumed HIF38s but they are not quite the same as the HIF38s
used on metros.

I checked under the dizzy cap and the ignition is running on points. I need
to confirm the dizzy number, and then hopefully get Luminition Magnetronix
system. One potential problem here is the coil is a 6V ballasted type. I
can't see a ballast resistor anywhere. Anyone know where it may be located?
I'd like to convert the ignition over to a 12V Lucas Sports Coil. This is
what I run on the mini and it always fires first turn of the key (or "press
of the button" as it is on the mini). The MG has been a bit of a pain to
start lately. Lots of pulling on chokes and varying on throttles. I richened
each carb half a turn and it started much easier, but still not as well as
it should. The engine is still coughing a bit when accelerating in 3rd gear.
It seems better with full choke so I still think the carbueration is all
cock-eyed. I'll 'colortune' it and see what turns up.

As for this 'expansion bottle' I stuck a finger inside and discovered it has
a pipe leading to the bottom, so not as bad a design as I though. The
trouble with this system is it is more of a 'replenishing reservior' than an
expansion tank. It will let steam out and then suck water back in when the
engine cools. This is ok, so long as you switch off every now and again.
Long journeys could see the coolant level in the engine dropping. A 'proper'
system has two pipes to the engine so that water can top up the engine level
at any time. The steam then leaves the system via a balance pipe to the top
of the expansion bottle, and if pressure gets up the cap vents. This is how
it is done on most 'modern' cars including metros 1980'ish on. This would
have the advantage that the engine was always 'underwater'. It does however
require the expansion bottle to be mounted above the cylinder head level,
which my be a little tricky. On the mini I have the bottle mounted to the
n/s brace bar (removable GRP front). There is also an odd metal pipe running
along the length of the rocker cover. This links the bottom hose with the
heater outlet. Seems a little unnecessary, and it would get in the way of
rocker cover removal. I think I'll replace this with hose. I'd also like to
fit so chrome T-bars to the rocker cover.

Paul, saw your comment about the underseal. Yeh, I have some of that
finnigans stuff too. I'll slap a load of that underneath and keep the waxoyl
for the box sections. The fuel tank looks especially rusty underneath.

Another thing I noticed is that the pipe to the oil pressure gauge looks
like it's on it's last legs. I'd like to fit a nice braided hose. AFAIK the
gauge is the original. Are they smiths fittings? or Tim type? I expect the
block thread is the same as on the A series (1/8" NPT I think, or maybe
BSP). Is it difficult to get to the back of the gauges? Does the dash simple
unscrew and pull out, or will I have to work blind feeling up the back?

I'll scan some photos of the new MG tommorow hopefully and put them on the
web.


Scott


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