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Re: Being cool

To: "Larry Colen" <lrcar@red4est.com>, "MG list" <mgs@autox.team.net>
Subject: Re: Being cool
From: "Telewest \(PH\)" <paul.hunt1@blueyonder.co.uk>
Date: Sat, 11 Oct 2003 16:36:21 +0100
The factory V8 had the oil cooler below the plinth instead of above, but
then the rad extended below the plinth anyway so the oil cooler was still in
front of it.  An oil stat prevents over cooling in cold weather, whereas the
increased rows helps cooling in hot weather, only if you expect to
experience both frequently during the annual cycle would it be reasonable to
fit both, perhaps.  I know some people like oil stats, but hundreds of
thousands of these cars have run millions of miles without them with no
problem that I am aware of.  An electric fan is more efficient and more
effective than a mechanical one.  You are not likely to notice much from the
efficiency improvement but you will get much better cooling at idle or very
slow speeds in hot weather than with a mechanical fan, it does make for a
quieter engine too.  The fans have no connection with the temp gauge (sp) on
any system I have come across, but you can't rule it out, particularly with
French cars.  The factory V8 had the switch in the inlet manifold whereas
the 4-cylinder cars had it in the rad i.e. opposite sides of the thermostat.
Both were electrical which controls the fans via a relay (V8) or directly
(4-cylinder), the V8 and hot State 4-cylinder cars had twin fans, the rest
single.  Some (most?) aftermarket systems have a mechanical sensor which you
insert into the top hose and this has a tube connected to a variable control
which controls the fans.  The variable control allows you to set the point
at which the fans come on.  I have seen the top hose leak a little while the
engine is warming up on some cars with this probe.  I have also seen people
be paranoid with these systems and set them to come on as soon as the temp
gauge gets anywhere above N.  This can be counter productive and have the
fan running for much longer than it need to as it is trying to cool the
coolant lower than the thermostat will allow.  Factory electric fans
switched on and off about midway between N and H and this is perfectly safe.
Factory fans switched off with the ignition, whereas some other
manufacturers and after-market users have them wired to an always hot
(albeit fused) supply.  The former is safer.  Always have aftermarket fans
running via their own in-line fuse, don't be tempted to pick an already
fused supply from somewhere else, it could overload it.  If you use a relay
you can power the fans direct of a fused brown, which has a higher voltage
than the white and puts less load onto the ignition switch, and you power
the relay from a green (fused ignition) which means the fans won't run when
the ignition is off.  Many are worried about overheating in the MGB, but
unless the gauge does actually get up to H, or starts losing coolant, there
is nothing to worry about.  The factory used unshrouded pusher fans in front
of the rad but these are not very efficient, shrouded puller fans on the
back of the rad are much better - if you have the room.  Reversing the
electrical connections usually make the fan blow the wrong way, and the
blades also have to be on the motor spindle the right way round for best
effectiveness, the thicker edge of the blade is the leading edge and the
thinner the trailing, just like an aircraft wing.  Reversing the blade on
the spindle does *not* reverse the direction of flow.

Girling may not be a verb, but girning is.

PaulH.



----- Original Message -----
From: "Larry Colen" <lrcar@red4est.com>
To: "MG list" <mgs@autox.team.net>
Sent: Saturday, October 11, 2003 10:01 AM
Subject: Being cool


> One thing that I'm planning on doing is moving my oil cooler down
> below where it is, so that it is no longer blocking the radiator. This
> brings up the question of which Oil Cooler to use. I believe that I
> have the standard 13 row. Is it worth going up to a 16 or 19? If so,
> am I better off getting one from one of the "standard dealers" or
> taking an old oil cooler to a radiator shop and having them make me
> something special.
>
> Likewise, are the thermostatic controls for oil coolers worth the
> investment? Does running cold oil for a couple more minutes cause that
> much problem?
>
> I'm also considering going to an electric fan. What experiences do
> people have with them? Do any of the kits work better than others? How
> does the temperature control on them work? Does it wire in to the
> electric temperature guage?




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