MG Car Club of South Australia
MGC NEWS
MGC conversations with Richard Mixture, July 2018
There wasn’t a part number on the old
clutch, so after some searching, a Tru-
flow fan clutch TFC137 was found that
suits GMH and Nissan. The height was
60.5mm. The fan seat on the clutch
allowed the fan to sit closer to the en-
gine giving 23mm gap between the fan
and radiator core but only 12.5mm be-
tween the clutch body and core which is
not a lot. In other words the clutch body
protrudes through the middle of the fan
and is closer to the radiator core than
the fan itself. You have to make sure
your engine mounts are in good condi-
tion!
MGC fan clutches
H
ello again, it’s Richard here. Now,
for an engine to run effectively it
needs to operate at the correct tempera-
ture. When the engine coolant is cold
its flow through the radiator is restricted
by a thermostat and when it gets too
hot, the thermostat must be open and a
fan helps air flow through the radiator to
cool it. All of these bits must be working
correctly if you’re going to have fun in
your MG.
Now, I’m sure all you MGCers reading
this will think I’m trying to tell you how to
inhale eggs, but if the old six pot lump of
cast iron gets hot it won’t like it. Well,
that’s what happened to that nice young
Register Co-ordinator, his engine got
hot and spewed coolant everywhere!
Taking a look at the original factory fan,
the distance taken by the original spacer
and metal fan leaves a similar space
between the fan and the radiator core.
The original fan spacer is 26mm thick
and the fan from the mounting surface to
the fan blade edges is also 26mm. Add-
ing these two together and subtracting it
from the 73mm distance between the
water pump flange and core leaves a
21mm gap, 2mm less than the modifica-
tion above.
The suspected culprit was the fan
clutch. Now those readers that are ex-
pert on matters dealing with MGCs will
know that MGCs don’t have a viscous
clutch that operates the fan. So why is
there one on our nice MGC Co-
ordintor’s ‘C’? Well he answered that
question by saying the modification
“sounded like a good idea at the
time” (2003) and anyway Bruce did it.
You know, that nice old Queenslander,
Bruce. With the engine idling, the fan
was checked by carefully inserting a
rolled up magazine into the blades and it
was easily stopped indicating there was
no oil in the fan clutch.
The other modification that is needed is
to drill two extra holes in the fan clutch
mounting flange. Fan clutches are nor-
mally mounted to the water pump flange
with four bolts. The MGC water pump
pulley and fan are mounted using only
three bolts. The original spacer can be
use as a template to drill these extra two
holes. One might wonder if the saving
of one bolt was a cost saving measure
imposed on Abingdon by BMC account-
ants?
Now, many of you will know that the ‘C’s
six cylinder engine is a long one and
there’s not a lot of room between the
water pump pulley and the radiator core.
The fan and clutch has to fit in a space
of only 73mm.
The length of these three bolts is critical
in order to fit behind the clutch mounting
flange and its body and still have
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