Vehicle in question: 1967 MGB/GT
Problem: Overheating. Temp gauge reads normal when ambient temp is below
80F, but rises to 212 when sitting in traffic or travelling over 65 mph
if the ambient is 81F.
Things done: Flush and fill radiator, new thermostat, took out old
radiator to have it rodded, found it cheaper to buy a new radiator from
Moss. Still overheats. New water pump. Checked timing, mixture. Carbs
needed rebuilding, so I did. Still overheats. Check temperature gauge
with a calibrated thermometer - it is good to within 3F. Noticed there is
a flat spot on acceleration, so check mechanical advance. None present.
Pull distributor. Springs are different than the ones in my spare. Check
serial number - not an MGB distributor. So, I put spare distributor in,
which is for an MGB. Mechanical advance works, vacuum advance works.
Still overheats.
The only things I can think of now are:
mechanical advance curve not correct
blockage in the water galleries
timing marks are wrong
Are there specs somewhere on what the timing curve should be?
James Howard
Flagstaff, AZ
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