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TECHNICAL RESPONSES

To: MGS@AUTOX.TEAM.NET
Subject: TECHNICAL RESPONSES
From: VRHS43A@prodigy.com (MR JOHN H TWIST)
Date: Fri, 7 Jun 1996 22:10:49, -0500
Responses to several queries and comments of the past week:

WHEELBOX THREADS:  If the gentle application of heat to the hex or oct nut
on the wheelbox, then it is necessary to cut the nut off, allowing the hack
saw blade to run parallel to the threads, slicing a crescent from the nut.
Once the wheelboxes are out of the car (use a 3/16" socket to remove the
nuts from the rear plates), then use a thread file or a new nut to
"restore" the faulty threads.

CLUTCH HYDRAULICS:  Rebuild the master and slave at the same time - always.
If the slave is bad it leaks, if it leaks it's bad.  If the slave does not
leak, it's OK.  If the master cylinder leaks, it's bad -- BUT, it need not
leak externally to be faulty!  Commonly, a faulty master cylinder is first
noticed as the clutch re-engages even thought the pedal is on the floor.
Rebuild the master cylinder in place. DO NOT hone the aluminium cylinder.
Rebuild the slave cylinder after removing it from the bell housing -- it is
fine to hone it a bit.  Once THOROUGHLY CLEAN, reassemble with brake grease
(Girling SP 1280?), and bleed.  Bleeder out, use finger, for first five
bleeds.  Finger off, pedal down, finger on, pedal up, wait 20 SECONDS...
the repeat.  After five strokes, brake fluid will gush from the bleeder
hole.  Replace the bleeder (instead of the finger) and bleed several more
times, quickly.  All done.

ROCKER ASSEMBLY REMOVAL:  Design, engineering, and good mechanical sense
does not allow for the rocker assembly to be removed from the A or B series
engines without replacing the headgasket.  However, after EXTENSIVE FIELD
experimentation, I can assure you that removing the rocker assy poses no
thread to the head gasket.  But remove the 5/16 nuts on the studs, THEN the
3/8 head nuts.

STARTING an ENGINE AFTER a REBUILD:  Remove the spark plugs and spin the
engine with the starter motor until oil pressure is indicated.  THEN start
the engine.

DISTRIBUTOR DRIVE GEAR POSITION:  Find top dead center, number one firing,
by examining the rockers with the valve cover off, or by using one's index
finger on the #1 spark plug hole while pushing the MG forward (#1 fires at
the end of the compression stroke, which will blow one's finger off the
hole).   Use the timing marks to be certain the engine is at TDC.   Remove
the distributor and clamping plate.  Thread a LONG 5/16"-24 stud into the
centre of the distributor drive gear (find the stud in the air cleaner
assy, twin SU models). Remove the slotted screw holding the distributor
housing, and withdraw that part.  Pull the distributor drive gear from the
engine.  After THROUGHLY CLEANING AND GREASING THE GEAR AND HOUSING, drop
the gear back into the engine, keyway offset below horizontal, large half
of the driving dog upmost, with the keyway 9:00 to 3:00.  As the gear drops
into place, it will rotate anti-clockwise and set in at about 2:00-8:00.
The rotor should then face 1-2:00.

AMMETERS and VOLTMETERS:  Except in the RAREST of circumstances, the
ignition warning light indicates any problem with the charging.  AMMETERS
properly connected into alternator circuits provide at least two more
connexions which can corrode and cause the alternator to fail.   By some
driving gloves instead.

TWIN SIX VOLT BATTERIES:  The modern Group 26 Battery will fit into the
passenger box on the MGAs and MGBs and offer MORE ENERGY than the twin
sixes.  Of the many items which truly are NEW and IMPROVED, batteries are
among the top.  So much more energy can be stored in the same volume than
in the fifties.  The twelve volt batteries use modern technology.  The
sixes are still built the "old way" and are not improved.  I urge my
customers to use the single twelve.  Me?  I run twin sixes, positive earth,
with Lucas Helmet clamps -- I have no option -- I belong to the Positive
Earth Club.

GLOWING HEADLAMPS:  A glowing headlamp is a textbook case of a faulty
earth.  Find ALL the black bullet wire ends.  Brush them clean.  Fit NEW
Lucas female connectors (two - four or six way).  Add an extra earth wire
to one or more of these Lucas females.

OVERHEATING FRONT BRAKES - MGB:  Unless a rebuilder has incorrectly
re-assembled the calipers, the pistons will ALWAYS return.  A failure to
release pressure on the calipers is due to collapsed front brake hoses (not
a visual inspection), or an incorrectly adjusted brake light switch at the 
pedal.

IGNITION LIGHT OPERATION with a DYNAMO:  The ignition light is connected to
the battery on one side and the "D" terminal of the dynamo on the other.
When the dynamo either produces little or no voltage, or when it produces a
great voltage, the light will illuminate.  The former case is due to a
faulty dynamo or control box, the latter a faulty control box or faulty
earth connexion at the box.

OVERDRIVE on an MGB:  This coveted option offers "POM."  Peach of Mind.
After you run with one for a while, you'll never want to go back to std
4th.   But, there is little, if any, savings in engine wear or mileage.
MGB WEEPING CYLINDER HEAD:  The rule is, all rebuilt B series engines weep
between the block and head, between the 2nd and 3rd spark plug.  Some
actually piss.  To remedy this problem:  That center exposed head stud, RH
side, between #2 and #3 is the guide stud -- the hole in the head is 3/8
whereas the other holes are 7/16.  Clean out the stud hole in the head with
a 3/8 drill.  Polish that stud, at least. Ensure a chamfer at the threaded
hole in the block.  Chase the threads on the stud, nut, and block (3/8-18
and 3/8-24).  Ensure the head is planed to 0.001."  Ensure that the top of
the block is cleaned to a SMOOTH finish.  Fit the studs back into the block
with only about 5 lb-ft torque.  Place a THIN film of clear silicone, RTV,
sealant on the RH side of the head gasket.  Into that EXTREMELY THIN film,
place two strands of stranded, flexible wire about six inches long, twisted
together, along the outboard side of the gasket, between its edge and the
water jacket holes so that the thickness of the head gasket is effectively
increased by several thousandths.  Goodbye leaks.

SLICK 50:  If it was so great wouldn't SHELL or one of the giants buy them
out and capture the entire oil market?  I have the same view of octane
boosters and "lead additives."

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