At Sports Car Restoration, Plainville, Connecticut

This shop has been pretty busy the last few years, although the last few days have actually given us a little breathing room, so when the owner of the completely gutted, very low milage 1275 Mini Cooper “S” which has been sitting on saw horses in the barn called Wednesday, the timing couldn’t have been better to get something done about it.

It seems he has a relationship with Sports Car Restoration of Plainville, Connecticut, and Patrick and I decided it was high time for a field trip.  This is a very impressive shop with a particular specialty in BMW’s, but there were others, and it was readily apparent that while their paint work  was impressive, their fabrication skills are absolutely first drawer, top shelf stuff.

Fits nicely in a pickup truck

In the picture above, Matt McGinn and Nate Williams and crew (that’s Patrick back, left) can be seen admiring their new work piece.  Not seen here is another of our mutual client’s cars; a rear-engined BMW 700 coupe with, I believe a horizontally opposed two cylinder motor, and my limited reading on it suggests that it is the car that saved BMW from oblivion in the late ’50’s.  It was obvious these guys really know what they’re doing.

Wrong Way Corrigan

Meanwhile, things are still moving along in MG TD World.  In the process of sorting thru a number of issues, some long standing and some recently installed, Butch noticed that the oil gauge flexible hose executed a nearly perfect 360 degree loop. Unusual.  Also, the copper pipe from the bulkhead to the gauge was installed backwards.  How do we know this ?  Well, the wrong end of the pipe is illuminated here by Butch’s blue flashlight and more or less directly below it is the threaded abutment of the gauge for the pipe.  Take note: There’s a small tit at the top of the threads, around which a small leather washer is usually found (our cars are analogue, not digital).  This is the sealing joint between the flat pipe nipple that was at the other end of the pipe, and the instrument. The Bad Boy under the glare of Butch’s flashight has a tapered end meant to engage the reverse taper in the flexible hose.  Why can’t we ever get away with this stuff ?

Right & Wrong

O.K. here’s another: An XPAG engine has a hydraulic timing chain tensioner to take up the slack in the chain, as you can see here.  Unlike it’s later British Motor Corporation Breathern, the MGA’s &  MGB’s and also Austin Healeys, it doesn’t have a ratcheting mechanism to retain the relative position of the guide slipper, and over time as the chain stretches these engines can develop a gently knocking at the front of the engine at idle as the chain slaps the slipper back into the housing.

XPAG oil pan threads gone missing

Many years ago Rick Smith (formerly of Automotion in Allston, Massachusetts) told me how to counteract this phenomena by putting a leather washer over the shaft of the slipper, as you can see here.  I make them out of a belt I long ago outgrew.  Also of note is the oil thrower installed backwards on the cam gear.

And here’s another:  The badly damaged threads on the oil pan of this formerly “rebuilt” engine.  There’s nothing worse on a fresh engine than an oil drain plug that won’t seal, which was sure to be our fate if this condition had gone unnoticed.  It didn’t, and it’s gone out for repair along with our specially made 20 X 1.75 millimeter thread cutting tap.

More news next week.

Good teeth & Bad teeth  (click the pic. for more)

Lea-Francis built a very fine twin cam pushrod four cylinder hemi engine, which in 1767 cc form was  campaigned in the Connaught Grand Prix race cars of the late 40’s.  However Lea Francis bought-in their gearboxes  from Armstrong-Siddley, and in its way, it’s a very fine transmission, too.  We have been tasked to overhaul a MkIV gearbox from a 2.5 litre LEAF, and fortunately it came with abundant spare parts which we are now sorting thru.  BTW: I believe that the MKIII unit used double herringbone gears.  I won’t digress on that topic here, but you can look it up.

Thursday: Patrick assembles another XPAG engine

The 2nd gear pictured above on the left came out of the 2.5 litre.  It has beautiful dog teeth, which are the pointy ones on top that engage the sliding synchronizer hub to lock it to the TX mainshaft, but the beveled gear teeth are pitted.  The gear on the right has very nice gear teeth, however the dog teeth are rounded off a lot more than we’d like to see, so we’ll dig a litle deeper in the spare parts bin.  That’s Patrick’s sketch underneath them on our cast iron surface table.

What’s wrong with this picture ?  (Generator removed for clarity)

Every so often someone brings us in a rubber bumper MGB with a complaint about heavy steering.  This is usually the result of the engine mount brackets, which are different from chrome bumper cars, having sheared, and that drops the catalytic converter on top of the steering column.  We once had one where a long period of subsequent use had cut a groove thru about  half the diameter of the column, but no harm, no fault I guess.

We never drove the car, and the customer never complained, but Butch thought the front engine mount of this TD seemed a little soft and decided to dig a little deeper.  That’s an engine mount bracket bolt hitting the steering column coupling flange.  The fix was a new mount.

Back to the matter of those broken MGB motor mount brackets for a moment.  It’s one of the few aspects (besides engine output) that didn’t get better on those cars thru evolution, even though it is probably tied to the engineering for the handful of V8-engined GT’s which were built ’73-’75.  For years we kept two and a half  sets of mount brackets on hand because almost every car we were seeing needed at least the left hand bracket, probably because of the torque load.

The past (we hope) as prologue

The current temperature is right around 20 degrees below zero (that’s fahrenheit if you’re reading this in a metric country),  and January 25 was the last day it was above freezing.  Right now our snow cover is approacking waist deep, but more is forecast later today so maybe we’ll get there.  So glad we’re not in Boston where they’ve gotten seven feet over the last month.

Here’s a picture from last year courtesy of the Wishful Thinking Department: Butch out for a spring road test in a Sports Car Services prepaired (meaning very fast) Morgan +4.  Spring’s coming, we hope.

Close Work

We’re doing an upstairs/downstairs MG TD routine just at the moment.  I’m prepping an engine for assembly and Butch is fettling another car upstairs.  It is a not unattractive red with red upholstery, just needing a little titivation to be a useful and reliable companion.  At the back of the car is a clever owner-engineered intervention ensuring reliable fuel delivery by inserting a standpipe above the 3 inches of muck in the bottom of the gas tank, while up at the front we elected to replace the waterpump on which the bearings supporting the wobbly impellor shaft had indicated their intention to sign off soon.  This is a simple job which is usually only complicated somewhat by the effects of 30 or 40 years worth of corrosion between the screws which hold the fan blades on, and the pump pulley spacer thru which they have to pass.

XPAG TD in initial paint

Butch snapped off the heads of all four screws, about what we expected, and he can be seen undercutting what’s left with the Dremel tool in order to remove the spacer and wind them out of the waterpump impellor shaft flange.

Meanwhile, downstairs I’ve been getting the TD Mk2 engine from late last fall ready for assembly, it having recently returned from the machine shop.

Bad Match

Saved by Pins

You may recall that we last reported out on this engine in November  (November 14  This Week at The Shop: “The Lady was Innocent”) when at that time the owner strongly believed that his engine failure was caused by his wife running it out of oil.  However the forensic evidence  completely exonerated her, as the main bearing shells were  unscathed but the con-rod bearings had been destroyed by the swarf from a regrind washing out of the apparently uncleaned crankshaft.

That this engine ever ran at all was miraculous, because in addition to the bearing failure, the cylinders had been rebored but never honed to finished size, thereby effectively destroying the pistons, too. But even more amazing, really, was the fact that the #3 con-rod utilized a bearing cap from a different engine and the upper & lower bearing inserts were offset on the parting line between the cap & rod.

Still Snowing Here

This amounted to a zero clearance situation where about .002″ would have been called for.  Go back and click on the first thumbnail photo for closer examination of the con-rod on the left.  What’s notable is the continuous machining around the parting line between the rod & the cap.  Compare this to the con-rod on the right, the #3 rod. Here there is a pronounced step at the parting line and the fix, performed by the same machinist last seen here taking a heavy cut on a Laystall-manufactured Lea Francis crankshaft a couple of weeks ago, was to open out  the bolt holes in the cap slightly, dowel pin the rod & cap for location, and machine it round again. A small act of genius.

Now we have something we can work with, and adding  the recent benefit of balancing, this ought to be a pretty sweet running engine.  We’ll find out in about six weeks when the glacier begins to recede again.

What’s wrong with this picture ?

Over the years much loud noise has been generated about the supposed deficencies of Lucas electrical systems, mostly passed along by the ignorant to the ill informed.  To this Jackals’ Chorus I would pose this simple question:  Please name even one Japanese car with its 50 year old electrical system still intact and working?   O.K.  I thought not.

There are some simple rules for understanding Lucas wiring (it also helps if you’re not color blind).

So here are the basics:

Mike & Butch tie down an E-type

Black is Ground   A.K.A. “Earth”, Letter “B”

Brown is Battery,   Hot all the time,  Letter “N”

White is Ignition  (also electric fuel pumps),  Letter “W”

Green is Switched thru the Ignition & Fused,  Letter “G”

Blue is the Headlight circuit, Letter “U”

Almost tied down

Red is the Parking Light circuit, Letter “R”

A green wire might have a black stripe if it goes to the temperature or fuel sending unit, but green with white is RIGHT, and green with red is the left turn signal.

Now we’re ready to address the question posited by the first picture.  Green wires in a 4-way snap connector common with black wires is a dead short, but not to worry because it’s fused, and this raises another point.  A 17/35 amp fuse is a ‘slow blow’ fuse.  It handles 17 amps continuously and will accomodate a temporary 35 amp surge, such as when you turn  the heater fan on when the wipers are working.    Replace it with a 35 amp Buss fuse and it becomes a meltdown.  However no worries either way here, because the heater switch didn’t work anyway !

B.T.W. : That yellow band around the oil gauge hose means it’s an original Smith’s hose, and that means this one is at least 40 years old.    Best to replace ’em when you see that, because over time they get very brittle and once they crack from the engine flexing you can lose five quarts of oil in just a minute or two.

Broken baulk ring

Here’s the broken baulk ring which Patrick fished out of the four synchro transmission of his MGB GT last week.  It’s split is just slightly to the right of the top ear of the baulk ring (click on the picture for a closer look).  It’s an unusual event when anything breaks in one of these transmissions, but there you have it.  At last report the car and its owner were in Texas headed for Arizona, after stopping in Tennessee to replace the fuel pump.  Best to carry a spare !