Incredible But True Repairs (cont.)

special con-rod tool

Pinchbolt socket

Well that TD crankshaft would have quite a tale to tell if it were a sentient being.  In addition to being marked .010/.010 on one side of the number one & two throw, it was marked .020/.020 on the other side , but it was an obviously welded-up crankshaft because the main and connecting rod bearings were standard size as previously mentioned, and a  closer inspection revealed the center main thrust surface was also welded.  Whoo-eee that’s a lot of welding and grinding.  Of course it’s not the most radical crankshaft repair we’ve ever seen, because this one is:

 

spliced crankshaft

Seeing is believing

Seeing is believing. What you’re looking at is a reconditioned Laystall crankshaft for a 14 HP Lea-Francis.  It’s an archival photo from an earlier engine rebuild.  Incredibly the rear main bearing journal and flange are spliced into the rear counterweight, and we have it on very good authority that it ran like this for many thousands of miles before the subsequent regrind that you’re seeing here.   This is a remanufacturing tour de force, in my judgment.

 

repaired crank radius

Nice radius

We didn’t end up using it, but not out of disrespect for the anonymous engineer who managed to pull it off.   It is recorded in the literature that about 15% of the strength of an XPAG  crankshaft journal is imparted by the radius and in our experience many of the broken or soon to break cranks (as determined by a magnaflux inspection) we’ve seen have suffered at the hands of a machinist who was too lazy to dress his grinding wheel properly.  The radius on this Laystall crankshaft is quite a nice one, I think, however if you click on the picture for a really close look you can see it must have been the Devil’s work to grind it, probably because of the neatly spigoted into the rear counterweight immediately ahead of it..

 

Late Triumph Spitfire

Hello Spitfire

So let’s back up to  XPAG wrist pin clamp bolts  for a moment.  These are not accessable with a normal socket wrench.  There is a factory tool for the job (18G 327) which I’ve never seen, but a cut-down 3.8″ drive socket suffices pretty well.  we actually have two, a 5/16″ BSF socket to take the old ones out, and a 13mm socket to put the new replacement bolts in.  In the first photo above we have the piston clamped in the vice using a pair of aluminum spacers which hold the pin tightly without damaging the piston.

What we now know is last week’s con-rod bearing meltdown was probably a serendiptous event because the clamp bolts wern’t even tightened past about 15 foot pounds of torque out of the recommended 33 ft lbs. and when these let go the results are frequently catastrophic.

In other news, Butch got a move on today with the long dormant Spitfire 1500 which is recently arrived from Texas for some reconditioning.

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The Lady Was Innocent

MG TC

A final once-over

A favored MG trivia question is to name a seven letter work with all five vowels in it.  The answer is 1949 MG TC in the Sequoia Cream Livery like this one here, on its way back to Virginia soon after a 25 year sojurn in New England.  The current property of a retired member of the teaching faculty of Harvard University, it’s headed to the greater Washington D.C. area.  Butch is seen here giving it a final once-over before Mike Savage trailers it down there next week.

Con-Rod bearign failure

Wipe Out

Tracing an engine failure back to its route cause is always an interesting investigation.  The owner of a well presented MG TD MK II (TDC is the proper nomenclature, I believe) contacted us after the engine seized while his wife was driving the car, the failure believed to have been caused by inattention to the oil pressure gauge, what a pity with a relatively low number of hours on it after a rebuild by a well known “T” series specialist in Redding, Connecticut.  As you’ll notice, the number one connecting rod bearing and crank journal are pretty well wiped out.  The others didn’t fare well, either.

Intact main bearings

Exculpatory Evidence

But sometimes things are not the way they seem, and this the mains exonerate the lady. This is great stuff because the main bearings are in fine shape with no evidence of impaired lubrication due to lack of oil.  What we have is a fundamental mistake on the part of the installer, failure to ensure the crankshaft was properly cleaned before installation.  During the teardown we noticed that while the crankshaft was marked .010″/.010″ indicating main & rod journal size, the less badly damaged con-rod bearings were marked, and in fact measured up, as standard, evidence of a welded-up crankshaft which was not adequately cleaned after repairing.

 

Morgan on test

Not “T” series

The damage appears to have been fairly catastrophic to the rod journals, but it’s not the first time we’ve seen it, as a similar failure occurred on the Sequioa Cream TC when we replaced the crankshaft with a new one a number of years ago.  At that time replacement VP 252 rod bearings were still available in Vandervell VP2 trimetal material, and they were a good deal more durable. The standard bearing of the day was a white metal  VP 383, which was a good engine bearing in a time when one of the tasks of  engine bearings was to safely embed small pieces of debris that could damage a crankshaft journal.  When a similar post-installation washout occurred with the yellow TC the engine also ground to a halt (no pun intended)  because there was no imbedability with VP 2.  Unlike this one, however, the crank journals were nitrided and what looked awful polished right off, and a new set of VP 252s installed with no change in operating clearance.  Rest assured we never repeated that mistake.

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On The Road Again

MGB on test

Redlined

Late in the summer I trundled down to Rumson, New Jersey to retrieve a 1965, give or take, MGB which had been sitting in a heated garage since about 1985.

Thirty years of solitude will effect a toll on a piece of machinery, and although conditions for a long term hibernation were favorable, we still went completely thru the fuel & ignition systems as well as the brakes, which are now fully relined and rebuilt, as well rebushing the front suspension and replacing the king pins, which we do by exchanging the stub axle assemblies complete.

It’s sort of a cliche, of course, but once we got it out on the road the car felt as if it had just been put away the night before.  There are still a few floating gremlins.  What you’re reading on the tachometer isn’t engine abuse, the car was in 4th gear.  Very high tach readings are endemic to early MGB’s with electric tachometers.  When they show up we just exchange them for a rebuilt instrument.  We keep them on the shelf both as positive ground units , and also converted for negative ground.

Jaguar XKE

E-type on test

Also this week your scribe had an early E-type in his service bay which by now should be familiar to regular readers of these notes.  This car still has plenty of go, it’s current malady was a lack of stop.  Fifty plus years had finally caught up with the upper (rear) master cylinder through which Castrol GT LMA brake fluid was cascading pretty freely.

We have a connundrum with cars like this.  Normally when we work with brakes and front ends and lots of other stuff, we strip and clean the component and then run it thru the bead blast cabinet and chase the results with an application of primer and paint.

3.8 litre E-type engine

Pumpkin Orange

That’s a tougher call on cars like this where our primary consideration after safety is preserving originality, which this car has in abundance.  So in this case honing and a trip thru the immersion cleaner is more than enough enough physical remediation.  You can see this brake master in the lower left center of the photo just ahead of the Clayton Dewandre servo.  This is post- rebuild, the fact identifiable by the now shiny-looking Dunlop aluminum I.D. band.

BTW:  This is the original, untouched engine in this car.  If anyone would like to whack away at the reason why the cylinder head isn’t painted gold we have a free oil filter awaiting a correct answer.

V12 jaguars

Barn clean out

Patrick and I hoe’d out the barn over the weekend and juggled a few cars around.  We’re making space for the anticipated winter influx of longer term work that always starts showing up around this time of year.  I snapped this picture as he was pulling out this fairly rare black two door XJ coupe, which is running on the battery from the green two door coupe also in the picture.

These very special fuel injected XJ’s started showing up in 1975, but not until the side windows would go up & down at 100 miles per hour, according to the Norman Dewis who was Jaguar’s chief test engineer from January 1, 1952 onwards.

If there was ever a more handsome rear profile for a big four seater, I’ve yet to see it.

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Technique Matters

Butch adds coolant to an MGB

Butch shows how it’s done

A number of years ago a local boy bought a last of the line 1980 MGB which needed a cooling fan motor or two, which is a simple enough job. What was a bit more complicated for the owner was replacing the coolant that the car continued to lose.  Unlike the earlier cars, the 1977 on MGB’s lack a conventional radiator cap, routine replenishment is accomplished thru the expansion tank on the right hand side of the engine bay. like the MGC which appeared ten years previously.  Complete replacement of the coolant is effected thru a fill plug on top of the thermostat, and these originally were plastic and had a nasty tendency to break and shower the hapless attendent with a tsunami of hot coolant.  It’s been years since we’ve seen one of those, but we still keep a brass plug around just in case…

 

a melted oil filler cap

Bad Cap

This is a pretty lousy way to do it because not more than a trickle gets by the thermostat, and very slowly at that.  Our approach is to undo the top hose from the thermostat housing and pivot it 90 degrees up and fill thru the hose until the trickle is coming out of the ‘stat instead of trying to get in.  Well our friend decided to drive out to the shop so we could do it for him, and as I recall he showed up on foot about an hour late for his appointment, his car having expired on the grade out from Putney.

That car got some hot, as you might imagine, hot enough to melt the oil cap and that is in fact some of it on the rocker arm which was underneath it, too.

 

an MG TD engine about to come out

Engine out time

It’s been a week of MGB’s, four or five of ‘em depending on how you’re counting, and it’s been exceptionally busy for this late in the year.  So for a change of pace we decided to take an hour or two and haul the engine out of the MG TD MkII which the owner trailered up from Massachusetts on Monday.  While we understand it got a little low on oil, we know it doesn’t turn, which is interesting because even after its epic meltdown, the 1980 MGB engine did.

 

Sunbeam Alpine

The Sunbeam Alpine on test Monday

Now about those Corrigans from last week, there were actually three:   from the top of last week’s post, a trailer loaded with the most of the weight behind the axle is going to have a tendency set up an oscillation that will whip the tow vehicle back and forth quite violently.

When this happens standing on brakes is the wrong thing to do, you need to stand on the accelerator pedal instead.  If you don’t quite grasp the concept, try repeating the exercise on a table with a piece of string.

The second Corrigan was also the third.  As pointed out in the story, the leading brake shoe in the second picture was the wrong way around, but I also identified the car as a 1963 MGB, which it can’t be, because it’s a tube type axle (you can identify that by the hub) and those didn’t start coming into serivce until the introduction of the MGB GT in 1965.

A footnote:  this is the 200th consecutive weekly edition of This Week at The Shop

 

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