Technical Talk

Here we publish hints which may help you maintain or enhance the pleasure of driving your Morgan. Its success will depend on you, our enthusiastic Morgan technical types or home mechanics.  Any articles/photos are welcome as long as they are original and electronic (Word format). If you know of links to other good technical pages let us know so we can include those in our links section. Send your submissions to webmaster@morganownersclub.com.au .

Index

Of Sliding Pillars & Axles - John Merton

Morgan Plus 8 Front Suspension Spring Restraint - John Wroe

Morgan Front Suspension Bushes - Anthony Browne

Morgan 4/4 Series 1 -  Anthony Browne

The Standard Special Engine - by John Merton

Patent Prattles Series - John Merton

Morgan 4/4: Sierra 5-speed Gearbox Conversion - Tim Hurst

Dash Rocker Switch Fix by Geoff Williams

The Coventry Climax IOE Engine by John Merton

On a wing and a prayer? by Noel Bryen

Balancing HIF SU Carburettors by Colin Jones

Removing Play from the Burman-Douglas Steering Box by John Merton

Coachbuilding Timber Selection by John Merton

High Level Stop Light by Neil Hurst

Rear End Collision Risk by John Mott

Of Sliding Pillars & Axles

John Merton

So you thought Morgans had a sliding pillar suspension? John Merton provides food for thought in this paper.Click here to download a copy.

Morgan Plus 8 Front Suspension Spring Restraint

John Wroe

As an adjunct to Vern Dale-Johnson’s March 2008 EAR article “Long Distance Touring” and the enclosure “Rebuild Your Own Front Suspension” by Fred Sisson 1997, referred to as “THE INSTRUCTIONS”, John describes some additional tools useful to retain the road spring compressed and to guide the King pin during re-assembly. Click here to download a copy.

Morgan Front Suspension Bushes

Article on experiences and testing of Vesconite Hi Lube by Anthony Browne. Click here to download a copy.

The Standard Special Engine

 An interesting and thorough paper on the Standard Special Engine by John Merton. Click here to download a copy.

Morgan 4/4 Series 1 - Technical Notes

Technical notes for Standard Special Motor, Burman-Douglas Steering Box, Moss Gearbox, History, Components & Suppliers
By Anthony Browne, Morgan Owners Club of Australia. Click here to download a copy.

Dash Rocker Switch Fix 

Submitted by Geoff Williams

The indicators on Issy, my '69 Plus 8, had given up the ghost! Occasionally they could be persuaded to work by switching the hazard flasher on and off. 

You might think this is not a problem for a race car (who needs indicators on a race track) but she is fully registered and indicators are checked when you go to get a pink slip! 

The wiring diagram shows the power supply to the indicators runs through the hazard switch.  When the hazard switch is off and the ignition is on, power is delivered to the indicators. When the hazard switch is on, power no longer flows through the normal indicator circuit but instead flows to the hazard flasher circuit. 

The beauty of these older (late 60’s and 70’s) switches is they can be dismantled and internally they are very simple – just a few bits of copper and plastic. Examination showed overheating through a poor contact had melted a plastic component and the switch wasn’t switching! 

I enquired about a new switch from trusty Melvyn Rutter and found there was good news and bad news. The good news was they could supply, the bad news was it would cost £39 plus postage.  Now, as much as I want to keep Issy original, $150 for a switch was starting to sound a trifle beyond a joke. 

What to do? First option was simply to bypass the hazard switch and ensure the indicators had power supply. This was easy to do but what if I was asked to demonstrate hazard flashers at the next rego check? 

I decided if the switch is simple, a simple Plus 8 owner should be able to repair it. This was achieved by remanufacturing a small plastic rod (I used a plastic welding rod and drilled it). It was a fiddly operation but in the end it worked. 

So, if your dash switches fail don’t throw them away before first checking what’s happened inside. You may just be able to fix it and save a fortune! 

The Coventry Climax IOE Engine

(WHATMOUGH PATENTS AND OTHER MATTERS)

Submitted by John Merton

The Coventry Climax I.o.E., or rather O.I.S.E. (overhead inlet, side exhaust valve) engine used in early production Morgan four-wheelers has a number of Great Britain patents listed on a plate on one rocker cover. These, ascribed to Whatmough (Wilfred Ambrose Whatmough) are numbers 303592, 319810, 326454, 329340, 332523, 349460, and 373991.  They date from around January 1929 to May 1930.

 My interest in the above patents grew out of a statement in a book that the cylinder head was manufactured to a patented design by Whatmough.  With little previous interest in or knowledge of the origins of the I.o.E design, I (and friends I spoke to on the matter) assumed that Whatmough had invented the I.o.E configuration, as it was the essential feature of the cylinder head design.  Subsequently, an Australian historical automotive journal of good standing carried an article on Hudsons intimating that Hudson had invented the “F”-head design.  This claim had been included in a 1928 advertisement for Hudson cars.

 The matter triggered an examination solely to see, initially, which of the two had the stronger claims to having invented the I.o.E design.

The outcome follows.  It has led into fields much wider than just patents, and challenges and refutes entrenched Morgan lore in a number of areas.

 For much of the information on the Triumph connection (or more properly lack thereof as regards the particular engine used in Morgans)  my thanks to Antony (Tony) Cook, founder and past secretary of the Pre-1940 Triumph owners’ Club of the UK, and currently secretary of the Skoda and Tatra register in Australia.

BACKGROUND - the Hudson and Whatmough patents.

First,  neither Whatmough nor Hudson invented or patented the I.o.E. design.

 I.o.E. engines date almost to the dawn of motoring.  The earliest tended to have “atmospheric” or “automatic” inlet valve operation, based on the principle that gravity would assist the valve opening process.  Royce and Rolls-Royce cars before the “Silver Ghost” (except the V8 “Legalimit”) had I.o.E. engines, and they were well-established motor cycle practice by around 1910.

 Significant is their appearance in Hudson’s light car, the “Essex”, named after an English county, which had a four cylinder I.o.E. engine from around 1919 on, and was apparently quite a well-known sight on English roads in the 1920’s.  These cars were assembled for a time at  a plant on the Great West Road, Chiswick. Another make to use I.o.E engines in the 1920’s was Humber.

In January 1928, Hudson was granted a patent (US1656051, inventor Stephen I Fekete) for refinements to the I.o.E design.  The essence of this patent, which covered the arrangement of valves, head, cylinder and spark plug, was an inlet valve overlapping both piston and exhaust valve , so that cooler inlet gases could help cool the heads of the exhaust valves while still efficiently entering the combustion chamber.  The arrangement aimed at greater volumetric efficiency, higher compression without pre-ignition, higher rpm and more power, while still providing effective exhaust valve cooling.  The Patent also provided for spark plug location adjacent to the exhaust valve on the side furthest away from the piston, to spread the flame progressively from the hottest to the coolest part of the chamber, helping prevent pre-ignition.

 Hudson itself used a six-cylinder I.o.E. engine to this design for about three years in the late 1920’s, but later abandoned this in favour of side valve designs.  It was the smooth running of these later engines which made such a big impression on Rolls-Royce engineers in the 1930’s.

 The listed Whatmough patents cover, with a single exception, combustion chamber design, aimed at gas- flow, turbulence, and volumetric efficiency considerations.  While their listing on the valve cover might imply they are only cylinder head related, they also embrace gas-flow considerations affecting the cylinder block on engines with side exhaust valves.  Whatmough played around with curvilinear shapes (including relieving the bore) moving later to squaring off some faces in the interests of manufacturing convenience, the clear implication being that some of his theories didn’t amount to much if anything in actual practice!

 Some Climax engine valve covers also carry a plate stating “Whatmough  Cylinder Head”, leading to speculation that he may himself have manufactured these heads and supplied them to Coventry Climax.  The patent changes taken in the light of manufacturing experience tend to give some credibility to this speculation.

 Basically these patents (except for the one) mostly relate to the first, involving modifications or improvements to it.  A common thread is location of the spark plug over or adjacent  to the exhaust valve on the side away from the piston, for the reasons stated in Hudson’s earlier patent!  It is almost certain that Whatmough knew of the Hudson and other work in this field at the time.  “Motor Sport’s” William Boddy, and others have indicated quite a lively correspondence at the time in automotive engineering journals between Whatmough and Weslake (perhaps also Ricardo - these touted as the “big three’’ of cylinder head design, at least in the UK), concerning their particular theories.

 Whatmough’s patents are catholic in relation to valve configuration, the principles seen as applicable to side, T-head, and I.o.E., with one patent also specifying O.H.V.  In other words, the patents listed on the valve cover of the Coventry Climax I.o.E. engine are not specifically directed at an I.o.E. cylinder head configuration.

 The “exception” patent, number 332523, was for cooling passages, the idea being that if adequate cooling was provided for the “hot” part of the engine, i.e. the exhaust side, the inlet side would be overcooled, and vice-versa.  Whatmough’s approach, basically, was to provide for larger water passages on the exhaust side and smaller ones on the inlet side.  Once again, this patent covers both cylinder head and block.

 The Coventry Climax Connection

 According to a short published company history by Coventry Climax, and a separate published chronology of British Leyland, H. Pelham Lee, Coventry Climax’s founder, established a car engine manufacturing facility in 1904 called Lee Stroyer.  This evolved into Coventry Simplex Engines Ltd. in around 1907,  leading in turn to the foundation of Coventry Climax Engines Ltd. in 1917.

 The subject of our interest, the Coventry Climax I.o.E. engine, appears to have been first used in the AJS light car, from around August 1930. This, and the dates of the patents (up to May 1930), as well as Whatmough’s possible “crib” of that aspect of the Hudson patent relating to sparking plug placement, do make it tempting to speculate that the adoption of this engine configuration  owed something to the Essex example.

 The company’s Morgan connection in the 1930’s came about through the supply of an 1122cc four cylinder version of the I.o.E. engine for the production Morgan 4-4, which hit the market from 1936.  Early engines were claimed to produce 34 BHP at 4,500 rpm.  Some time in 1936, modifications were made to the design.  Reportedly, the earlier arrangement of distributor combined with  a chain-driven dynamo was changed to a separate distributor driven by skew gears, the dynamo was given belt drive, the cup and ball joint on the inlet pushrod and rocker was inverted, with the cup going to the top of the pushrod, the positioning of the oil filler was changed and the lower radiator connection was moved and enlarged.  Larger inlet  valves and a slight modification to combustion chamber shape boosted claimed horsepower to 36.

 The sideplate on the engines supplied to Morgan clearly indicates their origin.  It states “Specially made for Morgan Motor Co. Ltd. by Coventry Climax Engines Ltd.”

The Triumph Connection

Triumph first used the 4-cylinder Climax I.o.E. engine , in 1018cc configuration, from 1931 in its 9hp car. Subsequently Triumph adopted the design in both 4 and 6 cylinder guises for a range of its cars.

 There are two theories on the actual manufacture of these.  The first is that that Triumph machined and assembled them from rough castings supplied by Coventry Climax, the second that they manufactured them completely themselves given that they had suitable foundry and machine shop facilities spread over three factories, one in Priory Street, Coventry, another in Stoke Street, and the third the original “Gloria” works in Clay Lane, Coventry. Almost certainly the second was the case and this appears to be the consensus view.  The sideplate on the Triumph engines indicates they were made under a special arrangement with Coventry Climax, thus is quite different to the plate on the Morgan engines.

 Triumph used three small 4-cylinder versions of the Climax I.o.E. engine.  The smallest, of 1018cc, was used in the “9” and also, in slightly tuned form, in the early Triumph “Southern Cross” sports cars. The other two small Triumph engines, specified G10 and G12, were of 1087 and 1221cc capacity respectively.  The G10 engine developed a claimed 40BHP at 4,000 rpm, while the G12’s claimed figures were 42BHP at 4,500 rpm.  From 1934 on, both the G10 and G12 engines were fitted with water pumps. 

 Research by Tony Cook revealed no evidence that Triumph ever used the 1122cc version of this engine, even though several written works on Triumph make this claim.  For example, the late Michael Sedgewick, writing in “Vintage and Veteran” magazine, opined that this was the one motor probably not made by Triumph themselves but supplied direct by Climax.  Tony Cook believes however, that in this and other references the motor has been confused with the 1018cc unit actually used by Triumph.  (A parallel in the Morgan world is that at least three Morgan books, and several articles possibly using the books as reference sources, claim wrongly that the post-war Standard Special engine was fitted with a water pump).

 One Triumph model, the “Gloria Vitesse”, used tuned versions of the G10 and G12 engines. The smaller-engined 4-cylinder models had twin SU carburettors, consisting of one small bore side draft and one larger bore downdraft on a delayed linkage.  It is believed some early  Morgan owners may have privately fitted this, or a similar set-up, to their vehicles.

 The Triumph company ceased its involvement with Coventry Climax engines in 1937 when it completed the move to its own new in-house overhead valve designs.

 Crossley and Other Connections

Crossley used the Climax 1122cc engine in its 10hp cars from 1932 on.  The engine supplied to Morgan seems to have had the same basic internals as this engine but with slight differences in the block casting and flywheel/clutch, and with induction and sump arrangements more like those on the Triumphs.

It appears that Crossley ceased car manufacture in 1937, concentrating thereafter on commercial vehicles.  It was another company which, through a series of takeovers, finally disappeared down the British Leyland “black hole”.

 Climax engines were also used in a small number of Vale Specials in the 1930’s.

 Advantages /Disadvantages of the I.o.E. Design

The claimed advantages of the I.o.E. design were that it allowed larger valves than either side or OHV designs (the latter constricted by the narrow bore long stroke situation brought about by the RAC rating system), also better cooling around the exhaust valve because of more room for water jacketing.  Location of the spark plug near the exhaust valve enabled the flame to move from the hottest to the coolest part of the combustion chamber, helping avoid detonation, and the system was claimed to permit higher compression ratios, hence more power, than the norm for the period.  Hudson’s 6-cylinder engines, for example, ran at 6-1, about 20% higher than the norm for the mid-1920’s.  The engine supplied to Morgan in the late 1930’s had a claimed compression ratio of 6.85  to 1, also high for the period.

The big disadvantage was the heat range with which the spark plug had to cope - it had to contend with cool conditions under light load but also with very high temperatures under heavy load. Spark plug selection was a bugbear for motorists in the early 1930’s using the smaller Climax I.o.E. engines.  Hudson overcame this to some degree in its six cylinder engines by using the overlapping inlet valve, and also by fitting a water pump.  The Triumph G10 and G12 engines were also water pump-equipped from 1934 on, a feature lacking in the Morgan engines.

 Implications for Morgan Folklore

There are several claims enshrined in Morgan writ which are either incorrect or misleading.  What follows addresses some of these.

 Issue 1.  That Morgan used the same engine as in Triumph’s “Southern Cross”

 Incorrect.  Triumph did not use the 1122cc version of this engine.  Both its G10 and G12 engines were fitted with water pumps (from 1934) and there were some other differences in specification as well.

 Issue 2.  That Triumph supplied engines to Morgan under a licensing arrangement with Coventry Climax.

 Incorrect.

 When I raised this issue with Tony Cook he was most adamant and insistent that Triumph had never supplied Morgan with any engines, they would have all come from Climax .

In support:

 -the Morgan sideplates clearly state the engines are made by Coventry Climax - the Triumph engines have a quite different statement

-Morgan used the engines from 1936 to the outbreak of the War, while Triumph stopped using Climax engines from 1937      

-the Morgan engines are to a different size and specification (no water pumps)

-it is highly unlikely that Triumph would disrupt its own production lines (particularly after 1937 when they were geared to OHV engines) to produce an engine to a different specification to any it had used, for a separate company, to supply to a rival car maker.  Remember also that Triumph were operating at a loss for much of the 1930’s

Issue 3.  That Triumph owned Coventry Climax before World War 11

Incorrect.  I have been unable to find one tittle of evidence to support this claim.  Both the Climax-issued  history booklet and the British Leyland chronology make no mention of it.  In fact, the latter indicates clearly that Coventry Climax remained a separate entity until taken over by Jaguar Cars Ltd. many years later.

 One might ask how Triumph, with its history of loss-making through the 1930’s could have afforded to buy Climax.  Or who, when Triumph went into bankrupcy in 1939 it sold Climax, by then a highly profitable operation, to? Another question also is why Triumph would walk away from an engine arrangement with Climax in 1937 contributing to a situation of some stress for Climax (see later) if Climax was in fact a subsidiary?

Issue 4.  That Triumph (or somebody) must have made the engines for Morgan as Coventry Climax was too small.

Incorrect.  Coventry Climax had been manufacturing and supplying the passenger car and commercial vehicle industry with engines for many years.  In fact in 1937 it found the vagaries of car engine production left it with underutilised production capacity and moved to large-scale production of water pump trailers (complete with Climax engines). We are considering an operation which had the capacity to produce some 40,000 water pump trailers up to the end of World War 11. The engine sideplate also gives the lie to this claim.

Issue 5.  That the I.o.E. cylinder head used on these engines is the result of research by Whatmough and Weslake.

Incorrect.  Weslake is not mentioned in any of the listed Patents.  Some did have co-authors, however.  These were, variously, Findlater, Hewitt and White.

Issue 6.  That the cylinder head was manufactured to a patented design by Whatmough.

Misleading.  The distinguishing characteristic of this engine is its I.o.E. configuration.  The claim is misleading if taken at face value, ie Whatmough patented and invented this design.  Whatmough’s listed patents , some in collaboration with others, cover gas-flow/combustion chamber shape, except for one which covers cooling,.  They are not exclusive to the cylinder head, nor are they exclusive to the I.o.E. engine design.

In shorthand, the engine embodies aspects of several of the listed patents, covering gas-flow/combustion chamber design and cooling.

When did Climax Stop Car Engine Production?

By 1937, Climax’s car engine operation was under stress.  Triumph had been a major client throughout the 1930’s, and the ending of this arrangement would have caused financial concerns for Climax.  The direction of Crossley’s car making efforts was increasingly wobbly, and Morgan and other clients were small fry.

The published Climax version is that by the late 1930’s Leonard P Lee, then running the company, found that the natural evolution of the motor industry faced him with the need to look elsewhere for an outlet for the special types of engines which his father had produced for so many years.  In 1937 an opportunity occurred to consider a Government requirement for trailer fire pumps which would utilize two engines already available.  Two types of fire pumps were developed and large Government orders obtained.  (The two engines involved were both side valve designs - the smaller of the two is claimed to have been that developed for the Swift, a make which disappeared in 1930).

The publication claims that Climax stopped making car engines in 1937 (it doesn’t indicate precisely when that year) to concentrate on the fire pump contract.

But how does this accord with the continued supply of engines to Morgan into the first half of 1938?

Laban, in “Morgan: First and Last of the Real Sports Cars”, touches on the contract situation. He quotes from November 1937 factory minutes to the effect that given a delivery of a further 250 engines was in train, at a price rise from 29 pounds to 36 pounds, the company should look to seek an amendment as soon as the suitability of the  Standard  ( Special OHV) engine had been determined. However, according to Laban this engine had first been offered in 1937.  As, by design, it draws on parts from several of its contemporary Standard side-valve engines, it would appear to have been a relatively simply matter to ring it to production quickly, assuming Morgan had been able to take this route.

However, given that they had to see out the contract and were unable, apparently, to renegotiate the price suggests that Coventry Climax may have had them over a barrel.  The contract appears to have been lock-tight and the price escalation may well have been inserted by Climax at a time it was facing some uncertainties (perhaps before the fire pump contract?) and needed the cash flow .

But if they stopped making car engines in 1937, how did Morgan still get them?  As we have seen, certainly not from Triumph.

I would suggest a simple answer.  Common industry practice at the time was for the industry to “weather” engine blocks for anything up to eighteen months in the belief that this helped engines to “stabilize” by relieving stresses and thus made them more durable.. It is almost certain that Climax followed this practice.  The Morgan engines would have been assembled from castings already made.  The Climax claim therefore, is not strictly speaking incorrect but it is misleading.

Why did Morgan Move to the Standard Special Engine?

Although cost has been suggested as a factor (and the Standard engine was much cheaper), the real reason was that Morgan had no option but to look for an alternative engine. At that time also Morgan’s main competitors - MG, Singer and Triumph -  were all using full OHV designs, with Singer wedded to overhead camshaft operation.

Coventry Climax had opted out of the uncertainties of car engine production to concentrate on their fire pump trailers, and the option of a further contract  no longer existed for Morgan. Had such an option existed, Morgan may well still have switched engines, but  the Climax engine had simply departed from the equation.  

John Merton, c.2003. (NOTE:  This is a slightly revised version of an article which appeared in “The Morgan Ear”, May 2002)

 “The Autocar”, 2 October 1936

 “Morgan Four Wheeler Workshop Manual”  John Dowdeswell, circa late 1950’s.

 “Servicing the Morgan 4/4”  Bulletin based on Motor Trade data (addendum to Dowdeswell manual)

 “Morgan:  First and Last of the Real Sports Cars”  Brian Laban, Virgin Publishing Ltd., 2000.

 “A Short History of the Fire Pump Engine that Won Motor Races” released by Coventry Climax, circa late 1960’s.  Produced by Cogent Elliott Ltd., printed by WW Curtis Ltd.

 “Melting Pot of Britain’s Motor Industry”  Tom Northey, in “On Four Wheels”, volume 1 part 13, Orbis Publishing 1973.

“Thrilling New Limits of Performance”, advertisement for Hudson cars, page 35 “The Literary Digest” for September 1, 1928.

Balancing HIF SU Carburettors

By Colin Jones

Not having a go at your technician but I trained many of them when I was at BL who did not really understand the tweaks.  The HIF Horizontal Integral Float) is a very sensitive carb with a bi-metalic strip which trims the AFR (Air Fuel Ratio), There are no shortcuts, there are also many things that can cause EXACTLY the problem you have, here are the modifications and adjustments we used to teach, its was 30 years ago though  ;-) .

1.  Take off the carbs and turn them upside down, mark the lower float  bowl plate to carb body position with a felt pen (its possible to mess up the reposition) and remove the 4 screws and washers, remove the lower plate, let the O ring seal dry in air as it may expand.

2.  Inspect the bi-metallic strip that holds the jet in position if at  room temperature its not perfectly flat discard and replace it, note its used as part of the mixture adjustment and the 'notch'  must locate in the mixture screw pin, these can become dislodged.

3.  Check the float arm type, early ones were cross (+) section and  should be discarded as they distort, use the later (H) section which are much  more rigid.  Check the float height, this is critical. Look at the float from the side and you will see a U section moulded in the float, the LOWEST part of that U must be level with the aluminium body of the carb when it is held square and upside down and the float is under its own weight.  Use a straight edge or a drill shank to check this, a slight difference (+/- 0.025) will mess up all other settings, adjust by bending the float needle brass strip a little at a time.

4.  Rebuild the lower portion of the carb and turn to the correct way round.

 5.  Mark the position of the top vacuum chamber with the felt pen, you cant put these on wrong but it saves messing about later. Remove the 3 screws and carefully lift off the dashpot.

THERE ARE TWO TYPES OF HIF CARBS, THOSE WITH & THOSE WITHOUT ROLLER BEARINGS.

 6.  In the HIF dashpots that include a twin track ball roller bearing arrangement, this is to stop the piston sticking and should never give a problem, might be worth checking but its maintenance free.

7.  If the carbs have been overhauled your just doing belt and braces here but just look for wear marks in the dashpot (should not be any with the bearing system) but give it a clean out anyway.  The main reason is I want you to rebuild everything with ENGINE OIL, I know other cringe but thats what SU Butec and BL used in production, playing with oil viscosity is for later, lets just get it running!

 8.  Before topping the oil centralise the bearing, to do this you  rebuild the vacuum chamber and leave the dashpot damper out, put a finger in the venturi and lift the piston to the max lift and drop it, it should clunk with a metallic sound, this indicates a centralised bearing.

9.  Now fill with oil, to the bottom of the threaded area.  You should have retaining clips on the dashpot damper, lift the piston again (not so  high as to burp the oil out) and push the clips on the damper back into  place.  VERY careful use of a small screwdriver, do not scratch the  piston.  Screw on the damper.

 You can now base set the carb, turn in the mixture screw (on HIF's the screw is IN to richen, OUT to weaken) and then back it off two and a half turns.

 WITH THE IGNITION TIMING SET, start the car and allow to warm, turn in the  mixture screw a quarter of a turn (its + section so thats easy) until the engine  revs fall, now back out a quarter of a turn at a time until the revs increase,  stabilise and then fall again, from this position go IN one full turn.  The  mixture is now at the factory set.

For emissions you leave it just above the rpm drop off on the weak side, for performance its just above the rpm drop off on the rich side.

 THIS is now critical, when carrying out any adjustments to mixture you have  2 minutes, if you can’t achieve what you want in that time (its takes practice) you have to increase the rpm to 3000 for 30 seconds.  This is because the fuel in the float chamber becomes warm and the bi-metalic strip weakens off the mixture. You set it to compensate and when the cooler fuel arrives the mixture is wrong.  This is the main mistake mechanics make until they are taught otherwise!  So its a case of tweak, rev and hold, tweak, rev and  hold, etc.

A syncrocheck on the balance between carb air volumes, a recheck of  mixtures and a look at the exhaust (it should be like a puppies nose, wet and  dripping) and many happy hours lie ahead.

Sorry if that’s an egg sucking session for your mechanic but I have seen many well qualified people struggle. Set up correctly they give years  of trouble free service.

Please let me know what you find and what resulted from the above.

Good luck 

Colin

Removing Play from the Burman-Douglas Steering Box

Aside from a very few early 4-wheeler cars which had a reduction gear mounted halfway down the steering column, all Morgan Series 1 cars were fitted with a Burman-Douglas worm and nut steering box. Variations of this box were fitted to quite a number of contemporary British vehicles.

The system involves a thread, usually six start on Series1's, but sometimes five start (mainly left-hand drive), machined on the end of the inner column, carrying a bronze nut.  Right hand drive cars have a left-hand thread and vice-versa.  There is a hardened steel bush screwed into the top of the nut using a special process.  A peg at the end of the “L” shaft at the top of the rocker shaft engages in this bush. As the inner column turns, this peg transmits the up and down motion from the bronze nut via the rocker arm, to the steering drop arm attached to the bottom of the rocker arm shaft.  The drop arm is attached to the rocker arm shaft via a splined shaft and a pinch bolt. (NOTE: some cars may have been subsequently modified).  The shaft of the rocker arm rides in two bronze bushes, the top one of which has a diagonal cut for about three-quarters of its length to provide clearance for the bronze nut.

The only provision for adjustment is for end float, and is via two large thin nuts at the top of the column under the steering wheel which bear on a ball race.  The bottom of the inner column is free-floating, location being provided by the bronze nut, which is a sliding fit inside the box casing. The system on the Series 1 cars, with the common six start worm, gives one and three-quarter turns lock to lock.

This steering box continued in use, with some minor differences, on the Plus 4 cars, from 1950 up until around the 1954 season. It was then replaced with a Cam Gears Ltd steering box, which continued in use on all Morgans up to the advent of the Gemmer and rack and pinion systems. The Cam Gears box, while externally somewhat similar in appearance to the Burman-Douglas, is quite different internally. A cam and peg design, it is nothing other than the familiar old Bishop cam device, actually an earlier and cruder invention than the Burman-Douglas which it replaced!

The Burman-Douglas box can only be tested for wear properly on the car, ie under load, all connected up, with the wheels on the ground.  First, make sure there is no end float, and that the box is securely located and fastened.  Next (making sure there is a container to catch the oil) take off the end and top covers on the box and have a helper juggle the steering wheel while you (the “foreman”) check for play between the worm and the nut (ie for wear in the thread) and and between the nut and the side of the box. Check also for wear in the bushes (ie movement in the rocker arm shaft).  It is extremely unlikely that there will be any wear between the peg and the hardened steel bush in the top of the bronze nut.  If you are desperately unlucky, the bush may be loose in the nut, in which case I suggest  that you look for another nut, as I am still struggling for a way to make these stay permanently tight again.  The drop arm must also be tight on the bottom of the rocker, of course.  Note that there is an oil seal above this, usually of rope or felt, held in place by a washer, with box housing peened over to secure it.  This seal can be replaced with a modern neoprene one.

Something to watch for is that some replacement nuts are undercut on their topsides where the steel bush goes.  If you strike one of these, the peg can jump out of mesh when the wheel is turned, and you will have either to add an adjuster screw to the top cover to hold it down and/or pack out the bottom of the rocker arm for the same effect.

Address wear in the thread as follows.  Clean the nut thoroughly (Prepsol or similar)then tin the inside of the nut lightly with solder.  Grease the thread on the shaft with a good axle grease (don't use WD 40 or similar as they may well flash) and screw the nut on, about halfway along.  Melt babbit metal, heat up the nut, and pour the molten babbit metal down the bush hole, rotating the shaft until metal appears at the end of the nut.  Keep rotating the shaft as it cools down to prevent binding.

This will get rid of the play in the thread, but note that the effectiveness of the repair may be limited if the thread on the shaft has much “hourglass” wear on it.

Play between the nut and the side of the box is addressed similarly ie by building up the sides of the nut with babbit metal and machining to be a tight sliding fit in the box.  Addressing other areas of wear, eg in the drop arm shaft bushes, should be straightforward.

On reassembly, “work” the bits together using  moly compound and clean up thoroughly – remove all metal “dags”, filings etc.  Best to assemble and disassemble several times to ensure everything is scrupulously clean.

I have found the above effective in reducing play from around eight inches at the steering wheel circumference to around three quarters of an inch.

A note of warning – cultivate smooth driving habits and don't “yank” at the wheel. Never, on any car, try to operate the steering with the vehicle stationary.

By John Merton (based on an article first prepared for “The Morgan Ear” in 1990)

Coachbuilding Timber Selection

By John Merton

Background

Coachbuilding, in shorthand, is the practice of making a vehicle body by applying metal (or other) panelling to a wooden frame.  Morgans have nearly always had a coachbuilt body, and it has  been both the delight and despair of generations of owners.  The despair comes principally from the nature and type of framing timber used. 

Desirable properties for a framing timber are strength, resiliance/recovery, toughness, flexibility, and impact resistance. The timber traditionally used, indeed since Roman times, in Eurpean coachbuilding is the European Ash (Fraxinus excelsior), although reportedly some expensive bodies have been framed in mahogany.  In the USA, claimed framing timbers have included American white ash (Fraxinus americanus), closely related in characteristics and performance to European ash, spruce, hickory, and white oak, although coachbuilding went into considerable decline after the late 1920's as manufacturers moved to all steel body construction pioneered by Budd. 

In Australia before World War 11 there was a significant coachbuilding trade the length and breadth of the country, mainly using locally-sourced indigenous hardwoods.  Most cars were locally bodied on imported chassis. 

The Despair 

Despite the somewhat extravagant claims sometimes made for European ash, its performance is by no means outstanding, while its ability to resist racking (the tendency for the timber to compress under repeated movement, leading, for example to loose joints) is poor and its susceptibility to rot is legendary. A UK restoration specialist once said to me in an unguarded moment “It's a lovely timber to work, but it's the most rottingest timber known to man”. The British Handbook of Hardwoods (HMSO 1980)states, in relation to use of this timber in road vehicles, that it should be used with care on account of its lack of natural durability. 

The problem was recognised in the hey-day of British coachbuilding, one practice being to use oak instead of ash for the sillboards (those on the chassis rails)  because of its superior durability, despite its propensity to split. Since the mid-1980's the Morgan Company has been soaking its body frames in a copper naphthalene solution to improve durability.  However, be warned such treatment only has a finite life. 

The real reason European ash is used as a framing timber is because the trees are widely dispersed across Europe, the timber is in good supply, and it has good working properties.  However, in fairness, it must be said that in terms of flexibility, impact resistance and so on, there are few if any available indigenous substitutes in Europe. 

Better local timbers 

When I first developed an interest in coachbuilding in the early 1960's, there were still a few old-style coachbuilders around, and local libraries still had some technical training manuals on the subject.  The advice from both areas was that Australian timbers constituted the half dozen best coachbuilding timbers in the world at the very least.  The preferred timber was spotted gum, closely followed by blue gum then some other Eucalypt species and coachwood (Ceropetalum apetalum). 

Some old anecdotal evidence, from both the vehicle and boatbuilding industries, supports this. I have been told that the framework on the small numbers of completely built up expensive vehicles imported before the War generally failed to match, in either performance or durability, their Australian-bodied counterparts.  Also, boat restorers on the Murray River have told me that   imported wooden hulled vessels for the river trade in the 19^th and early 20^th centuries often lasted as little as 3 to 5 years whereas some Australian timbered hulls are still basically sound today. 

The contention is backed further by performance data.

Performance Data

Durability. 

Australian timbers are classed into 4 durability grades, Class 1 being heavier timbers suitable for use, untreated, in the ground or under water, class 2 and 3 timbers being suitable for outdoor use, while class 4 timbers are classified “non-durable”.  Class 4 is a catch-all.  Most of the above Australian timbers are in classes 2 or 3. Tasmanian oak is cclassified class 3 or 4 depending on the least durable timber in the particular mix, while coachwood is classified class 4.  My experience of European ash is that it is far less durable than either of these timbers, and would only enter class 4 due to the “catch-all” nature of this category. 

Related Issues. 

Most Australian hardwoods are hard and more difficult to work and shape than European ash.  However, coachwood is a lovely timber to work with. Although they glue well with appropriate modern adhesives, some older types of adhesives may be less successful. Joins should be pre-drilled and screwed, using stainless steel or phosphor bronze screws – it is too easy to turn the heads off brass screws, and plain or even zinc or cadmium plated screws should not be used because the natural oils in some of the timbers may break down the coatings.  

Preferably, treat the completed frame with an anti-fungal preparation, eg a copper naphthalene based product or one of the two pack products used in the yachting industry. Also I recommend painting the frame after the preservative soaks in and dries. 

Suitable timbers are available, seasoned, from specialist timber suppliers.  Some are used widely in the specialist furniture trade.

John Merton c.2005 

( Based on an article which appeared in “The Morgan Ear”, April 2002)
(Special thanks to Boral Timbers for assistance with performance data)

High Level Stop Light

Those of you who have attended the ‘Best of British’ weekends in Canberra may remember a yellow 4/4 that was shunted up the back by a tin top while out on one of the runs around our countryside. I believe the tin tops excuse was that he didn’t see the brake light of the Morgan. I decided then that when I restored my ’67 +4, I would fit a third stop light where it could be seen. In the event although I incorporated the wire for the new stoplight in the loom, I never got around to actually fitting one.

Neil's high level stop light looks completely in keeping with the Morgan	Detail view of the mount

I had been mulling around the problem of how to fit the light such that it could be seen over the top of the suitcase when we used the luggage rack and yet didn’t appear to be sticking up above the spare tyre like a trifid at other times. Then the penny dropped – lash it to the tyre with a leather strap normally and then add a further length of strap to attach the fitting to the suitcase as needed. Out came the tin snips and the result is as you see.

Materials you will need are

• A stop light (mine came from Supercheap Auto $2.50 on special).

• A piece of 1.5mm thick aluminium; 26 cm long x 9cm. wide (slightly more than the diameter of your chosen light).

• A piece of thin rubber to pad the finished base from the tyre.

• Half a dozen pop rivets.

• Some suitable electrical wire.

• A rubber grommet of a size to take your wire

• A leather belt about 3cm wide to attach the fitting to the tyre (Mine came from the throw-out table at Target $8)

• A longer leather strap of compatible width to go around the suitcase.

• Araldite and contact adhesive

• Etch primer, primer and top coat.

Scribe up the surface of your piece of aluminium as per the attached diagram. Cut out the curve of your stop light at one end; drill this for the stop light attaching screws, the hole for the grommet and the rivets. Bend up this end to about 60 degrees and then remove it from the stock. Cut a piece from the centre of the tongue the width of your leather belt and slightly longer than the tongue to allow the belt to fit snugly beneath the piece carrying the stop light.

Take the balance of your piece of aluminium and, placing it over your spare tyre, form it to shape as the base with your two hands. Mine is about 50/50 sidewall to tread. Place the piece which will carry the stop light in a suitable position on the base, adjust the angle, confirm the leather strap will fit between them without binding and mark out the positions of the rivets. Drill, Pop rivet and Araldite the two pieces together. Feed the leather strap through the assembly and around the tyre; mark out the strap and assembly for riveting, and cut the strap to length. Drill the assembly and the strap as marked. Prime and top coat the assembly but not the underside. When completely dry attach the strap and the stop light to the assembly remembering to use the grommet to protect the electrical wire. Cut the piece of thin rubber to the size of the base and glue with contact adhesive; this will protect the tyre from the rivet heads.

Wire to the loom with a suitable weatherproof plug in parallel with the existing stop lights, strap it on, test and have yourself a beer.

Neil Hurst

Rear End Collision Risk

John Mott

 Have you ever considered what would happen in an accident if another vehicle collided with the back of your Morgan?

In anything other than a minor bump there is a good chance that the petrol tank would be punctured with a consequential high risk of fire quickly engulfing the car due to the escaping petrol igniting.  This event is likely to happen due to the close proximity of the tank to the bracket that carries the hand brake mechanism on the differential and the mounting of the tank onto wooden boards with only a few securing bolts.

The following pictures show two occurrences where the tank has shifted forward in a collision and been punctured on the hand brake bracket.  One was a partially oblique sideways impact and the fuel fortunately did not ignite, The other ignited instantly and the entire car was engulfed in flames within two seconds with the occupants only just luckily managing to escape and avoid incineration despite jammed doors.

 

The best preventative for this scenario would probably be to fit a fuel cell in the tank as used in racing cars.  This is a costly solution and presents problems with the fuel gauge sender.  However, there is a simple modification that can be made which may help to minimise the risk of the fuel tank puncturing on the hand brake bracket and this is to fit a reinforcing plate on the tank to spread the impact.

 

The fuel tank on my 4/4 is just under 8 inches in height and I found a piece of 3 mm steel plate and cut a piece 11 inches by 6 inches which when bent into a U shape gave a return of one and a half inches top and bottom.  I rounded the corners to prevent them from puncturing the tank.  1/8 or ¼ inch plate would probably offer more protection, but 3mm was all I had on hand and it was easy to bend.  After painting the plate I cleaned the tank and attached the plate with some silica sealant.  So far it has stopped in place and hopefully will provide some deterrent to the fuel tank being punctured should the unthinkable happen.

This modification now gives me some peace of mind when I see in the rear vision mirror a monstrous four wheel drive tailgating me with the apparent intention of climbing into the rear seat.

 

John Mott