Elliott Montagu’s 1927 Triumph N model restoration – Part 6

The next thing to do was to set the timing.

The “Instruction Book” says to set the points breaking with the piston 7mm before TDC and ignition lever fully advanced.

VMCCUK old Triumph expert, Peter Cornelius, (cornelp@xtra.co.nz or peter@triumph.gen.nz ) recommended setting the timing at full retard on top dead centre. He maintains that the fuels we use now are so different to those used in the twenty’s that the tuning figures are no longer relevant. With the points breaking, the piston at TDC and the lever in the fully retarded position it is only necessary to advance the lever until the engine sounds and pulls OK. Not very scientific but apparently it works.

The timing was set and with a couple of mates watching I kicked it over. It didn’t start because we had set the timing with the lever in the fully advanced position! The timing was reset and amazingly the engine fired and ran on the first kick. This was quite a moment for me. Perhaps in the fifties, after being thrashed around a paddock for years the bike was discarded. The engine hadn’t made a sound for maybe sixty years and there it was running again with that old fashion characteristic exhaust note.

The valve timing was obviously out as the engine was blowing back through the carby. The valve timing was altered by one tooth and that fixed it. (These engines don’t have valve overlap).

There were a few small problems to fix. The petrol cock fitted is a tapered rotary type and it was leaking about half a cup of fuel overnight. Lapping with polish got this down to about half a teaspoon overnight. The difficulty in seating the needle valve in the float chamber is apparently common to these carbys but it appears that once the engine is running it’s not a problem. I have tried lapping the needle in, making a new needle and attaching a short rubber tipped needle from a modern carby to the needle. This didn’t work because when the diameter of the short rubber tipped needle is reduced to fit, the flutes disappear and the fuel flow past the tip is reduced.

The oil system on this engine is interesting. It is a total loss system. Oil is carried in a tank integral with the fuel tank and is delivered by a hand pump on the tank or alternatively by a dripper type system that is driven off the end of the crankshaft by a helical gear. This system was intended to be the primary system and even though a sight glass was incorporated the hand pump was retained because of customer distrust for the automatic system. We had several goes at making a helical gear which drives the automatic dripper but it was not successful. The shaft on which the gear is fitted runs at right angles to the crank shaft and is mounted directly in the crankcase. There is no bushing and it’s difficult to fit bushes so as the casing wears the gear doesn’t mesh properly. I decided to stay with the hand pump. Prior to starting the engine for the first time the pump is operated four times and oil runs down the pipe from the pump, through a non return valve and directly into the crankcase. The spring loaded non return valve in the pipe prevents a continuous feed into the crankcase. The revolving flywheels throw the oil up into the cylinder to lubricate the piston and the cams and associated gears located in an adjacent chamber are lubricated by oil mist. The external valve stems are not lubricated but do run in guides. I’m told that as money saving measure valves in earlier Triumph engines didn’t have guides. The stem ran in the barrel/head casting. Riders now give the valve stems a squirt of chain lube at refreshment stops. I couldn’t get the piston in the oil pump to seal using two leather buckets as was the original set up so I made a brass piston with two rubber rings and fitted it to the plunger. This was tested by pumping into a container and the volume of oil delivered was consistent with the volume of the pump cylinder. When riding the bike the idea is to operate the hand pump every ten miles and if you’re worried that there isn’t enough oil in the engine the operator’s manual suggests an extra pump and observe the exhaust. A slight blue trail of smoke behind the bike indicates you’re OK. I bought one of those $15.00 matchbox size speedo odometer things so I would know when its ten miles since the last pump. I was told that initially one gets over concerned about the amount of oil in the engine and the rider pumps too often. Even after being told I did this on my test rides at home and oil ran out of every orifice onto my rather lengthy drive. She was not pleased.

I was able to ride on my drive but as the bike is fairly highly geared I couldn’t get past second gear. The hand change is challenging but I’m sure I’ll get used to it.

I contacted a 1st Time Examiner and made an appointment for an examination. The machine was loaded into my van and we went to the Club rooms on a fine Wednesday morning where Norm Chester carried out the inspection. The bike was passed and the paper work was submitted to the DOT who wouldn’t license it until I produced a receipt and a statutory declaration saying where and from whom I purchased the bike. This is not necessary if you can produce the transfer papers that go with the purchase of a licensed bike. They also wanted a statement from Canberra to the effect that according to their records the bike wasn’t imported after a certain date. Surprisingly DOT in Canberra was able to respond in about nine days. The statement was duly provided and a plate was obtained after the usual hour wait at the licensing centre at Midland. With a plate I was now able to try it on the road.

The road that goes past my place is downhill in both directions which means an uphill climb to get home both ways which is not good for a new engine. There is one shortish flat road off the main one so I decided to use that. I put a temporary basket on the carrier and loaded up some tools and went for a ride. The bike rides quite well. The front forks absorbed the bumps in the road and the generously sprung seat took care of the rear. The front brake, when applied, doesn’t produce any detectable change in the speed of the machine but the rear brake works well. One has to judge these things by the standards of the day the bike was built. The gear lever isn’t all that positive as the gear box is connected to the handle with a turnbuckle. The original connecting rod had a spring arrangement in the rod which apparently makes the gear selection more positive. I’ll have to borrow one as a pattern and make one. Hopefully that will fix the problem.

I think I’m going to like this old bike and now I must get a few k’s on it before the roaring Twenties Ride on the 4th of May. There are a few other jobs to complete. I managed to scratch the tank when the valve lifter control made contact on full lock. The lighting set (which took a couple of years to collect) has been panel beaten and nickel plated along with some more bolts and washers. These items and a more suitable basket have to fitted. It’s been a long time since I started this project and at times it’s been challenging but always interesting. I’ve learnt a lot and had a lot of help and advice from members of our Club. This is part of what this Club is about.

The first object of the Club is “to encourage the ownership, use and preservation of motorcycles and other similar vehicles more than 25 years old” That doesn’t only mean old English bikes it means what it says and that is bikes over 25 years old. You don’t have to be an expert (this is only the second bike I have restored). The way I see it is that you should start with a bike that is not too exotic, one for which parts are readily available eg Matchless, Triumph, AJS or BSA etc. You need some mechanical knowledge, a reasonable tool kit and at times, access to a lathe or someone who can turn bits up for you. Parts sometimes need to be bronze welded, silver soldered or electric welded. There are people around who can do this for you. Why don’t you consider giving it a go?

Riding notes from the Running Instructions issued to the new owner of a Triumph model N.

“To start away with the engine running hold up the clutch lever, which is placed on the left hand side of the handle bar, place the gear lever in low gear position (right back). Very gradually release the clutch lever, at the same time opening the throttle slightly as the engine takes up the load, when the machine will glide smoothly away. If the machine starts with a sudden jerk, the clutch lever has been released too quickly. If the machine jerks forward slightly and the engine stops the throttle has not been opened sufficiently to enable the engine to take up the load. When the machine has attained reasonable momentum, raise the clutch lever and at the same time move the gear lever forward into the second gear position, gently releasing the clutch lever as soon as the gear lever is in the second gear position. Top gear which is right forward is engaged in a similar manner as soon as sufficient road speed has been attained. If after changing up from low to second or second to top the machine goes forward jerkily it is a sure sign that the change of gear has been made to early i.e. before sufficient road speed has been attained. The present day motor cycle is controlled more easily than a car so riders should understand that it is a simple matter to get away quietly and smoothly. The road speed should be controlled by the throttle control with the air lever fully opened. Never allow the engine speed to become so low that the motion of the machine becomes jerky as this put severe strain on the transmission and is bad for the engine. When approaching a hill the best climb will be made if the throttle opening is increased sufficiently early to allow the machine to start the climb at a good speed. Similarly if the hill will not be surmountable in top gear the change down to second gear should be made before the speed is too low for top gear. To stop the machine at the conclusion of a run declutch and close the throttle using the foot brake to make the machine come to rest at the desired stopping place.”

Some notes on starting a cold engine are also of interest.

“When the engine is stiff to turn owing to the oil being cold the engine may be freed as follows: Close air lever, open throttle lever about half way, raise exhaust lever and slowly depress kick start until the inlet valve commences to open. Now release exhaust lever and continue the stoke of kick starter until resistance due to compression is felt. The engine will now have sucked in some very rich mixture which will thin the oil slightly making the engine easier to rotate by means of the kick-starter. Repeat the above once or twice, return levers to the position normal for starting. Press the tickler until petrol pressure is just felt. Fully advance the ignition lever, open the air valve half way, open the throttle slightly, raise the exhaust lever, smartly depress kick-starter at the same time releasing the exhaust lever just before the kick-starter reaches the end on its stroke to allow the exhaust valve to close just before the moment of firing. After starting regulate the speed of the engine with the throttle”.

Elliott Montagu’s 1927 Triumph N model restoration – Part 5

If you are contemplating restoring a machine it’s best to make it as authentic as is reasonable. It will look and ride like it did when the new owner brought it home and proudly showed it to his family and his mates. You won’t run into problems when licensing it and it may be more valuable. The Club defines an authentic machine as follows. The machine must consist of at least four or the original six major components that is engine, gearbox or transmission, frame, forks, petrol tank and wheels. To be classified as original the components must come from a machine of the same make and type, but not necessarily the same year provided that the model concerned was manufactured basically unchanged over a period of years. Faithful reproduction of two of the missing components is acceptable. Over the years tin ware like mudguards and tanks rust, controls and lighting components are removed, bikes get modified and bits get lost. You have to make them, get them made, swap or buy them. Reprinted parts books, pictures and the Club library are good sources for finding out what the parts you have to make or otherwise acquire look like. The handle bars that came with my bike were only fit for scrap. The original bars were 7/8th inch diameter with a bulge to 1inch at the centre where they fit onto the bike. I found a place that sells imperial size tubing. (They make roll cages for competition cars.) I turned up a 1inch sleeve and welded it to the centre of a straight bar. I made it known that I needed someone to bend the bars for me as I reckoned if I did it they wouldn’t be recognisable as handle bars. A talented Club member and a slab of beer got me a “sporting and a touring handle bar.” I chose to fit the touring bar. This Triumph came with either a lever throttle or a straight pulling twist grip control. When the twist grip option was chosen the bike came with a twin lever control to operate the choke and the ignition advance and retard. I had a twin lever control but one of the levers was broken off. It had Triumph stamped on it so it had to be resurrected. I found a 50’s choke control in the Club store and with some modification it fitted into the control body. I turned up a handle that was close in appearance to the existing one and welded it in place. After the component was nickel plated it looked the part. The bike was fitted with a rear stand which lifts the machine high enough to allow the rear wheel to be removed or can be used to support the bike when it’s parked. When not in use it swings up and is secured in a clip on the mudguard. There is a u shaped plate which attaches to each leg of the stand and butts against the frame when the bike is on the stand. A friend of mine had several extra u shaped plates laser cut when he did his restoration on the same bike so I was able to get hold of two and make a stand. The front mudguard stay doubles as a stand for removing the front wheel. I located a stay and purchased it. On inspection it looked sound but it turned out to be paper thin in places. The small drain hole at the bottom was blocked and trapped moisture had caused internal rust. The rusted stand served as a template. (Useless rusted bits can be worth keeping. The Club keeps some rusted parts in the Parts Store. They are very handy if you need to reproduce something for your restoration). I find the best way to reproduce an item like a mudguard stay/stand is to get a solid flat board, place the sample on it and mark the board at various positions around the object. Fit metal pins into the board where it was marked. New tube can then be bent around the pins to reproduce the correct shape. When making sharp bends with tube you may need to fill the tube with sand and seal the open ends before heating and bending. If bending rod, heat the rod to red heat before bending. The feet were removed from the old stand and welded to the new one. I was told that as you pull the bike up onto the rear stand the front wheel may swing to full lock making things difficult and a prop stand would be good although the N type was not fitted with one. I allowed myself this departure from standard in the interest of making life easy. I found an old prop stand in the Club store, made a bracket to attach it to the frame and modified the leg. It works remarkable well. The unusual shape was necessary to allow the rider to get a boot onto it as it retracts under the primary chain case cover. The original twist grip has an outside diameter of 1 and 3/8th inch and the handle bar diameter is 7/8th inch. To keep the feel the same when both hands are on the handle bars, it was necessary to fit a 1 and 3/8th inch diameter sleeve on the left side. A shrink on leather grip will eventually be fitted to both sides of the handle bars. I found that the clutch lever contacted the sleeve before the clutch was fully disengaged. This caused some concern as initially the only fix seemed to be to increase the length of the clutch control lever which wasn’t possible as the end of the lever lined up with a hole in the frame through which the clutch cable passes. Another suggestion was to relocate the lever pivot point. I eventually solved the problem by grinding a bit off the forward end of the lever so that in the rest position the lever dropped down further before it contacted the bracket on which it pivots. This allowed the cable to pull further before the lever contacted the sleeve on the handle bar. A simple fix. All the other cables were made, nipples turned and soldered in place. Not a job I like!

Other items that had to be obtained were a tool box, which was kindly made by a member, a gas lighting set obtained through Club members, brackets to hold the gas generator and headlight, a basket for the carrier (I bought at a market), a license plate holder for the back mudguard and other small items. I had no idea how to make the license plate holder. A friend told me how. Cut out the shape you want in cardboard. Trace around it on a strong (jarrah?) piece of wood say 3/8th inch thick. Cut the wood to shape. Get a piece of suitable thickness plate and bolt it to the wood. Cut the plate around the shape of the wood (I borrowed my neighbour’s nibbler) leaving enough metal to bend over. To ensure rigidity, with a suitable hammer tap the plate over the edge of the wood. Cut vees where necessary at the corners. The vees can be welded up later.

So most of the work is done. It is now time to set the timing, put some oil and fuel in it, see if the thing starts, see how much oil leaks out and from where and how to stop it.

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Elliott Montagu’s 1927 Triumph N model restoration – Part 4

After months of trying to source an original clutch it became obvious that there just wasn’t one available. A friend of mine in the Club said no worries we will make one. (I’m not naming people because I might forget someone who helped me). I had one component of the clutch and that was the splined ‘clutch driving member’ that fits the driven shaft of the gearbox. The clutch driving member also has a large diameter track to take the bearing on which the basket runs. I was fortunate to have this component as manufacturing it would entail machining splines and case hardening the bearing track. The basket that holds the clutch friction discs and clutch plates was spun. A flat steel disc of suitable thickness is retained in a lathe and as it turns the operator applies a tool with a long handle and bends the metal as it turns until the metal is shaped as in the picture. Slots are then cut to take the friction plate lugs. The first attempt using the spun basket didn’t work too well. I welded a band around the basket to stop it opening up as pressure was applied during the operation of the clutch but the addition of this band caused some distortion and balance problems. The fix was to machine a basket out of a piece of large diameter aluminium bar. Another friend machined the basket and milled the slots to take the clutch plates. New AJS parts are used for the plates, the clutch springs are modern Triumph and rollers are used in the bearing.

The clutch is driven from the engine via a chain wheel attached to the basket. The number of teeth that can be accommodated on the clutch chain wheel depends, to some degree, on the overall diameter of the clutch which itself is governed by the diameter of the clutch plates. The clutch and chain wheel and chain have to fit into the primary chain cover which is designed to accommodate fore and aft movement of the gearbox to allow tensioning of the primary chain. The unit had to be made to fit or else the primary chain case cover would need to be modified. My main consideration, however, was to keep the final ratio the same as the original bike. The ratio is all about how many times the engine crank shaft turns over for one revolution of the back wheel. If the ratio is considerably different from the factory spec. the engine will either be revving fast or labouring in a particular gear for a given road speed. Apart from the design of the gearbox, the ratio depends on the number of teeth on the engine, clutch, gearbox and rear wheel sprockets. In my case the gearbox and rear wheel sprocket were factory original and the clutch sprocket was fixed by the dimensions of the homemade clutch so the only sprocket I could change to achieve the original ratio was the engine sprocket. The final ratio is calculated by dividing the product of the number of clutch sprocket teeth and rear wheel sprocket teeth by the product the number of engine sprocket teeth and the number of gearbox sprocket teeth.

The original ratio for the bike in top gear was 5.06:1. That is the crankshaft turns 5.06 times for one turn of the rear wheel in top gear. I had the clutch with 36 teeth and the rear sprocket with 38 teeth. Multiplying these together we get 1368. The gearbox sprocket had 15 teeth so I chose 18 teeth for the engine sprocket. Multiplied together, 15 and 18 equals 270. Divide 1368 by 270 and we get 5.06 which is the ratio required. I bought a blank sprocket with 18 teeth, machined the original engine 15 tooth sprocket off the boss and welded the 18 tooth blank in place. When everything was assembled it all fitted OK in the primary chain case cover. The slotted holes in the frame that take the gearbox retaining bolts were long enough to allow proper adjustment of the primary chain which meant that the rear wheel chain adjustment available was still OK. It all looks good but the question yet to be answered is does it work?

After the clutch was finished my attention turned to the handle bar fittings and cables. I emailed UK seeking a period clutch and brake handle. I should have said that I want a period clutch handle and brake handle because the recipient read it as I wanted a clutch and a period brake handle. He could supply both. After making one I was now offered the genuine article. I had to buy it of course and it came in excellent condition with new friction plates. To fit it to the bike I would have to change the engine sprocket again so I’ll see how the home made one goes. Handle bars, fittings and control cables can be a bit fiddly but that’s story for another day.

Elliott Montagu’s 1927 Triumph N model restoration – Part 3

Surprisingly the carby wasn’t difficult to obtain and it came from the UK in excellent condition with inner and outer cables and complete with a float and needle.

The gearbox casing I had was compatible with the earlier scissor type clutch but my machine was fitted with the pushrod type which requires lugs on the casing. I took some measurements off another bike. Made some lugs and had them welded in place. My attention then turned to getting something to put in the gearbox. After twelve months I still hadn’t been able to source the innards for the gearbox. My luck changed at the Bunbury IHC Rally. One day’s riding ended at Boyanup and while waiting at the finish line I got talking to an IHC member. After telling him about my search for gearbox bits he said he thought he had the right gearbox in his shed which was about 300 meters from the finish line. We went over to the shed where he ratted around in his collection of bits and pieces and produced a gear box full of gears. It was exactly what I needed. A price was negotiated and he brought it to Perth when he came up for the Swap Meet. The gears were in good condition. I fitted new bearings, turned up bushes and made leather seals.

I also needed the part which attaches to the lugs we had welded to the gearbox. It has the rather grand name of a ‘gearbox clutch control buttress’. (I still didn’t have a clutch for it to control but more about that later). Eight months of trying to locate one of these buttress things proved fruitless. Once again a Club member came to the rescue and offered to cast one for me. I borrowed a buttress off a mate’s bike and we used it for a pattern. Each side of the part to be made was pressed into special sand contained in two halves of a box. Before the two halves were joined small channels were gouged in the sand to allow the molten metal to reach all corners of the impression. The furnace was fired up, metal scraps and off cuts dropped into the crucible. When the metal was molten it was carefully poured into the mould and on the second attempt we had a gearbox clutch control buttress. In the Club parts store I found a control rod that was so close to the original that with some minor modification it did the job. I turned up a stainless steel pin to secure the control rod to the buttress and another problem had been solved. Solving the clutch problem didn’t prove to be so easy.

Elliott Montagu’s 1927 Triumph N model restoration – Part 2

1927 Triumph N restoration – continued

To continue from last month, the frame and forks needed a little work but were generally OK. The wheel bearings were replaced, the brake drums skimmed, linings renewed, new axles made and the wheels respoked with stainless steel spokes. It was a physiological lift to see something that resembled a motor cycle standing in the shed. I needed a set of flywheels but in the meantime the cylinder was rebored and a piston obtained. Fortunately the engine came with the cams. Valves were manufactured from new car valves, guides were turned up and springs obtained from the UK, main and big end bearings were bought. After about twelve months I sourced a set of fly wheels but on dismantling them I found they weren’t much good. The lack of fly wheels was becoming a major problem but was fixed when a Club member who had heard I needed flywheels brought a set along to a Club meeting and kindly donated them to the cause. I had two conrods both of which were checked for straightness and twist. The lathe bed does as a flat surface for this. The flywheels were assembled using the best conrod and the assembly trued using a dial guage. Engine retaining bolts were made and bolt heads and nuts were turned to replicate the original article. The engine was assembled and I then turned my attention to getting something to put inside the empty gear box that came with the bike bits. I was also short of a carby.

Parts pickup at Bunbury

These pics were taken when we picked up the last big purchase of parts in Bunbury. It shows some of the behind the scenes activity by members for the Club. Greg Boothey supplied the truck.
pics supplied by Elliott

Elliott Montagu’s 1927 Triumph N model restoration – Part 1

In October 2008 I bought a frame, wheels, tank and some engine bits that were parts of one of six 1927 Triumph N models imported into WA. As you can see from the photos I had a lot of work ahead of me if I was going to make a roadworthy Club bike out of what I had. It’s now getting close to completion and my target is the Roaring Twenties Rally next year. There are many Club members who steered me in the right direction for obtaining parts and general info on the machine. Some bits took over a year to find. Peter Cornelius, the Vintage M/C of United Kingdom’s early Triumph expert was also very helpful. Peter who lives in NZ visited this club a couple of years ago and gave a talk on early Triumphs.Over the next months I will put some photos and words in the e-Chatter in the hope that it might encourage some of our newer members to give it a go. There are less ambitious projects around and plenty of info and help available.