Panther 1935 Model 50. 3. The Search for Parts

Naturally with a machine in this condition and of this age there are a lot of parts to find and usually they do not readily come to light. I have been playing with Panthers for almost 40 years and in my time have owned many of the different models from a 1921 500 to a 1962 Panther Princess Scooter so I have collected a pile of odds and ends. These are not catalogued or organised so I have had to search through the junk to see what I had that could be of use on this project.

Since finding replacement Model 50 flywheels seemed unlikely, I decided to rebuild the engine as a 600cc. I had owned a 1933 M100 so there was a good chance I still had some suitable bits laying around. I had good dig in my jumble of parts and this produced an early barrel of standard size in usable condition. These barrels have a small upstanding top lip, unlike the later ones which have a large flat for the copper gasket. I also found a standard slipper piston, some suitable rings, a cylinder head which would fit the rocker box supplied with the bike and a suitable conrod. My stock of Model 100 taper fit flywheels appeared to be a pile of mixed pairs with balance holes all over the place. I decided to use the pair I took from the engine of the Wreck, the subject of a former blog, knowing that they had run together. These were very rusty having lain in water for 25 years but being made of cast iron the rust is only on the surface so they should clean up well and are uncracked. 

Flywheels from the Wreck before cleaning.

Other parts came to light; the large top engine hanger, a rear brake lever. the dynamo drive sprocket rings for the magneto drive, a dynamo sprocket, valves, springs and the collet fittings, suitable push rod ends (no pushrods), some worn tappets, the tappet block and pushrod tube, a carburetter, a pair of crankshaft roller bearings and a new big end missing its outer race, steering head races, an eight inch headlight and all the parts for a clutch. All of this stuff needs work naturally but other parts may surface in the fullness of time.

Correct head

M 100 Barrel and Slipper Piston

Original ring set.

Push rod tube, carb, brake lever, U-bolt saddles,
top engine mounting.

Dynamo spacer, (cast by Sherb), conrod, cams, push rod ends.

Clutch parts

8 inch headlight

I then turned to the POC Spares Department, that excellent service available to all Panther Owners Club members. Anticipating a problem with stretched tapers in the old flywheels I bought a big end with slightly oversize tapers. Spares Secretary Ian Fox turned up with the short engine top hanger; it is different to later ones as it fits on the U-bolt and not on a pair of bolts at wider centres on the rocker box. He also produced a rear stand, a pair of refurbished cam followers (on exchange) and the chain cover for the dynamo drive. Rex dropped by with a front mudguard with the correct long trappings that clear the Webb forks.

Refurbed cam followers, small top engine mounting, big end,
dynamo chain cover, dynamo mounting strap.

Rear Stand.

 On Ebay I found a pair of remanufactured top fork links to replace the home made ones and a set of hardened washers for the spindles. A visit to the local Metal Supermarket produced a length of half inch diameter EN24 bar to make a set of fork spindles.

Head races, new fork links and washers

As I was in the throws of making a chainguard for the Model 70 I made a second one for this project, then I measured up the battery support on my 1936 M100 and made one of those too.

New Chainguard

Battery support

A photo appeared on the Panther Facebook posted by Markus Orth of an aftermarket speedo drive running from a large gear on the front wheel. I had the large gear, and low and behold, I have had the rest of the drive in a cupboard for years; at last a use for it.

Markus Orth's speedo drive

Speedo drive gearbox and Smiths MA Speedo

This collection of parts took a serious turn when I posted photos of this project on the Panther Facebook page along with an appeal for parts, particularly a gearbox. This should be a  Burman BAPH with front and bottom mountings. I have two early CP boxes which have top and bottom mounts and I toyed with the idea of removing the top one and bolting a mount to the front. Also I thought of fabricating a battery tray to include a top mount. However FB produced a response from Shaun Omaonaigh in  Australia who offered me most of a box at a very reasonable price although that was doubled by the cost of shipping halfway round the world.. This was without the kickstart case cover and the contents of the kickstart case  Shaun also had a BA body shell with the correct mountings.  I discussed with Fred Baggs the possibility of using parts from the CP box but Fred confirmed that there was little chance of the parts fitting correctly. 

BAPH gearbox as offered

BAPH shell offered

I further bent Fred's ear asking if later BA parts, of which I have a stock, would fit the early shell. The answer was again in the negative.

I gratefully accepted Shaun's offer of the part box and contents and tracked its slow progress as it moved to Perth airport, thence to Coventry and finally here. Foxy alerted me to a kickstart cover on Ebay and I snapped that up. This solved one problem as I found that the kickstart ratchet from the CP box would fit and the selector parts from later BA boxes are the same and I had plenty of those.

Kickstart case cover from Ebay.

Finally Petsch in Germany sent me a Miller dynamo.

Miller dynamo.

I am sure there are many other minor parts to be found but I have now collected a fair proportion of the bits required to assemble another Panther. So let battle commence, onward and upward!

My thanks to Fred Baggs, Ian Fox, Shaun Omaonaigh, Rex Norton and Ralf Petscheleit.

Panther 1935 Model 50. 2. The Mechanical Bits.

 I shall start with the gearbox as that is the easiest to deal with. I don't have one!

The Engine.

The Engine before removal from the frame.

Noticeable in the photos is the absence of any valve gear and the fact that the head is pre 1933. The valve head sticking out is purely ornamental! 

On the bench I lifted off the head, it wan't bolted down, to find the complete absence of a piston. The cylinder is 84mm in diameter plus 60 thou.  The piston should be a two ring Hepolite ref. 3121 which needs a conrod longer than that used with a three-ring piston.

500 cc piston.

With the cylinder off I removed the timing cover to find a full set of timing gears but no half-compression bits. The crankshaft pinion is stamped 14.5 PA although some of the digits are reversed.

Crankshaft pinion stamped 14.5 PA

Timing gears and oil pump.

The magneto drive bush is totally worn out and the sprocket for the mag chain is wrong.

Top, damaged hub and worn bush, Btm left, sprocket as found,
right, as it should be.

 There are no pushrods, tappets, tappet block or pushrod tube. No valves, springs, collets etc.

I separated the cases and removed the main bearings, a pair of LJ11/8 inch R&M ballraces. Splitting the flywheels revealed a knackered big end with the race turning freely in the conrod eye, so loose indeed that it fell out. The rod is a long one and the small end is missing. Because of wear in the big end eye the rod is scrap. 

Late rod, top, Rod as found Btm.

Also scrap is one flywheel which is cracked between the mainshaft taper and the big end taper. As this is a 500cc engine the flywheels have a throw of 90mm rather than the 100mm of the Model 100.

Crack arrowed.

The crank cases are not too bad although one main bearing is loose in the case, it just fell out. The lug on top of the timing chest for attaching the dynamo chain cover has been cut off and the two studs which fix the magneto down are stripped out. 

Top, lug cut off, lower, mag stud holes (repaired)

The timing cover has a corner broken away and a plumbing fitting has been used to plug the oil filler hole.

Broken timing cover.

The rocker box that came with this bike is the correct one, in fact I had sold it to the former owner some years ago. However it does not fit the head supplied with this engine which is pre 1933.

Rocker box.

All in all it is bit of a mess and there is no way I can rebuild it as a 500. I have several new pistons of the correct type but they are all plus 40 thou and I have a replacement long conrod. However I do not have a pair of usable Model 50 flywheels, nor a plus 40 barrel.

Along with not having a gearbox I did not receive any clutch parts. I did though get a primary chaincase, albeit one with the large hole for the boss on the finned sump engine. It does not fit the round sump crankcase. 

Chain case, post 1935 type

I need to explore my stock of bits and see what parts I have, then look at the options. Or maybe just throw it away!

Panther 1935 Model 50. 1. What Have I done?

In late March 2021 I was busy rebuilding a 1947 Panther Model 70 when I was offered a 1934 M100 for restoration. I just had to accept, perhaps foolishly. Money changed hands! Upon collection there appeared to be less there than I expected but I went ahead anyway and duly took the spoils back home.

Upon arrival

Fuel tank

Primary chaincase

As the photos show it was really the bones of a bike, but what bike? The engine Commission Number is F5046. Referring to Barry Jones' excellent P&M history F denotes a Model 50 500cc, and the 5 denotes 1935, the 46th heavyweight engine commissioned that year. The engine build number on the magneto platform is A50 2627. Referring again to Barry's book, the engine builder's code A "appears to have never been allocated", yet here it is! So the builder remains a mystery. Certainly 50 refers to a Model 50 500cc, the 2627 shows this engine to be the 2627th heavyweight engine built since September 1931.

The frame number is badly worn but appears to be 10620. This cannot be related to a date as the Panther Owners Club Registrar has no factory records from August 1934 to end of 1936, I have a log book for a 1934 Panther dated 30th May 1934 for frame number 9727. Frame numbers were consecutive for all models except Panthettes from 1924 and production seems to have averaged around 80 per month during that period suggesting eleven months from May 1934, giving April 1935. That is approximate and conjectural. Naturally there are no documents with the bike.

It has been suggested the bike is 1934 as it has the round -sump engine; The Model 100 changed to a finned sump for 1935 models but it appears that the Model 50 retained the round sump until it was discontinued in late 1935.

P&M Catalogue 1935, M100 finned sump,
M60 and M50, round sump.

So what have I actually got? What I haven't got would make a longer list! I have most of a frame, Webb forks (possibly not Panther ones), an engine, a pair of wheels (though the front one looks a bit odd), a primary chaincase (later type), handlebars and controls, a rear lifting loop, fuel tank and a pair of exhaust pipes (new). It also came with a gearbox from a Model 75 and a post-war rigid rear mudguard, (a new pattern one).

I don't have a gear box, a magneto  a dynamo, the battery bracket, a rear stand, engine hangers, footrests, toolboxes, saddle, headlamp, front mudguard, speedo, rear lamp, number plate, rear brake lever, silencers, cables or wiring. I began the long process of assembling the relevant missing parts by digging around in my pile of boxes of Panther bits. I found I had a 30s cylinder head, a suitable rear brake lever, the long engine top hanger, a Chronometric speedo, a saddle frame and an 8 inch headlamp. So I probably paid too much but where do you find another one? (Actually I once bought a pre-war Panther frame with the double down tubes at Netley Marsh Autojumble for £25; those were the days!)

More details before dismantling.

Although busy on the Model 70 I decided to tear this bike apart and reduce it to its component parts. The engine dropped straight out as it was only  held by the three bolts to the engine plates. The frame soon came apart and although many of the bolts looked rusty it all came apart quite easily. I understand the bike had been brought back from Denmark some years ago; the sidecar fitting on the right hand side of the rear frame suggests use on the Continent. The tyres are completely bald, I'm not sure how anyone could have ridden on them in that state although the back one did have some air in it. I took those off and dumped them at the bottom of the garden for now. (How do you get rid of old tyres as the pile is growing?)

I examined the pile of bits in turn, leaving the engine for another day. I do have a 1936 M100 that is original and complete so I have something to compare against.

Main Frame. this looks ok and appears to be unbent. There are no bearing races in the headstock and the frame number is almost illegible.

Chain stays. These unbolt from the main frame. They are bent slightly at the front end and the rear part that carries the rear stand has been cut off on both sides beyond the axle slot. The right hand stay is fitted with a sidecar ball confirming its use on the Continent.

Engine plate. These are both bent slightly at the back end.

.

Forks. These look like Webb heavyweight type but do not appear to be Panther, they do not have the large lugs that support the headlight on a Panther nor the tapped holes in the top yoke.  Comparing the girder to that on my 1937 M100 shows that the distance between the two spindles is greater on this fork which will necessitate some spacers on the headstock stem.  The brake anchor on the girder appears to be on the wrong side.. There is a friction damper on each side but the bores on this and on the girder and top yoke appear to be unworn. The top links look to be home made and the spindles are all of mild steel with coarse threads and no hardened washers or means of adjustment. There is no steering damper. and there is only one head race present and no balls. However the fork is not bent and appears eminently usable.

The petrol tank is the correct type which takes the deeply recessed cushion type knee grips. These are unobtainable. The tank is bare, no taps or cap but still has the painted panel which will provide a good reference. It is rusty internally and needs to be checked for leaks.

The handlebars have all the control levers present but everything is quite rusty.

The wheels are rusty but complete. The rear rim is wider than that on the front and the front wheel is fitted with a large gear for a speedo drive.

Front wheel

Speedo drive gear on front wheel.

Rear wheel brake side.

Rear wheel sprocket.

That's the sum of the Cycle Parts, the mechanics can wait for another day. If anyone has any comments, particularly on the forks I'd be glad to read them.

So far, so good. My thanks to Rollo Turner (I think!)