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!