Pieces

According to an expert, the frame is from a Monark 1929 350sv. 

As it happens I have a sutable engine (should have been a Blackburn), a JAP 350sv from 1929, featured in another post in this blog. I also have got a 1929-ish Albion 3 speed gearbox (should have been a Burman) that also fits the frame.

Featured in the picture is a Husqvarna 250 1929 oil tank. Got it cheap, did not know why, not before I started looking for an oil cap.  Had to buy a new replica oil cap and thar was not that cheap.

Rear wheel has now got a NOS Trelleborg Trial tire.

The seat is a rear seat from an unknown bike. But in wery good condition and from the same manufacturer that made seats for Monark, Husqvarna, Rex an other Swedish motorcycles at the time.

Slow but steady progress, not.

Take two

The hunt for parts for the Matchless girder fork has NOT been successful. Now I have found another lost cause instead.

Monark circa 1929 about 250 - 350cc. As rusty as the Douglas frame, if not worse.

There are some parts missing from the front forks (fastener for the handle bar) but nothing crucial that can not be replaced or made.

I did not get the correct petrol tank, that might be a problem. Now I am waiting for the Husqvarna oil tank I bought. Almost the same model as the ones used for the old Monarks. Hope it fits.

Girder Parts

For some time I have been planning for making the missing parts for the Girder Fork. First information I got from a "specialist" was that my fork is home made by some local black smith.

This I have believed for years but now I found an identical on some 1920:s Matchless motorcycles.

Searching the internet I also found a Parts List front fork.

I think I will have to make my own version of the upper yoke and linkage. With or without dampening.

Scrap

One Man's Junk is Another Man's Treasure.

Last weekend I managed to come by a box of parts that I hope can be used for the engine rebuild.

The camshaft and lifters are not in mint condition bout should be usable. At least in a much better condition than the ones I've got.

Framed

The other day I found a frame that, with some modifications, maybe could be used for the 350cc.

A rusty old Douglas EW 350cc frame and a HVA wheel with clincher rim.

Since it was made for a boxer engine there is no belly, the lover frame tube will have to be replaced with a new one. The clearence is 33cm but the JAP engine need at least 44cm to fit

Made a rust solvent from Acetone and ATF oil. Hopefully the steering stem is still usable. 

The handle bar is no longer seized but the steering stem is...

Magneto

In my quest for sparks I have started piling up useful things. Junk might be a better word.

Todays visit to a swapmeet got me a SEM magneto and a brand new 18mm Lodge spark plug that might be useful for the 350cc engine.

Yesterdays swapmeet got me a brand new ignition coil, that might fit the Wico magneto that came with the 600cc engine.

The used coil at the bottom..

At last weeks swapmeet I got me a pile of used and new spark plugs for both engines.

Forks

Even though the update frequecy on this blog is close to infinity, the project is not completely dead. I am constantly looking for possible parts for the project. Today I bought a girder fork, or at least half of it with the intention of making the missing parts myself.

Sorry to say I do not know from what bicycle, moped or motorcycle it came. Neither did the seller. Would have been easier if I knew how the parts should look like.

If the knowledge is out there, please let me know the make / brand.

Exhaust nut test

Made a new sample nut from high grade aluminium. My intention is to make a final version as soon as I get new, suitable insers for making inner thread (managed to damage the only one I got). Otherwise I will have to use this one and maybe make a somewhat larger dimension hole for the exhaust tube.

Exhaust Nut

Had to cut into the nut to get it loose. That does not matter since it is wery corroded and has to be replaced anyway. Thread is 20 TPI and I measured the outer diameter to 44.3 mm which I presume is  1¾ inch (44.45mm).

The new nut will be made from brass or brose. it will also be made for use with a hook wrench insted of a regular spanner.

At the same time I dismantled the valve gudes and destroyed my valve guide tool that was special made for another engine ..

Small step

Made some progress with the valves. Unfortunately I have a house and a garden and it's spring time and ...

Anyway, managed to mill the holes in the valve stems and cut them to the appropriate lengt. Since I do not have any valve grinding machine I will have to make a jig to grind the end of the valve stems. Hopefully this weekend (as long as the weather is rainy I can't do any outdoor painting).

End mills

Finally got the end mills I ordered all the way from China. Sold as Solid Carbide HRC60 and as such they should have no problem milling stainless steel stems, or...

Valves

According to an old James Catalogue, the valve dimensions are as follows.

According to my measurements the valves are somewhat longer.

Anyway I'm not patient enough to wait and see if any JAP valves will pup up so I scanned through some valve makers catalogues and found out that Manley GEN II exhaust valves are pretty close.

Found a set of eight valves for sale on eBay. These were custom made and the valve head was close enough to fit without modifications.

Valve head = 1.6" & Valve stem 7mm

Of course they will have to be shortened and modified with slotted stem ends.

The main concern is if they are too heavy compared to the original ones.

In case they can't be used I'll buy some used NASCAR titanium valves and try to modify them instead ...

Oil Pump

It seems I can not get hold of a period correct oil pump.
When bidding on eBay there is always someone that has more money.

I'll use a Jawa oil pump, if possible, until I find a suitable Pilgrim or a Best & Lloyd or...

Valves

Still have not found any valves. An option is to adapt valves from a newer/modern engine.

Using valves with cotters would mean I have to find suitable collars too.

Intake and exhaust nuts, prologue

Rusted as if they were welded to the cylinder, but at first I had wery low expectations regarding the Spark Plug and Valve Cap too.

Maybe this will solve it self after the cooling fins have been welded. Either by the heat from the welding or when the cylinder cracks when cooling after welding.

Intake

Tried with an adjustable spanner but did not dare, in fear of ruining the nut. After more soaking in citric acid it looks like the thread is left handed.

Anyway, the thead has been soaking in penetrating oil while I have been loking for a ring spanner with the appropriate dimension. Measured with a cheap vernier caliper it measures about 32.5mm. Have not been able to find such a spanner. The closest I have found is BSF 7/8 or BSW 3/4. That would be 1.300“ or 33.02mm which it could have been before all the corrosion started.

I think I'll try a 32mm ring spanner and with some luck that will fit. Buying a imperial size spanner is the last option. I might even grind / open up a metric open end spanner before that.


Exhaust

This one is a real challange. Maybe I'll try to cut the nut to get it off.  Both because the required spanner and the condition it is in.

Think I might have to make a new nut anyway... maybe from broze or brass?

Valve Cap

Made out of aluminium, but just got one out of two.

 

I'll try to manufacture a pair in my lathe even if the hex head is not that easy to make in a lathe (have not got any milling machine).

Wonder what thread it is? The pitch is 1,5mm and that would correspond to 17TPI and that is no standard thread as far as I know. Will make the hex head 38mm which is 1 1/2"

Cooling fins

Made from sheet metal since I could not find any large enoug cast iron cylinder to scavange.

The tricky part will be welding them to the cylinder.

Cylinder

After three days in a bucket with a mix of water and citric acid followed by a light brushing with a wire brush.

Now it's time for new cooling fins.

Notice the mark on the intake tube where the level of the ciric acid water has created a visible "border" in the rust and dirt. I still do not dare to try to open the intake nut. I also think it's treaded the wrong way, so to say.

Small Timing Gear Puller

To remove the small timing gear on the crankshaft I had to make a special  puller from a steering ball joint puller. Colonel Johan August Sandels is overseeing the procedure.

Engine identification

The engine was sold as a 250cc and the engine numbers might suggest that too. At least if one thinks /B stands for the cc.

Nothing seemed to add up and I could not figure out the meaning of the numbers and letters. When I measured the bore and stroke I came upp with approx 70x89. That would be 350cc I my book.

Trying to decode the serial number by the info on http://www.railtruck.org/jap_dating.htm I came up with the following:
I/S     I=350cc side valve, 70x90mm bore and stroke, S=1929
75163/B      75163=Serial number, B=Modified gear cover and exhaust valve lifter
H      H=Roller bearing pulley spindle
M     M=Crankcase without oil box.

Of the above everything seems OK until the letter M. At least there is something I would call an oil box.

But of cause the last paragraph on that page says "... this list is by no means infallible."