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Jonghi 350 sidevalve, new life!!!

47K views 305 replies 31 participants last post by  CookieMonster 
#1 ·
Hi all,

Should really start at the beginning... in 1976 I read a 1959 article about an Italian engineer who lived most of his life in France. He was Guiseppe Remondini.

He had founded the Jonghi make in France with the financial help of a dubious Argentinian arms dealer called Tito Rodolfo Jonghi (I also found one of his other aliases, Rodolfo Von Chegger...)

The 1959 article mentionned the village he was living in, so, I, full of hope if not money, jumped in a train and went there. The station was about 5 miles away from the village, so I walked, it was in the countryside!!!

Found the house, found from a neighbour that he died about 6 months after the article... Then another soul (I was fearless and just knocked on doors...) told me his son Arigo wasn't living too far away... Where? The village where the station was!!! 5 miles again but the other way... By luck, Arigo was in and he went in the roof space and came back with a cardboard box full of old 5 x 8 photos of wonderful bikes.

He lent me about 100 and that was my first article for our French Vintage Bike Club and the start of a lifelong passion for Jonghi and its strange history.

In the stash of photos were these two of their 350cc side valve that took the 24 hours world record at 116km/h, about 72mph in March 1933:





One could clearly read on the originals the engine serial, TT 2, stamped on the timing cover.

In order to do that article, I visited friends who had parts or stories and at one, I saw the complete timing cover stamped TT 2... Pennyless as usual, I let it lay for the time being...

Patrick
 
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#182 ·
I never thought a fuel tap could be so interesting, that’s a really nifty little assembly Patrick! I don’t know much about the regs and it’s probably glaringly obvious to others - I take it when you fall off and part ways with the bike, the lanyard pulls away and then the spring releases to shut off the fuel at the same time as killing the magneto with the switch?
 
#185 · (Edited)
Hi...

Never sewed in me life, so a 1st...

Started the tank leather pad.





After a few trys, this is the outcome:



But I used all the strong thread I had, so waiting for some more so I can start on the 4 straps....

Found a Ferodo lining box:



Miracle: nearly the same diameter...



Glue...



I'll rivet and trim them later once super dry......



So long, Patrick
 
#188 ·
Good sewing Patrick, wouldn't have been done on a machine back then anyway right?

I found an old boy in Hoylake who works on train brakes and will fit any grade of brake lining you like and grind to match the drum - he uses adhesive you bake on in an oven, or will rivet. He did two sets of shoes for me for £60. I'm trying the woven stuff with the copper wires:



Are you going to match them up with sandpaper?
 
#192 ·
Hi,

Good day today, collected all my machined bits from B&E.

Keith, workshop manager:



Levers for the petrol tank caps:





My friend Frederic in France dis these special nuts for me:



Cylinder deck milled and square to crank:



I did the manifold, B&E did the thread and castlenated nut:



Inlet track bored to 28mm, plus new M33 x 1.00 thread:







General view...





So long...

Patrick
 
#195 ·
Thank you for saving a piece of history. It looks like an awesome engine. I'm sure the rest of the machine was built with the same care.
 
#196 · (Edited)
Hi,

No plan at this stage for repairing the broken fins!!!

B&E also did a few alloy weld in there.

One of the TJ 4 problems is the sliding 2nd gear in the crash gear box. Not only it slams into his brother every time one changes gear, but it also is not help by the wet clutch which makes it difficult to obtain a clean separation of the driving and driven plates. So I decided to use ATF in the gear box and primary spaces, this is a solution most used in 70's Sportster,

The engine oil in the Jonghi is circulated via windows and they have been welded shut.





B&E also repaired the broken clutch cable anchor:





Patrick
 
#199 ·
Hi Jaws,

Engine runs backwards (geared primary). Gear oil pump oils the crankpin and the cams via drilled holes in case and timing shaft. Then oil get sprayed out in the crankcase.

There's a window between crank and gearbox, so gearbox gets filled with engine oil as cranks rotates.

When a certain oil level is reached in the gearbox, it drains into the primary and lube the clutch and transmission gears. Same again, when level is too high in the primary case, the oil drains back into the crankcase and cools in the sump.

I blanked all these windows so I can use engine oil in the crankcase and ATF in the gear box and primary.

Patrick
 
#201 ·
Ah ha. Ok that makes sence. I never liked the idea of mixing gear cases with the same fluid... seemed an easy way to add more contaminates to an already delicate situation, tyring to keep the engine oil clean.
 
#203 ·
Hi,

Other stuff done this weekend: mods to the oiling system.

There's a hole in the primary cavity that transfer lubricant back to the sump:



Blocked it with a screw.

I transfered that level to the primary cover for a new level plug::



No breathers left for gearbox and clutch cavities after all the welding, so install a new fitting on top of the box for a breather pipe:



Since the bottom of the box is much higher than the botton of the clutch, design of a transfer system between them, using centrifugal and gravity forces: litthe dam with hole behind to collect ATF from clutch cavity and to transfer it to the box:









Also drilled big breather hole in between both cavities:



So the box will fill with ATF from the clutch, so new hole down to limit level in box and diminish ATF volume:



In the timing cover, there were just 2 little holes to drain it into the sump, same, increased hole size to speed up drainage.



So long...

Patrick
 
#204 · (Edited)
Hi...

Considering the race cams and the rpm, 6000, I thought I'd better find stronger valve springs!!!

These are internal Sportster ones, with their cups moded to suit.

With valve lift, it leaves 2mm before coil bind and before the lower cup hit the valve guide, so all good and a lot more pressure..

On the left the mod, on the right the std set up:





Patrick
 
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