Author Topic: New Vintage Project, 250cc M-VG, Reconstruction of a 1933 French Jonghi 350  (Read 90729 times)

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Offline thefrenchowl

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More pics then, Wobblywalrus!!!

Crank and its 2 main ball bearings (there's also a 3rd one between the drive gear and the outside flywheel, located inside the primary cast alloy cover)



#114 again...



The small TJ stamp found on all the machined parts:



Found opposite the above one, an even smaller stamp, was lucky here on the oil pump drive gear, it is usually totally unlegible...



Bronze bodied oil pump and ancillaries:



I then tried to pull out the clutch holding plate, no luck... Rather than do sommat silly, went and done the small alloy plate to bring the magneto to the right hight, about 1/8" thick:







Bye for now, have a good Easter break...

Patrick

« Last Edit: March 30, 2018, 05:27:48 PM by thefrenchowl »
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Offline thefrenchowl

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A day more was enough to come up with the goods to get the final bits of the gearbox out...



Four ball bearings in there, with three being obsolete, made out of unobtainum...

Clutch bell one:



Two similar ones, big diameter and dead skinny, that support the secontary gear assembly, all made in one piece:



And as usual with "crash" gearboxes, 2nd gears are well worn out. I will visit a local gear manufacturere to see what can we do to renew them...





See you around, back to work tomorrow... : O (

Patrick
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Offline thefrenchowl

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Hi all,

Small packet arrived from France today from Claude Caucal who passed to me the TT 2 racing parts...

Contained the slide spring and the air intake for the carburettor... Many thanks!!!





Bit by bit, the puzzle gets there!!!

Patrick
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Offline thefrenchowl

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Hi, boring stuff done recently, cleaning bits mostly...  :-(

Following problems 2 weeks ago with clutch castlenated nut, I redone the spanner to make it tighter and foolproof...







Also done a wooden jig this weekend to evaluate the rebrazing of the twin floats at the right angle for my horizontal carburettor:







Will transfer all this to a proper steel jig next weekend...

If one of you has good tips to silver braze these brass bits, I'm all ears!!!

See you all soon,

Patrick
« Last Edit: April 24, 2018, 11:45:37 AM by thefrenchowl »
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Offline wobblywalrus

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Reply 45 shows the small stamp on the oil pump gear.  Is that a crack at the root of one of those teeth?  That looks like a great build.

Offline thefrenchowl

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Hi,

Made a proper steel jig to braze the float chambers...



Brazed half yesterday...



Was not too sure, looking at the brazing, so I switch off and did all the bits for the carb air correction channel:





Finish the brazing today:



I only have a micro miller in the garage, too small for the spot facing, so another jig in the lathe... Not too successful, not rigid enough and too much overhang hence vibrations... I'll drop the floats at my fav machinist in the week...



In the mean time, a good filing seance to clean all that extra silver braze...





So long, Patrick
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Offline Old Scrambler

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Nice work :-) :-) :-)
2011 AMA Record - 250cc M-PG TRIUMPH Tiger Cub - 82.5 mph
2013 AMA Record - 250cc MPS-PG TRIUMPH Tiger Cub - 88.7 mph
2018 AMA Record - 750cc M-CG HONDA CB750 sohc - 136.6 mph
2018 AMA Record - 750cc MPS-CG HONDA CB750 sohc - 143.005 mph
2018 AMA Record - 750cc M-CF HONDA CB750 sohc - 139.85 mph
2018 AMA Record - 750cc MPS-CF HONDA CB750 sohc - 144.2025 mph

Chassis Builder / Tuner: Dave Murre

Offline thefrenchowl

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Thanks, Old Scrambler...

My friend did the spot facing this week, all good and tested for no leaks...





Doin' the float's ticklers at the moment...

See you, Patrick
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Offline thefrenchowl

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All the Jonghi engines have a pairing number... This one is 114:









I have finished the ticklers:



And lengthened the magneto strap, this Bosch is way taller than the standard Magneto France item...



Bye for now, Patrick
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Offline thefrenchowl

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Magneto earthing post:









Patrick
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Offline thefrenchowl

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Hi,

Been pulling off the cam followers guides so I can bring the cylinder and timing cover to my machinist to have the deck just skimmed enough to have it flat within a thou and dead parallel with the cranshaft...









   
Patrick
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Offline thefrenchowl

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Got all my sand blasted bits last Friday, so time spent in the garage went up!!!


   


I bought a can of cellulose varnish and a can of cellulose silver... Started experimenting with the varnish directly brushed on the parts, nive grey look, reminds me of the XR1000 paint job...







The record breaker forks were streamlined with chatterton, a kind of cloth reinforced sticky tape. To achieve that, the inside spaces of the forks are filled with balsa wood... Here we go!!!





Quick experiment with gaffer tape, no good!!!



Patrick
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Offline Doc B.

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For what it's worth, here is a pic of what you might be looking for -

http://velobase.com/ViewComponent.aspx?ID=b9ba29b7-0206-44bc-9fd1-23647df22b62&Enum=103



The closest currently made thing might be hockey stick grip tape.
« Last Edit: May 25, 2018, 09:48:03 AM by Doc B. »

Offline thefrenchowl

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 :-D Yep, Doc B, that's the thing!

I'll look for some... Needs to be silver colored...

Thanks for the link.

Patrick

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Offline Doc B.

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If this stuff was made in the 30's I would imagine the silver color might be something like butyrate dope over the cotton.

Maybe you could paint it?

https://www.amazon.co.uk/Chatterton-Fabric-Adhesive-50mmx50-panastore/dp/B06X9GV9B1