[Mike 40M]

Starting a thread about my -59 Manx. Should never had bought it 3 years ago, if it had not been raced quite successfully by a friend of mine. We used to ride together on our road Nortons, he on an Atlas and I had a Dommi 99. Learnt a lot from him about race lines and how to stay alive on public roads. For some reasons, I have to get it going asap. Started collecting new bits for it a year ago. In january I started to take it apart. Also got new parts needed. As a motorcycle in pieces takes a lot of space, I started to assemble it yesterday. Frame in good shape, only minor scratches in the paint. Swingarm bushes ok, now greased. Head bearings Ok.
First thing to do was rear mudguard in bad shape., replaced with a new. I think a -59 should have alloy rear mudguard, but as I'll try to set it up as it was when my friend raced it, it got another fibreglass one. Advice and critics welcome.

 

[Cyorg]

No signs of cracks? Good that it is painted and not powder coated.

 

[jaguar]

NICE

We need some more cool content here!

 

[Mike 40M]

Thought it was time to put in engine and gearbox. For those of you who don't are familiar with featherbed Nortons. Front engine plates is no problem if you get some friend or relative to lift engine in place. Rear bottom bolt holding rear engine plates to engine is hidden between lower frame tubes. This means that you have to lift the engine to get that bolt in place. Same applies to bottom gearbox bolt, except that you have to lower engine plates to get the bolt in under the frame tubes. I think you have to put on right engine plate first, then gearbox and left plate last. Definitely a bit of curious engineering.
Now a problem showed it's ugly face. The TTI gearbox was a bit fatter than a normal AMC or laydown gearbox so it hit the frame. The 5-speed modified laydown gearbox from -62 will fit and I put in an ordinary AMC gearbox just to check. Have to think it over what gearbox I'll use. Maybe a Quaife?

I'll try to take better pics in the future.

 

[jalsteve]

Alloy rear guard = yes for all years.

The enclosure type guard tuned up as the Manx engine was not factory assembled with sealer (gasket goo) and just two gaskets. The enclosure guard helps deflect oil and keep the rear tyres less oily. BUT as you have what looks like a new engine oil shouldn't be an issue. In fact most oily rear tyres are caused by over filling the gearbox.

Quaife boxes are narrower across the mounts than AMC and need a spacer fitted. Laydown box (Burman) was fitted up to 1956 the AMC box fitted after till 62. Take a measurement on the laydown box from output bearing face to l/h gearbox mounting face. Do the same on the TT industries box and mill off the excess.

What's the small tab for on the frame, front right side top tube? The frame by the way is GP spec as it has fairing mounts on the headstock, these were an extra.

Q. Why not build the original engine?

Modern hard epoxy paints can be as thinly applied as wet paints and show cracks just like ordinary paint. Getting powder type coats off a frame isn't difficult as solvent strippers like Paramose will move it in minutes.

Good luck.

 

[Mike 40M]

Thank you, luck needed. Most bikes I have had turn up unsuspected problems.
A. Reason for not rebuilding original engine. Time and a strong desire to race it. A bit worried about strength of magnesium crankcase. Prefer not to kill a matching number engine. If it only should do parade laps, maybe. Don't have enough confidence in my skills. No problem with rebuilding Norton twins or goldies, but a lot of respect for the Manx engine.
Sharp eyes, no idea what the tabs are, one on each side, try to take a photo of them.
Gearbox not sorted out yet, had some other things to do.
By the way, got a stud from Andy Molnar, replacing bottom gearbox bolt. A bit heavier but a lot easier gearbox assembly.

 

[jalsteve]

Thank you, luck needed. Most bikes I have had turn up unsuspected problems.
A. Reason for not rebuilding original engine. Time and a strong desire to race it. A bit worried about strength of magnesium crankcase. Prefer not to kill a matching number engine. If it only should do parade laps, maybe. Don't have enough confidence in my skills. No problem with rebuilding Norton twins or goldies, but a lot of respect for the Manx engine.
Sharp eyes, no idea what the tabs are, one on each side, try to take a photo of them.
Gearbox not sorted out yet, had some other things to do.
By the way, got a stud from Andy Molnar, replacing bottom gearbox bolt. A bit heavier but a lot easier gearbox assembly.

If you are running the bike as a 350 and racing then the 6 speed box is best but a 5 will do fine. Too much of a stretch for a 4 speeder on modern circuits with slow corners and chicanes.

The manx engine really isn't difficult to do, its just a fitting job which only requires 2 special tools, hairpin valve spring pliers and head fitting jig. Assuming the engine is fairly good condition other than bore sizing you can feel your way through a build, loose movement in the big end, mains, bevel backlash etc you can determine by feel once you know what it should be. Everything else is common to building any other motor like squish measurement, valve drops and TDC and valve timing. Many years ago this is what I did - go to an expert and get the motor built, they will provide you with a full build spec sheet. Get the motor home then strip it, measure and rebuild again but feeling and measuring all the clearances. Today even doing valve clearances on brit twins I don't use feeling gauges, I just need to know if the adjuster bolt is UNF, BSF or Cycle then slacken off the adjuster, screw down onto the valve finger tight then back off an hour or 2 or 1 1/2!!

The bottom gearbox bolt is pain but you get used to it. Also putting the engine in or pulling it out and engine plate wiggling.

 

[Mike 40M]

Mystery. Why this lugs? Not checked for certain but they seems to be braced to frame.

If an angle grinder on the TTI don't work (not certain if I'm joking), then probably will use the old Arrgardh gearbox #186. By the way, it was Torsten Arrgardh, who insisted that it should have coil springs instead of hairpin springs. I stick to that.

 

[grandpaul]

That is some monkey-motion shifting mechanism!

 

[Cyorg]

If you are not rebuilding the engine... when was the last time it ran and what kind of oil was used? Castrol R?

 

[Mike 40M]

Original engine did some parade laps in -95. Not the faintest what oil was used then. "Spare" engine will hopefully commence run in period next month. Old engine looks good on the outside and moves freely. Only rust on bike worth mentioning is front springs and interior of clutch.Some nuts has got a brown patina. Surprisingly good bolts and nuts for a bike which has spent most of its life in a metric country. Most previous owners must have used proper tools.
Spent the afternoon replacing worn parts in front legs. Tomorrow time for finishing front fork.
Thinking of replacing handlebars and levers with modern parts. Original has obviously had some ground contact. Makes it impossible to fix barends yo them.
Seems I soon have enough original parts to build another bike.

 

[jalsteve]

Original engine did some parade laps in -95. Not the faintest what oil was used then. "Spare" engine will hopefully commence run in period next month. Old engine looks good on the outside and moves freely. Only rust on bike worth mentioning is front springs and interior of clutch.Some nuts has got a brown patina. Surprisingly good bolts and nuts for a bike which has spent most of its life in a metric country. Most previous owners must have used proper tools.
Spent the afternoon replacing worn parts in front legs. Tomorrow time for finishing front fork.
Thinking of replacing handlebars and levers with modern parts. Original has obviously had some ground contact. Makes it impossible to fix barends yo them.
Seems I soon have enough original parts to build another bike.

Personally I would do exactly that, build a full replica and restore the original to original.

Milling the gearbox is a 20 min job.

Just make sure the oil is fully drained from the old engine or flush it with diesel.

Oil for the new engine, I use Miller CFS 10/60 full ester and it is superb. I use this in all plain shell bearing dry and wet clutch engines.

 

[Mike 40M]

Triple crown in place. New small issue. How much oil in fork. Talked with a Norton dommie friend from the good old days without speed limits. He had heard from a racer that a Coca-Cola bottle is right. Can anybody confirm that 192 cc is right amount?

 

[jalsteve]

Fork oil 20 grade. If the damper rods and damper bodies are worn you might end up using 30 grade.

Oil quantity - extend the fork fully then compress without the spring - measure the movement (x) now add 2". Fill the fork till you have an air gap of x+2 make sure the damper tubes are filled but moving the sliders up and down a few times. Don't leave less than 2" Boils law and all that.

Don't use dominator quantity as you don't have an internal spring taking up volume.

So you won't put enough in.

 

[jalsteve]

That's me, on a 86 bore forks filled as above and going underneath an ex works Ducati. He had his knee down, hanging off the saddle all very stylish! Me just sitting quiet and letting the bike do it's job. Hated those leathers though they would balloon up - sort of odd looking. Still it looks like he's been blown off by a fat fucker riding a tractor. Managed to wear a nice little flat on the gear change too.

 

[Mike 40M]

Fork oil 20 grade. If the damper rods and damper bodies are worn you might end up using 30 grade.

Oil quantity - extend the fork fully then compress without the spring - measure the movement (x) now add 2". Fill the fork till you have an air gap of x+2 make sure the damper tubes are filled but moving the sliders up and down a few times. Don't leave less than 2" Boils law and all that.

Don't use dominator quantity as you don't have an internal spring taking up volume.

So you won't put enough in.

Just checking if I got it right,.
Using one of those modern tools for setting fork oil level.
Movement =6". Add 2" equals 8".
With fork fully compressed.
Oil level 8 inches below top of stanchion.

Found not enough 20 oil at home, have to get more.

 

[jalsteve]

Just checking if I got it right,.
Using one of those modern tools for setting fork oil level.
Movement =6". Add 2" equals 8".
With fork fully compressed.
Oil level 8 inches below top of stanchion.

With the forks fully extended.

Are your forks manx length Roadholder? Or road? Manx stanchions are shorter.

Manx are 20.375"
Short Roadholder are 21.843"

 

[Mike 40M]

It's normal Manx forks. Just checked level. 6.5" compressed. Seems that coke bottle idea from a famous Manx racer was a bit on the low side.
While waiting for more oil, I will do a bit of milling of the TTI-box. Alternative would be to make new engine plates with gearbox higher.

 

[jalsteve]

Or just put 200-210mls in of 20grade and not lighter.

Manx forks (late) are really quite simple but work really well, compression is controlled by the holes drilled around the bottom of the stanchion, rebound by the damper tube. IF compression is too soft you can weld up (or braze) up the holes and re drill smaller. I also find than the original Norton multi rate springs are too soft, even when new in the 60's, and the forks need a little more preload especially as we are all a little bigger, leathers weigh more, heavy boots and space helmet. So don't be surprised if they bottom out, just buy new springs, Molnars are good and maintain original ride height. I have tried adding packing on old springs and it doesn't work, ride height goes up and the spring is still soft.

 

[jalsteve]

How is the gearbox fatter, I assumed it was wider across the mounts?

Sometime I have to let the engine plates a little forward of the gearbox to allow the gearbox to pivot on the lower bolt and use all of the adjustment slot. Photo would be good?