'64 650SS Downunder

I'm in the process of rebuilding a 1964 650SS that was imported from South Africa to Australia about 3 years ago.
It is my dream rebuild but also gives me some distraction time whilst looking after my better half who is very unwell at present.
I'll start with a few shots of the motor (test assembled without pistons or timing gear) together with some info on the motor to date (I'll post more later as time permits):
* The crankshaft is in good condition, original journals size so I disassembled, cleaned, rebuilt and had dynamically balanced to 65%.
* The conrods were mismatched so got some good commando ones of evilbay.
* Pistons and rings are good, like new - first oversize
* Carbs are original - with June '64 date stamped on flanges. Thought they would need resleeving as slides were quite loose. Got new slides from Burlens and they wouldn't fit, it worked out the bodies were out of round - a bit of careful "oversqueezing" with soft timber and clamps and they're like new!
* Main bearings only had 0.001" shrink in cases. This together with the fact that I want to fit lower rear reed valve crank breather (Jim Comstock design/idea) and did not want to adulterate the matching numbers casings meant a hunt for an "orphan pair". Eventually found some on evilbay that gave 0.0035" shrink on bearings (they're 1960 numbers - so at least a bit of Bracebridge Street on the bike)- you'll notice the oblong ports (bigger to minimise pressure loss) and tappings for the reed valve in the closeup rear photo.
*Using superblends, shimmed the outer races to 0.010" crank endfloat
* Spent some time with 1/4" drill and various dremel bits removing extraneous casting sprue?? from airways between cylinders on barrel and through head. Cooling very important here in tropical Queensland. Amazing how much more "open" they look.
* Base of barrel I blued - scraped - filed, blued - scraped - filed, blued - scraped - filed, blued..... 4 hours of work later the many gaps between crankcase and barrel were reduced from 0.008" to only a couple at 0.001" - 0.0015". I figured this is good enough. Will use Loctite 518 without gasket for this joint. Just painted the barrel with hight temp engine enamel and baked in the oven for an hour.
* Had K2FC magneto professionally rebuilt - but cam ring was not concentric with shaft (not happy!) but texasSlick's advice on the site helped - all good now
* I think I might have a fetish for fasteners (not quite as bad as the carb bolt vs stud thread though) but in my eye Dominators look "right" with slotted screws in the right places - work well too if you use the correct size screwdriver,
* Homemade engine stand looks a bit sad but will have to do as I can't weld
Anyway, as I said above I'll post more as it progresses
Cheers
Rob

Very nice work.

I would think hard about the velocity stacks. Shame to ruin that nice new engine and carbs with grit from them dusty roads.

Maybe at least put a sock over them if not run some pods.

Yep - I do agree
I have the "standard" norton" filter box but feel that it visually spoils the bike (narcissistic me!) so am examining making a filter box that fits between the oil tank and battery box.
Was talking to Ken McIntosh about this a while ago and he told me stories of stones breathed in and denting the pistons on some of his racing bikes - but then his bikes are pulled apart often.
My Dad, Reg Craig (1932 - 2000) told me a story about riding one of Ken's works Nortons (1937 500), with Ken on a more recent bike (1950s) from Ken's shop to Pukekoe racetrack, open megaphones and doing around 80-90 mph when cops, lights flashing etc, came alongside. They must have realised they were no ordinary hoons (revheads, boy racers or whatever you call them in other places) so signalled them to follow and upped the pace to 100mph. Then waved them goodbye as they approached the track. Talk about excellent service by public servants!
Wish I lived in NZ
Cheers
Rob

Firstly, may you indeed be comforted and distracted as your wife endures her distress; all the best wishes for her condition going forward.

What a beautiful lump. Just a peach.

A question about rockers and oil feed...
I have just disassembled the head and found the following - looking for comments as to suitability.
1. Oil feed is from timing cover, oil pump is 3 start
2. Rocker shafts are scrolled, with flats facing inwards (toward spark plug) as installed by PO
3. Instead of stock (I believe for '64 650SS) outside thrust washer (81802) and inside spring washer (81803), on the rocker shafts, there are hardened steel washers/shims of varying thickness (from 0.028" to 0.138")
4. The rocker valve adjusters fit squarely on valve heads (when valves are closed)

I realise there is a lot of information on this site relating to this subject but I found id difficult to sort Commando stuff from others
Any advice welcome
Cheers & Happy New Year
Rob

robs ss said:

A question about rockers and oil feed...

2. Rocker shafts are scrolled, with flats facing inwards (toward spark plug) as installed by PO

Rob

Click to expand...

The flats should face outwards not inwards,( towards the valve covers.) at least on a Commando engine.

With scrolled rocker shafts and a 3 start oil pump the flats should face inwards.

Does anyone have comments on the following observations on the details of my cylinder head?
When disassembled I noted:
1. the bores supporting the rocker shafts (both inner & outer) on the drive (LH) side have been bushed using aluminium. The bush ODs are all about 0.620". The outer bushes have obviously needed drilling to allow oil supply from the banjo drilling.



2. The timing side (RH), while not bushed, has had 0.080 - 0.100" skimmed from the milled surface that the rocker shaft covers mate with. it is obvious if you look that the milled surface now extends to the exhaust tappet cover joint.



I can't imagine realistic scenarios where these mods would have been necessary. Could they have been factory repairs to fix manufacturing errors? These heads, once you look at them are incredibly complex things to cast and machine so I can imagine errors or faults would have been likely repaired, if possible.
Any thoughts?
Cheers
Rob

Regarding my previous query on rocker shaft flat orientation...
I've just had a close look and it is now clear that the flat is the oil path between the drilled central groove of the rocker spindle and the offset internal drilling in the rocker supplying oil to the ball which engages the pushrod cup.
This will only work, on my head, with the flats facing inward (toward the spark plug)

Still not clear on the scrolled/unscrolled shafts vs. 3 start/6 start pumps, As long as my scrolled shafts are a good match with my 3 start pump with head feed from the timing cover banjo.
Cheers
Rob

robs ss said:

Does anyone have comments on the following observations on the details of my cylinder head?
When disassembled I noted:
1. the bores supporting the rocker shafts (both inner & outer) on the drive (LH) side have been bushed using aluminium. The bush ODs are all about 0.620". The outer bushes have obviously needed drilling to allow oil supply from the banjo drilling.
2. The timing side (RH), while not bushed, has had 0.080 - 0.100" skimmed from the milled surface that the rocker shaft covers mate with. it is obvious if you look that the milled surface now extends to the exhaust tappet cover joint.

I can't imagine realistic scenarios where these mods would have been necessary. Could they have been factory repairs to fix manufacturing errors? These heads, once you look at them are incredibly complex things to cast and machine so I can imagine errors or faults would have been likely repaired, if possible.
Any thoughts?Cheers Rob

Click to expand...

I think it pretty clear that some previous owner might have removed the rocker spindles while the head was cold-a very bad move. The result the spindles revolved round instead of staying in a fixed place even with the end caps on. Hence the drilling out and attempt to fit “brushes or top hats” which is very difficult to do on the Norton head –because there is NO meat around the spindle hole.
Or perhaps I have misunderstood the question.

I've been test fitting the carbs (376 monoblocs) to the head and would like to pick your collective brains on a couple of issues.
The carbs & spacers are attached by four socket head cap screws as shown below (no I don't want to reopen the issue of what mix of screw/studs is "correct"...)


I bought some 3mm insulators (from Burtons) and as you can see they have excess material both around the edges and in the bore. I have sanded one back to correct shape and wonder... should the edges of these insulators be sealed with something, against water on the outside and fuel on the inside? If so what to use?
Also, is any kind of gasket goo recommended to reduce risks of air leaks at this joint?
The other question is whether to use a thread locker on the screws? They aren't very tight when the carb o-ring is compressed. I obviously don't want to over-tighten and risk distorting the carb bodies. What do others do?
Cheers
Rob

I've always used aluminized silver spray paint to seal the carb insulators. It (more or less) matches the head and intake manifolds and elinimates the possibility of air leaks. It also cleans up easily with lacquer thinner during overhauls.

Hey Rob, How is your build going? If it's anything like your 500 single I would love to see it. Hope your Wife is better by the way. Glenn T. S.

gtsun
Thanks for your kind words about my builds - but no, I haven't really progressed very much further with the 650SS.
My wife succumbed to her illness - she died a couple of weeks after my last post on this thread.
My main project now is helping our daughters (26 & 23) get their mojo's back - and maybe in doing that get some of mine back.

The bike can wait - I tinker a little now and then. I'll post pics as soon as I have something to show
This forum is great - lots of good people with helpful advice
Cheers
Rob

robs ss said:

My main project now is helping our daughters (26 & 23) get their mojo's back - and maybe in doing that get some of mine back.
The bike can wait - I tinker a little now and then. I'll post pics as soon as I have something to show.

Click to expand...

Rob, so sorry to hear the report regarding your late wife; as much as we try to say comforting things, it never seems to mean much when we see it typed out.

Treasure the good times, she lives on in sharing the stories. Glad your daughters are old enough to eventually understand it all, and help you as well.

May you and your daughters be comforted, encouraged, and blessed.

Thanks grandpaul

Oh I'm so sorry. Like Grandpaul said words often fail but know if I could say anything that would ease your pain I would. I hope you & your daughters are well and find some peace. Glenn T.S.

Back looking at the engine and the way forward
I have a question for those with knowledge...
I'm looking at putting and aftermarket clutch (and maybe belt) on this bike
Any views on which is best - Bob Newby, Barnett...?
Cheers
Rob

I've always gotten good service from Barnett clutches. Over the years, I have put them in many different types of motorcycles and never an issue.

Thanks Danno - wish you continued luck with Flood Victim
Cheers
Rob