1973 Norton Commando 850, Dunstall, Opinions needed.

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bwolfie

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So here is the short of the story. 14 years ago, while I was in A&P school, I recieved a FREE Norton Commando. Having owned several Jap bikes, I thought cool, how bad could it be. Well the engine was literally in a milk crate. The frame had a horrible penut tank and a horrible chop job. So bad that the front mounting tabs were 2" too far back. Typical harley 15 inch rear wheel, King and Queen quilted seat, extended fork tubes, and tons of rust on the frame, sandblasted and left to sit in the basement. Did I mention it was Free. So being young and stupid the saga began. I did the right thing and purcased a parts catalog and service manual first. Went thru all of the parts, kept all the real parts, and sold off the rest. Then several years of E-bay, the local cycle shop basment, and local british shop, and a few mail order sites it was starting to look like a bike. I have had steller luck buying and selling parts, often keeping what I want and turning a profit. About 3 years ago I got it on the road, exactly 100 miles in the bottom end went out, piston, rod and crank, the bottom end was the only thing I didn't work on. So here is where I sit, 2 kids later and I am determined to get it back on the road in the spring. As it sits here is what I have. Full dunstall body work, fender, 1/4 fairing, tank, seat, exhaust, mufflers, clip-ons, self made crossover rearsets, MKIII rear disk brake setup, MKIII battery tray, Excel shouldered rims, SS spokes, Avon Venom's, 32mm single Mikuni. So here I sit at the cross road. I have some I deas of what I want to do. But would like some opinions. Things I would like to do:
Front progressive springs
Tapered steering bearings
Belt drive primary
Ultimate folding Kick lever
2S camshaft
Beehive valve springs
Now here is the difficult part. I have the stock barrel .020" over, ready to install.
But I also have a Dunstall aluminum barrel, 810cc's.
I am thinking of modifing it to fit on my 850, it's been done before. I am thinking of doing a 920 kit to it, it will fit but be close.
I have also concidered a standard 850 kit.
Whichever I choose I am going to make the 6 thru bolts on it for strength. also some welding between the fins to make the bolts work.
So any opinions, likes, dislikes,advice, reality check. I am not racing the bike, just trying to be different.

Thanks in advance, Brent Wolff, Franklin, WI USA
 
I also have lightened and polished rocker arms, finned valve and point covers, Boyer ignition with dual ouput coil.

I am also planning on changing to dual 32 mm carbs, hopefully shortly after I get it all running.

I would like to only do the motore in one shot, I'm not going to be pulling it out for a long time,

I have had enough of that with my 75 XS650 750cc kit, 3rd time's a charm.
 
Personally I would throw the Dunstall cr"p in the bin like the 5 I disposed of!! If you want an ally barrel, get a Maney one, it won't break, split around the middle, drop liners, leak and all the other inbuilt "features" of the Dunstall kit!
 
I'm with Seeley. I saw one recently that a guy thought was a bargain, pumped a heap of money into and then discovered it was cracked. I now am 1300 odd miles into my Maney barrels. Work a treat and much lighter.
 
bwolfie said:
Tapered steering bearings
Click to expand...

The original 1971-on non-adjustable sealed ball bearings are probably one of the few items that give the least trouble on a Commando and provided water hasn't managed to get into the bearings somehow, then they appear to be practically everlasting-and of course they never need adjusting, so replacing them with tapered bearings is unnecessary-in my opinion.
 
1. Front progressive springs...If upgrading to Lansdowne Fork Kit, stock springs are advised. Measure yours up to see if they are in spec. 18 3/4"
2. Tapered steering bearings...Lab has made this clear.
3. Belt drive primary.... This is a good thing. There's a lot of good kits out there, do your research.
4. Ultimate folding Kick lever...... watch out for clearance if you plan on RearSets.
5. 2S camshaft........I your not racing then Stock cams have proven to be great, but if you still want to be different, think about Megacycles 560NR.
My2cents
 
Sofar,

Leave head bearings alone.

The megacycle cam is out of my price range, the 2s is $225.00, the megacycle is $400.00, and my stock cam is junk.

I'm going with the RGM belt kit, $325.00.

I've decided to sleeve my Dunstall barrel with 850 liners, run 6 thru bolts, resurface lifters and weld between fins for thru bolt strength.
For my application this should work fine, the manley barrel are just too pricey for what I am using the bike for. 850 liners are like $40 each,
so not much invested there. I'll have about $250 into it when it's finished. I like the weight savings, and the look of it.

The folding kickstart lever should work out fine with the rearsets I made, no matter what I have to fold up the foot peg.

That's it for now, I'm working up my shopping list, trying to sell a few more things, and moving the bike into the basment work shop. I have a walkout basment, so that is an easy one.
 
Get it crack tested first. It'll be worth the trouble to make sure. No guarantee it won't crack later of course.
 
I"m assuming the 850 liners you refer to have a lip (flange) at the top, not just a straight sleeve. I've seen the stock iron cylinders sleeved successfully with straight liners, but they won't stay in position in an alloy cylinder.

The Dunstall cylinders deserve their poor reputation, but I wish you luck with them.

Ken
 
bwolfie said:
Sofar,

Leave head bearings alone.

The megacycle cam is out of my price range, the 2s is $225.00, the megacycle is $400.00, and my stock cam is junk.

I'm going with the RGM belt kit, $325.00.

I've decided to sleeve my Dunstall barrel with 850 liners, run 6 thru bolts, resurface lifters and weld between fins for thru bolt strength.
For my application this should work fine, the manley barrel are just too pricey for what I am using the bike for. 850 liners are like $40 each,
so not much invested there. I'll have about $250 into it when it's finished. I like the weight savings, and the look of it.

The folding kickstart lever should work out fine with the rearsets I made, no matter what I have to fold up the foot peg.

That's it for now, I'm working up my shopping list, trying to sell a few more things, and moving the bike into the basment work shop. I have a walkout basment, so that is an easy one.
Click to expand...

the 2 s cam is NOT what I would run especially with a low compression motor . look on e bay for a good stock cam.

as for the junkstall barrel I am with the others the best place for it is the scrap pile!!! been there done that. you would be money ahead to do an 880 kit in the 850 barrel. just make sure to find a good set of light weight pistons. the ones that TC Christinsion sells is to heavy. I am also NOT a fan of the 920 kits as IMHO it takes to much material out of the and the barrel.
 
Seeley920 said:
Personally I would throw the Dunstall cr"p in the bin like the 5 I disposed of!! If you want an ally barrel, get a Maney one, it won't break, split around the middle, drop liners, leak and all the other inbuilt "features" of the Dunstall kit!
Click to expand...

I'd second that. If you want a museum piece, use the Dunstall barrels. If you want a runner turn it into a paperweight.
 
Seeley920 said:
Personally I would throw the Dunstall cr"p in the bin like the 5 I disposed of!! If you want an ally barrel, get a Maney one, it won't break, split around the middle, drop liners, leak and all the other inbuilt "features" of the Dunstall kit!
Click to expand...

Wow, I thought I was the only one that thinks Dunstall stuff is Cr*p. In 2002 I drove for three hours to purchase a '74 JPN. The seller also showed me a '72 810 Dunstall full cafe racer for sale. I had enough money to buy one. My opinion of Dunstall quality made the decision fairly easy.
 
I've had a couple of cams reground by RGM and I am satisfied with the results. They can also weld and re-grind a standard cam to any desired profile for a modest extra charge compared to a standard grind.
 
bwolfie said:
http://i1029.photobucket.com/albums/y355/brentwolff/Norton%20re-build%202010/101008_143636.jpg

Started working on the Dunstall fairing. Got my gauges mounted and carbon fiber done.
Click to expand...
Are you making these completely out of carbon fiber or just repairing the originals? Is it hard stuff to work with? I guess it can't be worse than fiberglass but how costly?
 
Actually the carbon fiber is easy for me to use, and what I have used so far was free. I am using it as an overlay for strength and looks. I am an aircraft mechanic, I used to do carbon fiber repairs.
 
Update:

Bike is in my basment workshop, completly in pieces.

I am using the stock frame, modding to mono shock and integrated oil tank.

Making front engine mount, trans cradle and swingarm out of aluminum.

With the time I have to work on it, and the amount of work it needs, i think this is a comprimise I can live with.

I am switching to a belt drive, so I can ditch the primary, and make an aluminum sheetmetal cover.

I am still up in the air about the barrel. I'm going to get the liners as soon as I sell some more parts. So we'll se how it turns out.
 
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