I did the electrics on this bike, it is the most complicated electrical I have ever done and even seen on a British bike. There are 5 fuses, 3 relays (not counting the flasher relay). Boyer microdigital electronic ignition, Sparks 3 phase alternator, LED taillight, halogen headlight, FIVE (5) idiot lights indicating flashers (2), pilot light on, high beam and a spare. CNW electric tach and speedo, oil pressure gauge, oil temperature gauge and voltmeter.

What sets it apart more than anything else, is the 80° crankshaft which is supposed to make it as smooth as a Ducati or a 4 cylinder UJM. The guy did a lot of work himself, especially putting it all together. It's a nice bike, but everything is so tightly packed together it's a nightmare to work on. For example to remove the left hand panel, the seat has to be taken off and then the clip can be maneuvered with fingertips, after that you need to have your hands massaged because of the cramps.

I have a 1Mb (well a bit less) sound file of the engine running if anyone is interested in hearing how it sounds. Send me a PM with your e-mail and I will send it off. It sounds a bit like a Ducati, at least that is what I have been told, the sure thing is it doesn't sound like any Norton you have ever heard.

Jean

Beautiful, very nicely done Jean. i'd love to hear it running. piztonbroke@aol.com

Wow! The more I look at these pictures, the more neat tricks I see! Where did those barrels come from? The work on the left front fork lower is neat! As is the rear brake master cylinder mount. Very unobtrusive.

Sweet machine.

1. how much did that angle in the carb boot reduce intake efficiency?
2. 80°? Where did that figure come from?

Great mother of Norton. What an amazingly meticulous machine.

I like it "okay".

I would offer more than my customary $350.00 for it, if it was for sale.

Are those Yamaha SR 500 wheels? Looks GREAT!!!!!! WOW, How much were the clocks? Chuck.

I only did the electrical system on this bike, it's not mine, there is a lot of neat stuff though

To answer a few questions:

The 80° angle was determined to be the best for a Norton by the guy who does the crankshaft modifications, for a Triumph, the angle is not the same. There is an article about a 90° cranked Norton in Classic Bike Guide (August 2003). The guy who does the 80° crank is from Toronto, check out his web site at http://www.offsetcrank.com/index.html How he came to 80°, you will have to ask him. On his site there is mention of 74°, 80° and 90° of offset, I think he says the 80° is the smoothest.

The carbs are from CNW, including the spigot, IMOHO, not any worse than the stock Norton way to mount their carbs.

I think the barrels came from British Cycle in Nova Scotia http://www.britishcycle.com/ The owner of the bike told me they were an old set British Cycle had and he got them at a discount but he had to do a lot of fitting to get them on because nothing lined up.

The wheels are Morris mags the owner bought in the seventies.

Jean

In general, the discussion on offset crank angles falls into 2 theoretical categories:
1. 90° produces the best balance of motion between the 2 cylinders - this will always be 90° regardless of engine design, etc.
2. the point where 1 piston is stopped, and the other piston is at maximum velocity (its rod is at 90° to the crank) - this will vary based on rod ratio. The original Triumph design used 76° because that's where the 2.01:1 rod ratio places the throw.
The crank offset angle = 90° minus the maximum thrust angle.
Maximum thrust angle: arc tan (1/(2*rod length)/(stroke length))
The Triumph 650 rod = 6.500”, stroke = 3.228”
(2*rod length) ÷ (stroke length) = 4.027
1 ÷ 4.027 = .2483
arc tan .2483 = 13.94
90 - 13.94 = 76.06°, hence 76°

The Norton rod = 5.875”, stroke = 3.504”
(2*rod length) ÷ (stroke length) = 3.353
1 ÷ 3.717 = .2982
arc tan .2982 = 16.60
90 - 16.60 = 73.40°

80° may have been used (and there are numerous comments that the angle isn't critical to vibration reduction; Yamaha 650 uses 83° because it's almost a bolt-in), but Geoff Collins (who made the crank in that Norton) recommends 90°.

Love to hear it, chuckinton@aol.com Thanks, Chuck.

panic wrote:In general, the discussion on offset crank angles falls into 2 theoretical categories:
1. 90° produces the best balance of motion between the 2 cylinders - this will always be 90° regardless of engine design, etc.
2. the point where 1 piston is stopped, and the other piston is at maximum velocity (its rod is at 90° to the crank) - this will vary based on rod ratio. The original Triumph design used 76° because that's where the 2.01:1 rod ratio places the throw.
The crank offset angle = 90° minus the maximum thrust angle.
Maximum thrust angle: arc tan (1/(2*rod length)/(stroke length))
The Triumph 650 rod = 6.500”, stroke = 3.228”
(2*rod length) ÷ (stroke length) = 4.027
1 ÷ 4.027 = .2483
arc tan .2483 = 13.94
90 - 13.94 = 76.06°, hence 76°

The Norton rod = 5.875”, stroke = 3.504”
(2*rod length) ÷ (stroke length) = 3.353
1 ÷ 3.717 = .2982
arc tan .2982 = 16.60
90 - 16.60 = 73.40°

80° may have been used (and there are numerous comments that the angle isn't critical to vibration reduction; Yamaha 650 uses 83° because it's almost a bolt-in), but Geoff Collins (who made the crank in that Norton) recommends 90°.

Nice math. I always thought the Yamaha was a 180° design, but read this http://www.sense.net/~blaine/270.html they talk about how the cranks are linked together with a 13 spline "coupling", that is where the 83° comes from. The Yamaha is a 360° crank from the factory, mainly for the music it makes I guess

Jean

I looked at pictures of Yamaha 650 cranks and they are indeed 180°, who would have believed something written on the internet could be wrong, what is this world coming to?

Jean

Re: " Yamaha 650 cranks and they are indeed 180°"

Referring to the SOHC XS-1, XS-650 parallel twins, all of which were 360°.

I agree with panic, the XS 650 cranks were 360°. (Haynes XS 650 manual mentions it and the manual photos shows it has a 360° crank).

impressive!

L.A.B. wrote:I agree with panic, the XS 650 cranks were 360°. (Haynes XS 650 manual mentions it and the manual photos shows it has a 360° crank).

Mmmmfff pffff (gee it's hard to speak with feet in mouth )