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MK3 Restomod

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Re: MK3 Restomod

Postby Danno » Tue Nov 15, 2016 4:24 pm

Very nice. Wish the Titanic's frame looked like that. Weather is going to flatline this weekend, so I may not paint until spring.
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Re: MK3 Restomod

Postby lcrken » Thu Nov 24, 2016 2:51 pm

A little more progress. Kind of a "two steps forward and one step back" kind of week, or maybe even the reverse. Anyhow, I made some spacers to move the starter mount and outboard transmission bearing holder .250" to the left, to accommodate having moved the gearbox to the left by that amount. That's when I discovered that I had a lot of interference between the starter and the gearbox shell. It must be a pretty close fit on a stock gearbox shell, and the Quaife shell is much thicker around the top mount. So I thought I'd just pull the gearbox and slim it down in the mill. That's when I got the second surprise. When I made the reed valve breather at the back of the crankcase, I didn't think about the gearbox. Turns out the breather gets in the way of rotating the gearbox enough to remove it. And I can't remove the breather without pulling the engine. I didn't want to go to that extreme again. I've had the engine in and out more than enough times already. So I bagged the bike with a plastic sheet, and went after the gearbox shell with a die grinder. It was an iterative process. I'd grind until I got clearance for one spot, and then find out something else was hitting. It took five tries to finally get it all to fit.

This is the bike ready to start grinding.

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And this is how the top of the gearbox shell looked at the end. I took about 1/8" off the top all the way across, as well as grinding a couple of notches to clear the starter lugs. I also took some material off the starter lugs. Not as pretty as if I'd used the mill, but acceptable. I'll clean it up someday when I have the engine out.

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This is the starter bolted up and fitting properly.

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I also finished modifying the repro Norvil top mount to suit me, as shown here. I narrowed it a bit to be sure it will clear the tank, and also rounded some of the sharp corners.

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I've recently received the 36 tooth front pulley, so I can proceed with assembling the primary side now. With the 68 tooth clutch pulley, I now have a 1.889 primary ratio instead of the stock 2.19. That will reduce the load on the gearbox and give it a better chance of surviving, as well as helping with clutch slip risk. Should have some more progress now, with pictures to follow.

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Re: MK3 Restomod

Postby cjandme » Thu Nov 24, 2016 4:51 pm

Awesome as always! I tend to go off the deep end when rounding off and smooth edges, (to the point of OCD at times). It drives my brother crazy, but hey, when you have it apart, and the schedule permits, there is no better time. :)
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Re: MK3 Restomod

Postby pantah_good » Thu Nov 24, 2016 6:14 pm

Does this look familiar?
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Re: MK3 Restomod

Postby Fast Eddie » Fri Nov 25, 2016 12:52 am

Nice looking starter kit Ken, provides a good outrigger support function too, which is nice considering what you'll be putting through that gearbox!
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Re: MK3 Restomod

Postby lcrken » Tue Dec 06, 2016 9:56 pm

On the carb selection front, I've had a bit of a setback. I was planning to use a pair of Keihin CRS carbs in 37 mm size, which I have left over from the single racing days, but they aren't going to fit. I'm using a pair of Steve Maney's CNC machined manifolds that are matched to the heads, and they are too long for the CRS carbs. I could relocate the throttle drum to clear the tank, but the carbs still interfere with the gusset at the top of the frame. I could make them fit if I made some shorter manifolds, but I don't want to do that. It would be hard to match new manifolds to the head with the bike in the frame, and I don't want to pull it out again. I have a set of 36 mm Amals that I could fit, but I really like the light throttle pull on the Japanese push-pull carbs. Before anyone jumps on me for not being manly enough to handle a stiff throttle, let me pre-empt them by explaining that I've had surgery on both hands and only have about 60% normal strength in them, and at 74 years of age, I now get to add arthritis to my blessings. A light throttle pull is pretty much essential if I want to ride more than a few miles without cramps.

I've checked the other carbs I have, and neither the 41 mm FCRs or the 34 mm Mikuni flat slides will clear the frame. I think the 35 mm FCRs might be the answer, but that means buying new carbs. I've been really trying to use up stuff I already have. I have some other Mikuni carbs, but they won't fit without angled manifolds, and I don't want to do that, so I think I'm stuck with buying the FCRs. Always more decisions to make.

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On the positive side, I got the mag wheels back from the inspection shop, and they are free from cracks. And I have the cert to prove it! I need to touch up the conversion coating, and then paint with a good two part paint (gold), and I'll be ready for tires. Still looking on that front. I've used the Avon Roadriders for several years now, and might go with them, but I'm thinking about trying out the new Continental Go line.

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Re: MK3 Restomod

Postby Son of Siredward » Tue Dec 06, 2016 11:06 pm

I like the CR Carbs Ken! The project is coming right along!
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Re: MK3 Restomod

Postby Fast Eddie » Tue Dec 06, 2016 11:50 pm

Ken, why not just hack the gusset out of the way? I know it would have been easier before now, but if you sheet over everything (again) it won't be to big of a job me thinks.

Even the FCRs with Matts lovely, and shorter, manifold still come close, I would expect you'd still have issues even with FCRs.

Are you going tubeless on those rims? A shame not too take the advantage surely?
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Re: MK3 Restomod

Postby gortnipper » Wed Dec 07, 2016 1:10 am

lcrken wrote:Before anyone jumps on me for not being manly enough to handle a stiff throttle, let me pre-empt them by explaining that I've had surgery on both hands and only have about 60% normal strength in them, and at 74 years of age, I now get to add arthritis to my blessings.


All the sympathy in the world, mate. I have had three surgeries on my hands for Dupuytren's contracture. My hand doc, the best in Auckland, says it is the most aggressive case he has ever seen. He said at 53, my hands are what he would expect from someone 70-80.
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Re: MK3 Restomod

Postby grandpaul » Wed Dec 07, 2016 7:41 am

"It's just a suggestion..."

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Stacks would have to be shortened, easy enough to do.

(they're sitting on my shelf)
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Re: MK3 Restomod

Postby lcrken » Wed Dec 07, 2016 9:33 am

gortnipper wrote:All the sympathy in the world, mate. I have had three surgeries on my hands for Dupuytren's contracture. My hand doc, the best in Auckland, says it is the most aggressive case he has ever seen. He said at 53, my hands are what he would expect from someone 70-80.


Yep, mine were for Dupuytren's too. A light clutch pull, light throttle, and a throttle lock so I can rest the hand once in a while help a lot to keep me riding.

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Re: MK3 Restomod

Postby lcrken » Wed Dec 07, 2016 9:44 am

Fast Eddie wrote:Ken, why not just hack the gusset out of the way? I know it would have been easier before now, but if you sheet over everything (again) it won't be to big of a job me thinks.

Even the FCRs with Matts lovely, and shorter, manifold still come close, I would expect you'd still have issues even with FCRs.


Yeah, I've thought about that. I'm just trying to avoid the extra mess and delay. Wish I'd known it would be an issue back when I was working on the frame. Might still bite the bullet and do it.

Are you going tubeless on those rims? A shame not too take the advantage surely?


Still thinking on that one. The wheels are not made for tubeless tires, so don't have the extra retaining rib, but I ran them tubeless on the race bike without problems. I'll probably try them tubeless, and if they leak too much, I can always add a tube.

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Re: MK3 Restomod

Postby lcrken » Thu Dec 15, 2016 8:53 pm

A little more progress. This is the primary drive and starter system mocked up in final form. I did have to make some changes. Originally, I moved the gearbox over .250" to the left, as I had done on my race bike back in the day. Turns out that isn't going to work here. The ring gear on the clutch basket takes up some of the space on the belt pulley part of the clutch, so I can only move the gearbox over by .125", unless I want to move the engine pulley outboard by another .125"+. I don't want to do that, because that would also mean moving the alternator rotor out that much, making a new rotor nut in the process, and reducing the amount of shaft support for the rotor. It's not that it's impossible, but it doesn't seem like a good plan to me. The extra .125" will give me enough chain clearance for any tire I might want to run on the rear wheel I'm using. I originally moved the gearbox over to allow a wider rear tire, and in the beginning I was planning to have enough room for a modern 17" rear tire, just in case I chose to do that in the future. Giving that option up doesn't bother me much. I still need to keep it at least .125" offset so the clutch basket will clear my wider swingarm at the pivot.

Image

Now I'm back to fabricating a primary cover, and I should be done with this part of the job.

For carbs, I've decided to run the 36 mm Amal Mk2s, mostly because they fit. These are the carbs I've been running on my landspeed Norton, but now I'm going to larger carbs on it, so these are available. I've got a new set of chorme plated brass slides from Burlen for the carbs, and I'm going to try some slightly lighter return springs. That should at least get the bike running. If it doesn't work out, I can always try something different later.

Still waiting to paint the wheels. It's been cold and wet lately, and I haven't had a good opportunity to paint.

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Re: MK3 Restomod

Postby lcrken » Tue Dec 27, 2016 9:48 pm

The 36 mm Amals look like they fit just fine. I went through them and installed new stayup floats and needles. I was going to also fit them with chrome plated brass slides, but one of them is way too tight to use. I think the left carb body has distorted a bit, and it binds a lot on the new slides. I put the old slides back in, and they work with no problems. If I want to fit the brass slides in the future, I'm pretty sure I could fit them with a little bit of sanding in the body. I just don't want the extra delay right now, and I know from using the carbs on the race bike that they will function properly. I'd still like to end up with the lighter throttle pull from modern carbs like the Keihins, but this one isn't too bad. I'm using a Tomaselli throttle that has just enough travel for the 36 mm carbs, so the leverage is about as good as I can get it.

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I'm starting on my third iteration of the primary cover. It's a challenge to keep it tight enough to keep the rocks out but still have enough clearance for the belt, as well as keeping the front as small as possible for ground clearance. I'm probably way overthinking it. Third time's the charm, I hope.

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Re: MK3 Restomod

Postby Fast Eddie » Fri Dec 30, 2016 10:49 am

IMHO that is a sensible carb choice Ken. You know they work and you know they'll be close to being right for your big motor and you're obviously well versed in setting up Amals.

You can always fiddle with fancy carb options later, when the other inevitable niggles have been ironed out. But my guess is this thing will go so well you're unlikely to wan to do so!

Looking forward to seeing the huge steps forward you're making over he holiday period...
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