880 Norton Sprint Special - "real - time" build, lots of photos

This bike is a collection of stuff I bought from Kenny Dreer (original instigator of the new Norton) as he was selling off his operation to Stuart Garner. I've had it sitting on the shelf for years, then slapped together a rolling mock-up and tried to sell it to get some play money to finish other projects, thread is here

Since nobody was interested in that deep of a project, and since I re-opened my shop after getting screwed at my paycheck job, I decided to tear it down and build it out. This is a "catch-up" on the project that started back in February...





As a rolling mock-up, it was missing several major components including crank, transmission, isolastic mounts ($$) and lots of little stuff. But, it gave you a good idea what it might look like.

Here's a much better example of what it will look like (but without the excessive drillings)-



There is no question in my mind that this bike will EASILY be able to do the Ton!

Re: 880 Norton Sprint Special

Now that the build is at a significant milestone, I'm fairly settled on the specifications:

Engine: '74 Norton 850 cases, VR (Dreer) 880 big-bore kit w/ JE pistons and gapless rings, RH4 head, Sureflex lightweight clutch plates, polished covers, new & Cad plated hardware. BAB reed valve positive crankcase ventilation. Rebuilt 4-speed transmission. Rebuilt Amal 932 Concentric carbs, crossover exhaust headers, Dunstall replica mufflers.

Chassis: '74 Norton Commando frame, VR "big bearing" transmission cradle, box-section swingarm, vernier adjustable isolastics, all chassis parts powdercoated glossy black, all fasteners new or Cad plated originals.

Suspension: Yamaha XS650 front end, polished lowers, new seals, Cad plated hardware. DOT classic adjustable shocks.

Controls: Clip-on chrome handlebars, UJM master cylinder & clutch lever, Dunstall style rearset fold-up footpegs with rubber covers, 1/4 turn throttle.

Wheels, brakes & tires: Overhauled Yamaha front wheel with single disc brake, Blanchard ground & drilled. Rebuilt Honda CB750 rear wheel & SLS brake with polished cover and polished alloy torque arm. Cheng Shin tires in good condition.

Bodywork: VR880 Sprint Special fuel tank and "boat tail" seat with original VR paintwork, fiberglass sidecovers, painted to match.

Lighting & electrical: Ducati Monster headlight & mounting bracket, VR tail light built into seat/tail. Lucas RITA electronic ignition, Tympanium electronic regulator/rectifier, Baja Design control cluster, individually fused, hand wired electrical wiring system.

All in all, this bike will start easily, idle well, run very well up to 7,000 RPM, handle very well, brake well, and look good.

Re: 880 Norton Sprint Special

Cool. I'm in.

Re: 880 Norton Sprint Special

As typically happens, I know I have a certain part on the shelf somewhere, so I go looking for it. In the course of looking for part "A", I stumble across parts "B", "C", and "D" that I needed for other projects!

Today, while looking for throttle parts, I found a complete Sparx electronic ignition (looks new), a second Sparx unit (used, but I wouldn't have kept a non-working one when I get free warranty replacements), and a pair of new-in-the-box Emgo dual lead 12v coils. I trust the Sparx ignition much more than the old Lucas unit, so that's a done deal. The second Sparx unit & dual coil will go on my Triton project.

I also found a brand-new-in-the-box drive chain, a Ducati throttle from my son's Monster (same one that donated the headlight), new throttle cable assembly (one cable segment plastic sheath is cracked), a new tach cable and a real nice almost new clutch cable. I had to chop the old throttle cable off and slit the cable adjuster to install the 1-into-2 Norton throttle cable, it came out nice and clean.

After sorting those parts out, I made a quick run down to the local all-brands bike shop (Johnny Gregory's) and bought a set of fork seals and some nice superbike grips.

...and now, back to the build from earlier this year.

Re: 880 Norton Sprint Special

I had high hopes of using a rare set of VR 880 engine cases that are beefed up on the primary side (the side that always blows up), but they are very different from standard cases, and are meant to be used with VR primary cases, belt drive, and electric starter, so the alignment and spacing of the parts does not work unless you use ALL VR parts; it's especially problematic with the big bearing conversion and box-section swingarm as it's all a bit wider than stock. Since this bike doesn't have belt drive or e-start, and I'm not willing to use my carbon fiber primary case (1 of only 3 ever made), I'm going to use the set of 850 cases with a hole in them (I have a VERY good welder). I gave it a valiant effort and tried to modify my leftover set of primary cases, but I stopped short of cutting into them to try to make them work.

I also waited a little too long to buy a complete built up crank & rods from Kenny that would have been perfect for the 880, so I'm resorting to the best of 3 standard cranks I have. My budget doesn't allow me to shell out for a nice cam, so I'm using the stock 850 cam.

Pistons are VR 880 dished-top, made by JE, with Total Seal gapless rings, kinda blingy but VERY nice



The head is a very good condition RH4 with none of the typical cracking between the guides, and no typically stripped exhaust port threads. It was pretty scruffy, but I gave it a proper scrubbing in Simple Green (fantastic solvent/degreaser)

before


after


So that's pretty much it for the basic power unit.

Re: 880 Norton Sprint Special

The front end is from a 70s Yamaha XS650 (72, I think). I pulled it off a guy's Bonneville to return it to stock with original Triumph forks, and he gave it to me in partial payment).



Forks were not leaking and brakes worked well enough, but they're getting totally overhauled including polished lowers, new seals, caliper rebuild, disc ground & drilled, etc.

Rear wheel will be from a Honda CB750 four with total cleanup and polished cover (shoes and bearings are in great shape)



The axle will take some adaptation as far as the spacers, should be a piece of cake.

Re: 880 Norton Sprint Special

I've had these nice Dunstall style rearsets on the shelf for a few years, Z-plates will be polished-



Another purchase I didn't need, but were too cheap to pass up a few years ago - Amal 932 concentrics in excellent shape with extended tickler buttons (no stink finger).



This is a complete original Lucas RITA electronic ignition system



As mentioned earlier, it is redundant now after finding the new Sparx unit.

Re: 880 Norton Sprint Special

BAB reed valve crankcase breather to eliminate oil leaks and let the engine spin a bit more freely, instead of acting as an air compressor on the piston downstroke. I salvage these from modern bikes and adapt them to the Norton Commandos



Dreer VR880 "Big bearing" cradle & box section swingarm, with provision for e-start mounting. This does away with the wimpy swingarm spindle on bronze bushings that typically wallow out the mounting tube on the tranny cradle resulting in very bad handling to the point of being dangerous



Note the adjustable isolastic mount (upper left of the tranny cradle), and the aluminum rear brake torque arm, both bits I've had on the shelves for many years with no particular use for.

Ducati Monster headlight and mounting bracket salvaged from my son's 900 after he converted it to a street fighter with tiny modern headlights

Re: 880 Norton Sprint Special

I got this clean '74 frame from a guy that managed to sent it to me through U.S.Postal just the way you see it here; the best part? it was only $35 postage!



Next, I needed a crank, tranny, clutch, cam and rods; so, I bought a donor engine



FedEx somehow managed to crack the rear of the timing case off, so they refunded the shipping cost plus cost to repair. Bottom line, I got the engine for about half what it originally sold for. In the photo, the broken part is sitting in place.

Since the engine was very sadly rusted, the first thing I did was use up a can of WD40 ALL OVER it, then popped open the tranny; no suprises, everything in surprisingly clean shape inside



Oh, yeah, I've seen WAY worse. This thing will look almost new when I'm done with it.

Re: 880 Norton Sprint Special

Pistons were virtually welded to the bores. Lower end had no oil in it to preserve it



I'll be extracting these cam followers ("lifters") and using them



Borrowed a friend's 4" POSI-LOCK puller, my 3" isn't up to this heavy task with so much rust. Note the broken-off rear section of the timing case



Half the battle is over!

Re: 880 Norton Sprint Special

Rod bearing shells were actually in good shape-



Crank journals are in great shape, thanx to rod bearing shells doing thier job (note the special British bike crank pinion puller tool)

Re: 880 Norton Sprint Special

Since some of the parts on the first donor engine weren't going to be easily usable, and there was no circlip to hold the clutch diaphragm spring in, I cruised e-bay and ran across another donor engine WITH a frame & swingarm. Coincidentally, it was relatively close by (Houston), and I already needed to go to Baytown to collect my roller starter that I had loaned a guy. We made a vacation of it and went to Galveston beach (insert "thumbs down" icon here). The water looked like chocolate milk, and the crowds were ridiculous. Still, we got in the water and had some fun with the kiddos.

Donor lot 2-



All of the cam and drivetrain parts, as well as all of the clutch, are in excellent shape.

Here's the "field fabricated" positive crankcase ventilation system



So, Donor engine 1 will give up the crank, rods, transmission, primary cases and rockers. Donor engine 2 will give up the cam & drive, clutch, cases (after welding), oil filter assembly, and the clutch lifter bits that were missing on donor engine 1. Donor engine 2's transmission will give up it's guts and covers to my VR gearbox for the day I finally build my VR engine for the blue monoshock bike (it's running a plain vanilla 850 e-start right now)

Re: 880 Norton Sprint Special

This is what the inside of the blown 850 engine looked like-



Mangled rod bearing shells, hunks of broken rod, and part of a snapped rod bolt with nut still in place. None of the rest of the remains came with the engine. Note Bud Light beer bottle cap and some leaves; I think this engine was being used for a trash can...

Re: 880 Norton Sprint Special

This journal was not too bad off after I removed the remaining rod; the blown side is rough. Good thing I have the other crank.



Sludge trap inside the crank has some serious grunt in it-



A little size perpective on the sludge, look at the crank cheek nut

Re: 880 Norton Sprint Special

(August 1, 2015)

Complete set of rockers with shafts, Thackaray springs and shims from donor engine 1



Inner primary cover from donor engine #2 with chewed up oil fling lip dressed for repairs



Front brakes had sat a while and were as mess-



This is how I extracted the stuck outer puck - tack welded a bolt inside the outer perimeter, grabbed it with vice-grip pliers, turned & pulled. Then just broke the bolt out with a chisel and dressed it up with the belt grinder.



Fork internals "before" (upper), and "after" (lower)

Re: 880 Norton Sprint Special

Parts getting ready to be polished (connecting rods and rear brake torque arm not shown)



Unable to round up all the specific bits that will be powdercoated, this stack represents the same items: Frame, tranny cradle, swingarm, fork yokes, battery tray, front mount, top mount, coil mount, sidestand, centerstand and handlebar mount caps. Pictured are Commando fork yokes which go silver; I'm using the Yamaha yokes which will be black.

Re: 880 Norton Sprint Special

Crank from donor engine 1 (750). Journals should polish out at standard size.



Not too much sludge in one side, but you CANNOT leave old sludge in a crank, as it will dissolve and trash your big end bearings and/or the crank journals.



Sludge in the flywheel trap

Re: 880 Norton Sprint Special

(Aug 5, 2015)

Other half of the crank, similar sludge buildup. Ready to have the crank boiled and polished.



I made a trade of the 1st donor engine's 750 cylinders and a set of formerly new OEM .020 over pistons & rings that had been in their box as it perished over who knows how many years; they'll clean up by hand with a detailing brush.

What I got was a set of very nice Roadster sidecovers, an ignition cover cap, and a tach drive (the last 2 bits will go on my personal 880 engine build)

Re: 880 Norton Sprint Special

(August 8, 2015)

Curious, I noticed all 4 inner springs are exactly the same length as all 4 outer springs: 1.688"

Book says - Outers: 1.618, Inners: 1.482. Hmmmmm.... Maybe a set of aftermarket springs? I have 4 decent sets of OEM springs that don't vary by more than a couple of thousandths, but I'd like to use these if there is any benefit.

Cam is a "breather" type with no markings. I suppose I need to carefully mic it and see what it might be (if not original)



Photo record of the orientation & relationship of the hub to the front brake disc; re-assembling them wrong will mean the rotor is way out of alignment



A very happy coincidence - I am able to turn down the Yamaha yoke stem ever so slightly and it will fit in the standard Norton sealed steering bearings. Also, the same bearings will work perfectly in the Big Bearing / box-section swingarm with one slight change to my original plan: I need to use heavy wall (oilfield) pipe for the bearing seats, and turn down the I.D. ever so slightly to have them be a light press fit. Finally, the local bearing house had them on the shelf for under $25 each! (about half of list price from Norton parts stockists, not to mention no shipping charges)

Re: 880 Norton Sprint Special

(8/8/15)

I'm nowhere near the 166 pound limit for the Cad plater's minimum charge/batch; only up to about 30 pounds and I've already cleared through 3/4 of the shop, digging through bins and shelves...

Yes, I know, some of the sprockets are a little too fishooked to use; I'm going to run through all of the gearing variables before I settle on the final drive ratio. THEN I'll order & install a fresh new one.





















Still way below the minimum, may as well toss in my son's lug nuts from his original Corvette wheels stashed in the corner