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1913 Veloce motor disassembly

November 23, 2010
tags: ,

The motor came apart easily, even with all the dried up grease on the crankcase screws.  I’m now measuring up the various bits, deciding what needs to be rebuilt, replaced or used as is.  The cast iron piston is in very good shape.  Just a few small scrapes on it. 

 

The good news is that the motor is complete, with all parts.  And none are broken.  Some are worn, but that is to be expected.  As this bike will be kept forever, I’ll be replacing bearings, etc as a matter of course.  My kids can fix them again in 30 years when the bike belongs to them.

 

Compare this motor to the 1913 Premier in this article.  Piston is different (three top rings vs one top and one bottom), magneto is out front, etc..   And of course the cams and followers are completely different. 

 

The Veloce motor will look very familiar to owners of a Trusty Triumph!  (PS, if you have a pre WWI Triumph, please contact me via the comments link).

DSC09530

IMG_6024

 

Cams are internal on the camwheels.  Not much of a cam profile, just a fairly simple cut.  But there isn’t much room to increase the lift by changing the profile.  Cam followers are hardened rollers to reduce wear.  As they roll, they do not skid on the cam, which makes both parts last a lot longer.  The ‘16 Excelsior has a similar setup, but with conventional external cam lobes.

 

The upper end of the cam followers (rockers) have a hardened flat that lifts the valve tappet.  Tappets ride in long bronze bushings in the crankcase.  Then the tappets lift the valves.  It all adds up to be a lot of rotating and reciprocating mass, which moves with ever other rpm of the motor.  Accelerating and decelerating that mass takes power!  And each bushing has some friction…  Overhead cams eliminate a lot of this stuff, which only helps their power output.  Desmo types even eliminate the valve springs, which is bit more force, a bit more power.  Ping me if you’d like further details on this stuff.  I’m a bit too busy with the project to do a full article today on OHC benefits.  Some more cam stuff is here.  Or read some of Kevin Cameron’s articles in Cycle World.

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This is a clever method to keep the pinion gear on the end of the crankshaft.  The shaft is hollow with an internal taper, and the draw screw has an external taper.  When the screw is tightened, it forces the crankshaft to flex outward, locking the gear in place.  To time the gear, a small key fits into one of the expansion slots in the crankshaft.  It is basically the same setup that Bridgeport milling machines use to hold cutting tools in the quill, an R8 taper.  Since the screw is held tight in the taper, it does not have to be a left handed thread, which makes it simpler to cut the thread and to source a replacement screw if needed.  You’ll recall that the left hand treaded screw on the Premier came loose in the Mohave desert and did some damage…

IMG_6029

 

One small puller was needed to remove the inner half of the engine pulley from the crankshaft.  When you do this job, be sure to use the correct puller.  Don’t be tempted to use two screw drivers and pry it!  And you don’t have to spend a fortune to get the right tool.  Just $5-$10 at Harbor Freight for a semi-disposable tool.  Better ones are available for a price from all the good tool shops.

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A typical old style side-valve spring compressor made short work of dismantling the valves, springs, and keepers.IMG_6065

 

Still life with pistonIMG_6057

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23 Comments leave one →
  1. Jim Abbott permalink
    November 23, 2010 4:20 pm

    Pete: I’m astonished at the condition (good!) of the internals. Especially the piston. And the advantages of roller cam followers are legion. That’s why I asked the question about the ball ends of the Premier push rods. Did they roll or just skid along.

    Great photos and text too. Thanks, Jim A. Tucson, AZ

    • November 23, 2010 4:30 pm

      hola amigo. On the Premier, the cam follower is basically a 1/2″ ball bearing ball. It is very very hard, and neither of them has worn. The cams have a slight rounded groove from the balls though. On the Veloce, the cam follower spins, which helps the wear on the cam and the follower. But the spinning follower still rubs on its internal support, which is a .25″ hardened pin. Needle roller bearings would be slightly better, but are overkill for this application.

  2. John Jennings permalink
    November 23, 2010 5:30 pm

    Pete

    have just emailed a bunch of photos showing the internals of my 1909 Triumph. Your Veloce is the same except for the name cast on the outside by the look of it. Your machine may also be a more original example than the Harrison Veloce that was best known Downunder.

    Regards

    John Jennings

  3. Richard McKenney permalink
    November 23, 2010 7:41 pm

    Very nice Pete

    And in good nick, I notice the big end pin is tapered both ends, perhaps this was a Velo request as the Triumph 1912 & 1913 are riveted at one end, that will make reproduction a whole lot easier.
    With that number and pulley boss on crank case are you sure she’s not earlier than 13?
    Good stuff Pete you should have her running by this arvo.

    Cheers Richard

    • November 23, 2010 8:18 pm

      Hi Richard. I spotted the different crankpin attach after you mentioned all the trouble you had with yours and the local machinist. Mine seem pretty standard compared to bikes other than Triumph. should be easy to work with. I’m thinking about adding a new pin with rollers instead of the bronze bushing. It seems to be the weak link in these motors.

      I don’t think anybody can be sure that this bike is 1913. I’ve read that the model was introduced in 1910ish. Certainly it was for sale in 1912 and 1913. Probably wasn’t offered after the War. No listing of serial numbers exists. Maybe 100 were made and sold. 2 bikes exist today, counting mine (that I’ve been able to find. There might always be more of them hiding in sheds someplace!)

  4. Paul Venne permalink
    November 24, 2010 12:20 am

    Pete, Was there a paper gasket on the timing cover? Supposed to be? On my Excelsiors it’s always missing but shown in parts book. Neat stuff. Thanks, Paul

    • November 24, 2010 8:46 am

      There wasn’t one on the timing cover, but there was a paper gasket between the crankcases.

  5. November 24, 2010 12:30 am

    Really interesting post.
    As others have commented, I’m very impressed with the condition of the internals – must have been a pleasant surprise (if not a relief!) to see this when you opened it up.

    I’ve never worked on a sidevalve – but I’m starting to see one in my future…

    Looking forward to the next instalment.
    best

  6. Brian permalink
    November 24, 2010 12:03 pm

    I have a 1911 Abindon engine, and the internals “look” the same, but in fact are not interchangable. Re the Triumph, consider youself contacted. Brian

    • November 24, 2010 2:10 pm

      Hi Brian. thanks for the note. I’d love to see some photos of your motor. I’ll send you a private note.

      cheers
      Pete

  7. Geert permalink
    December 1, 2010 11:35 am

    Make sure you don’t put too strong valve springs on with these internal cams, like a friend off me did.
    Are you building a clutchless single speeder ? , the best fun to ride in my oppinion.
    You can also get some extra power from the way you set the cams, as someone I know found out with a Triumph and adjusted it 2 teeth from the orriginal markings

    regards, Geert

    • December 1, 2010 11:41 am

      thanks Geert. Right now the bike is set up as a run and jump clutchless single speed. But I’d like to fit a 3 speed rear hub with a clutch. I’ve had both types of bikes, and the clutch and gears are very useful here in the hills of San Francisco! Can you ask your friend to contact me? I’d like to see what cam timings he ended up with.

      PS, are you the Geert from Nederweert?

      cheers
      Pete

  8. Geert permalink
    December 2, 2010 11:07 am

    The guy with the triumph I only see once a year at a rally, I don’t know him that well.
    I’m not from Nederweert, altough I know him well.
    I did the trick myself with the cams on my single speed bike with King Dick engine I remember that on the orriginal markings the carb. would blow back some petrol out off the intake, so it closed to late as the compression stroke would be starting before the inlet would be closed.
    I don’t remember if I changed it one or two teeth, but the guy with the Triumph told he changed 2.
    I rode my bike a few years with sidecar fitted and than you really notice if it pulls well
    Riding a clutchless single speeder with sidecar is a bit crasy, I know, but at least it is flat over here.

    Geert

  9. Doug Lyon permalink
    December 2, 2010 11:56 am

    Hi Pete, Love the articles! I’m following a similar path to yourself re going backwards in time with the bikes. Just now I’m tackling a 1914 Healing Precision 3 1/2, and the set-up is very similar to the Veloce you’re doing. The engines I have are 1912, but have the same internal camform, tapered crankpin, half-time pinion with (3 slots), tapered screw and key etc. Pistons seem to be anything from 2 rings to 4, some with endpads, others with a bracelet to keep the gudgeon in etc. Two lengths of conrod so far! Paper gaskets to all faces. Can send a few pics if you like.

    A 1914 BSA timing side fits a 1912 Precision drive side in terms of diameter and crank centre, but the mounting lugs are moved. The BSA being de-saxe, this moved the exhaust tappet inboard a bit giving an assymentrical look, but the timing chest is as yours, albeit with 10 mounting screws. A 1930’s Empire Star crank would/does go inside. My Melbourne made frame is a dead spit for the Veloce frame, and may have used Sun lugs exported along with the Precision engines etc.

    I think these guys must have all been meeting up in the Birmingham pubs swapping ideas and flogging their designs around the many makers of machinery around at that time. The similarities are too many to be co-incidence, and I think the creative genius of maybe four or five blokes gave us the whole fledgling reliable motorcycle industry after the Pioneers had started it off. Keeps us amused eh? Keep up the good work!

  10. Brian permalink
    October 2, 2011 5:05 pm

    Hello Pete, I have a 1910 triumph. I have two very high quality photos of the Veloce that was here in Australia, if you would like a copy of them let me know. Cheers, Brian.

  11. Kim Ross permalink
    June 26, 2016 7:01 pm

    Hi Pete, I have a 1913 Indian twin motor and this is my first go round with a motor this old. I can’t find anything out there but a parts manual. It seems like there are just a few people out there that work on these and they are not offering much information. Is there a book out there that might help me to understand more so I can tackle a rebuild on this?

    • June 27, 2016 8:48 am

      The basics will be the same for a 1913 motor as from a later one. Be sure that things like the bearings, bushings and shafts are not too worn out. Cast iron pistons can last for decades, so don’t toss them out unless something is really wrong. Don’t bother putting in modern oil-control rings in the piston. If piston clearance in the cylinder bore is a bit more than ideal, you will probably be fine leaving it as is. A little piston slap won’t hurt things, and new aluminum pistons have a habit of seizing. For things like valve timing and ignition timing, you can either experiment with some test rides, or possibly find some published specifications. Nicholson’s book has good info on pre WWII Indians, and might have specs for a similar motor if not for 1913. Here is a link: http://www.modernmotorcyclemechanics.com/ Another good book for restoring old bikes is by Radco: https://www.amazon.com/Vintage-Motorcyclists-Workshop-Foulis-Motorcycling/dp/0854294724 It describes motor rebuild steps, as well as pinstriping, painting and plating at home, gearbox rebuilds, etc.

      • Kim Ross permalink
        June 28, 2016 7:24 am

        Thanks very much for your reply. I have ordered the books you mentioned and am looking forward to getting them in. I have the original pistons but the rings are gone on one piston. Does anybody make these thick rings anymore?

      • June 28, 2016 11:15 am

        Some car guys have supplies for thick rings, but I don’t know them off hand. I have bought rings from Hastings Rings in Michigan. When doubled up in the piston grooves, they were equivalent to the thickness of the old rings. Call their 1-800 phone number and they can walk you through it in about 5 minutes on the phone. Pretty affordable and quick too.

      • Kim Ross permalink
        June 28, 2016 11:43 am

        Many thanks for taking the time to answer these questions, sir.

      • June 28, 2016 11:58 am

        I’m glad to see another old bike being put on the road! 🙂

  12. Brian Tyler permalink
    June 30, 2016 1:12 am

    I had the same issue on a Harley J, and went the same route as Pete with doubling up the rings, but use a smaller ring under the correct sized ring giving me effectively a “thin ” ring bore contact Brian

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