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Engine and Gearbox mounting plates for C'do engine in F'bed

Discussion in 'Norton Commando Motorcycles (Classic)' started by laurentdom, Dec 19, 2012.

  1. laurentdom

    laurentdom

    Joined:
    Nov 30, 2012
    Hi All / Bonjour tout le monde,

    Has anyone an idea of where I could find eiher the drawings / dimensions of the mounting plates I need or the plates ?

    I plan to have the engine tllted forward by 15° in my slimline Featherbed as in a Commando chassis; I know that Unity Equipe, Norvil, RGM in the UK and Clubman Racing in the USA can supply the plates, but I don't know which one to choose or if I would have better making them myself.

    Any advice or experience welcome. Merci !!!

    L.
     
  2. Matt Spencer

    Matt Spencer

    Joined:
    Jul 25, 2010
    Re: Engine and Gearbox mounting plates for C'do engine in F'

    Duralumin , not al oom in um .

    Standard relationship for the Motor / Box , youd get a cardboard copy of the stock command cradle , or plywood , whatever .

    to go off at a tangent , throwing the motor down ' n fwd , and the gearbox rearward (chaincase has to clear at swing arm plate )
    and bludgeing butchered chaincases to cut'n'weld a longer one , could optimise weight distribution .

    If your cradles knackered you could whack the extremeties off , and throw the drivetrain in the frame .
    Get some matched offcuts of chipboard or matching somethings , and go for 1/4 in clearance under engine. thereabnouts.or maybe 1/2 .

    Note the front Iso comes into this , use also as pattern .

    throwing / glueing extensions of stuff to catch frame lugs .

    Then you remove , without knocking anything loose , after haveing chewed a bit of cardboard to establish practicality of head steady .
    THIS is ACTUALLY a Frame Brace ; it takes the longitudeinal brakeing and landing forces , amougst others . No tackey shit there .

    Once removed , you do some high faluteing paper copies . remembering to try to avoid sudden changes in shape / pofile , as stress raisers
    could be introduced . ( Notches , nicks , irregularities ) particularly if you intend to blow off the opposition on it . Or intend it to land stright
    at over 100 mph .


    A few pics , then the lecture on HOLES . :D

    ancient upright ; V. Good .

    [​IMG]

    shiney modern . looks a bit close together . as in you can see how much you could shift the Injun Fwd , & get G'box output in correct relationship to Swing Arm pin . :D

    [​IMG]

    Favourite Manx Commando ; engines in same position , by the looks , runs Commando Chaincase . 70s Big Bike mag. ?? artical , or similar mag. California machine. one assumes a rich boy . But I coulda bought a Manx Triton oily wreck for 600 or maybe even 300 , centuries ago. :cry: I realised recently . :x

    [​IMG]
     
  3. Matt Spencer

    Matt Spencer

    Joined:
    Jul 25, 2010
    Re: Engine and Gearbox mounting plates for C'do engine in F'

    Right ; ho fie lo egad & away . . . Of to the metal suppliers , or a alloy fabricateing shop , to bludge theyre offcuts . :) like a bull bar or boat , Aircraft
    outfit . etc. And if you havnt one , bludge the use off there largeish Drill Press . Without a DRILL PRESS , your not going to roast your turkey . :?

    these things ensure Straight Square holes . Bought 3/8 Silver steel for coustom Engine mount bolts . cut & tap threads. Turned out 10 mm . :oops:
    perfect fit with 10 mm bit through cases to line ream , and drift in . :oops: Used to be all the rage, Line Reamed Mounts . :mrgreen: :|

    ANYWAY . you need a EXCELLENT pointy centre punch . Mark the holes with 4H pencil , & square . a Dead CROSS . Exactly Positioned .( at least in case of the powertrain * )

    THEN ' we ' get a 3 / 32 bit ( and a few spares :oops: ) and crefully , at a medium speed , after youve centre punched the lot ( * ) Drill PILOT HOLES .
    if you stuff one up you can re centre ON the CROSS with a Needle File , oversize . :lol: we only allow a slight initial drilling UNTILL wee check its DEAD CENTRE

    Then Right Through .

    Ditto 1/4 Drill .

    Check Inspect ( nice clear plastic rule marked 32nds , & a good EYE )

    Then whack the 3/8 or 13 / 64ths drill though .

    +++++++++++++++++++++++++++++++++++++++++

    Cunning Sneak way is THEN to throw the *#^% in the frame , after haveing thrown steel rods through the cradle lugs ( and S/A mount ) and eyeballed em from afar for parralillity and trueness . A ruler ( 3 ft 0 can help here . as do 2 ft plus rods , for amplifying the effects.Wack timber wedges to set in location .
    fore / aft , or top / or down. Weight on while wee wedges wacked to lock )

    EGAD . so thats all cheched ( regarding as to if its been misstreated , in respect of violence & obsticales . :? )

    THEREFORE the dang CRADLE should sit in Square . We check this with straight edges , spirit levels , and / or bits of string . ( We have the Tecnology . :D :p :lol: 8) )

    ( * ) , now , ! being wxtreemmely cunning , :) we get our pencil , stick it through the LUG HOLES in the FRAME , and DRAW little Circles through the frame lug holes onto the ALLOY SHEET ( mounting plates , near finised now ) Getting the plastic ruler ( the clear 32nds one ) , if we dont wipe the pencil off with our thumbs , we locate the dead centre off the holes , and with them IN THE DRILL PRESS , drill the 3/32 pilot holes again THERE , where they fit THE FRAME .

    Now , We hold them up to the light. :D :shock: with a few bolts through . And SEE if the Pilot Holes Align .
    At this stage we have a beer . If theyre within 2 mm ( 3 / 32 in real money )we wack the 1/4 drill through
    or tru in america, while whistling , then the 3/8 or 13 / 64ths.
    then bevel edges with a largeish 45 deg. tipped bit .

    And belt the bleddy bolts in with a Nylon Mallet . :wink:

    Should I repeat anythin there . :mrgreen:
     
  4. ashman

    ashman

    Joined:
    Jul 11, 2010
    Re: Engine and Gearbox mounting plates for C'do engine in F'

    I have a spare set of engine plates for my 850 to featherbed frame if you like I could copy them to cardboard and send them to you with all the holes marked out, let me know if you want to go this way.

    Ashley
     
  5. Matt Spencer

    Matt Spencer

    Joined:
    Jul 25, 2010
    Re: Engine and Gearbox mounting plates for C'do engine in F'

    Spoilsport . :p :mrgreen:
     
  6. jaydee75

    jaydee75

    Joined:
    Jul 2, 2012
    Re: Engine and Gearbox mounting plates for C'do engine in F'

    I'm kinda new here, but from the above post I have to assume that Matt lives in Arkansas, somewhere near Hobot.
    JD75
     
  7. acotrel

    acotrel

    Joined:
    Jun 30, 2012
    Re: Engine and Gearbox mounting plates for C'do engine in F'

    I've made my own engine plates several times. All I do is sit the engine and gearbox in the frame and cut out cardboard templates then 8mm hard aluminium. There are only a few important things to know:
    Keep the engine in a fourstroke as far forward and low as possible. If it leans forward without the carbs hitting the tank, that is good. Keep the gearbox as far back as possible, allowing for adjustment , and the sprocket centre must be at least (about) 5mm below the line between the pivot, and the rear axle centres. I use a band saw to cut out the outside of the plates, and a jig saw to cut out where the gearbox goes (my plates are always 'full circle' ). Once you have got the shapes cut out of aluminium, use a bolt with a point on the end to mark the centres for the holding bolts, by clamping the plates to the engine. I usually drill one hole, and bolt the plates to the engine, then mark the rest and drill the tw o plates together. Don't forget to use drills slighly smaller than the hole size you want. The holes always come out bigger in aluminium, and if the holes are not tight you can get movement which can crack the plates. Reaming them to size is a good move.
    Making engine plates is a bit of work, but I always get a great sense of achievement out of it, especially when the bike handles really well due to the correct weight distribution. ENJOY !
     
  8. laurentdom

    laurentdom

    Joined:
    Nov 30, 2012
    Re: Engine and Gearbox mounting plates for C'do engine in F'

    Many thanks / Merci beaucoup to all of you.

    My technology skills are growing fast thanks to your comments (it's always like that when starting from zero or so ...).

    Thks for the offer Ashley. I'm going to send you a pm with my details.

    L.
     
  9. pommie john

    pommie john

    Joined:
    Nov 18, 2005
    Re: Engine and Gearbox mounting plates for C'do engine in F'

    If your featherbed frame has two mounting lugs on each of the front downtubes, like mine has, it's a bit of a game jiggling the front plates into place. My front mounting plates are 1/4 dural but they had to be milled a little thinner where they bolt onto the lower of the two front mounting lugs.




    [​IMG]
     
  10. laurentdom

    laurentdom

    Joined:
    Nov 30, 2012
    Re: Engine and Gearbox mounting plates for C'do engine in F'

    Hi Acotrel,

    When you say that the gearbox sprocket center must be at least 5 millimeters below the line between the pivot and the rear wheel spindle, you mean the swinging arm pivot isn't-it ?
     
  11. Matt Spencer

    Matt Spencer

    Joined:
    Jul 25, 2010
    Re: Engine and Gearbox mounting plates for C'do engine in F'


    Here , Actually .

    http://www.youtube.com/watch?v=-ok4iHt4Wvg
     
  12. pouchy750

    pouchy750

    Joined:
    Aug 20, 2010
    Re: Engine and Gearbox mounting plates for C'do engine in F'

    Do I see a 4 valve head on that gorgeous Commando Featherbed?

    I thought Norvil had given up on that a long time ago.

    Please tell us more about it, the performance increase, how you developed it, where you got it from.
     
  13. lcrken

    lcrken VIP MEMBER

    Joined:
    Mar 15, 2009
    Re: Engine and Gearbox mounting plates for C'do engine in F'

    Sharp eyes there. It does indeed look like it is fitted with the Piper designed 4-valve conversion, tried by Norton, later sold to Fair Spares/Norvil, and eventually sold to Andy Molnar (I think).

    There's a thread on it here somewhere, if you search for it.

    Ken
     
  14. Rohan

    Rohan

    Joined:
    Aug 26, 2010
    Re: Engine and Gearbox mounting plates for C'do engine in F'

    Set of engine plates for a Commando-in_Featherbed.
    These little puppies are steel, duplicated (thin) for the front plates, they'd need to be pretty thick in alloy to be strong enough. ?

    Tried these some years ago, they were not quite right somewhere, can't quite remember where or why.
    Think they lean the engine forward, but can't even quite remember that bit either...
    The black plates almost look like they are out of something, and have been used, but can't think what that might have been ??

    http://i1113.photobucket.com/albums/k50 ... 1356315605
     
  15. lcgtr

    lcgtr

    Joined:
    Sep 15, 2010
    Re: Engine and Gearbox mounting plates for C'do engine in F'

    Ever get hold of any scale drawings?
     
  16. Chris

    Chris VIP MEMBER

    Joined:
    Jan 21, 2008
    Re: Engine and Gearbox mounting plates for C'do engine in F'

    Hi

    I had the same problem with my front mounts as Pommie John & mine were milled to suit. Putting the gearbox sprocket center below the center line of the swinging arm pin/rear wheel spindle is supposed to help pull the tyre down onto the road.

    On my Rickman with the engine canted forward the studs for the alternator all had to be moved the inner chaincase chain boss removed.
    It gets a bit tight in the cases. I brought damaged ones to alter as I couldnt face butchering a set.

    Chris
     
  17. lcgtr

    lcgtr

    Joined:
    Sep 15, 2010
    Re: Engine and Gearbox mounting plates for C'do engine in F'

    Anybody got any drawings of the engine plates by any chance
    Im starting on my own this week
     
  18. ashman

    ashman

    Joined:
    Jul 11, 2010
    Re: Engine and Gearbox mounting plates for C'do engine in F'

    Wideline or Slimline, if Slimline does it have 1 or 2 front mounts as the wideline only has 1 front mount as I have a spare set of engine plates up in the shed and can send you drawings of them if you want, but have to be quick as I am going away for a few weeks after Wednesday.

    Ashley
     
  19. acotrel

    acotrel

    Joined:
    Jun 30, 2012
    Re: Engine and Gearbox mounting plates for C'do engine in F'

    It is a lot more fun making your own engine plates from scratch with cardboard and a jig saw. Often if you buy a set ready made, the motor is too far back. With the featherbed frame I recommend you move it as far forward as you can and keep the gearbox fairly well back. The centre of the gearbox sprocket only heeds to be slightly below the line between the centre of the swing arm pivot and the centre of the rear axle. When you are shaping the cardboard template, it pays to have the completely assembled motor and gear box chocked firmly into position in the frame. I usually make full circle engine plates that go right around the gearbox. If you make the LHS plate first then make the RHS identical, then you have enough material to cut it away a bit at the front of the RHS top where the gearbox touches.
    I usually muck around with the template for a bit until I get it right, then mark out with an ink pen on the aluminium. I usually end up holding down the aluminium on a bench with my foot while I cut it with a hand-held jig saw. 8mm hard plate is easy to cut with a jig saw. You need a good linisher belt to finish the job. I use a small drum sander in a pistol drill to finish the opening around the gearbox. When you are drilling the holes you need 3/8 inch rod with a sharp point on the end to slide through the mounting holes of the engine to mark the centres. Also remember to use an undersize drill when drilling aluminium to get the holes a snug fit.
    You should get a sense of achievement out of this exercise.
     
  20. lcgtr

    lcgtr

    Joined:
    Sep 15, 2010
    Re: Engine and Gearbox mounting plates for C'do engine in F'

    Thanks guys.
    650ss slimline, 2 sets of front tabs.
    I wanted to use commando primary and maintain commando engine tilt.

    Ive also heard a lot of conflicting info on wether ally or steel is a better way to go, what do you guys think and foes it actually make any difference to vibration
     

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