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Maduncle's building a race bike

Discussion in 'Modifications and Projects' at netrider.net.au started by maduncle, Jan 23, 2014.

  1. Yep,

    After pressure from my peers to start a thread on my current project - here it is.

    I am building a Honda CB450 race bike, known as the CR450 back in the day, first raced by Bob Hansen in America in the late 60's.

    It will start as a track bike.

    Once I am competent at going round and round and round fastish - I will compete in historic racing in the P4 category.

    So I bought a CB450K3 engine because I wanted four cam followers and it was cheaper to buy a whole engine locally than to buy four cam followers in Americaland and get them posted to me.

    Then once I pulled the engine down, I decided this engine was in such good condition that I could rebuild it for my Black Bomber.


    I needed a new CB450 engine stand - so I went to the hardware store


    and bought aluminium square tube and plastic connectors. An hour later and I had an engine stand.
    • Like Like x 2
  2. Then I rode to Adelaide and back at Christmas time.

    On the way back I went to Mac Park near Mt.Gambier to watch some friends race their historic bikes - and the bug bit.

    So I went out and bought a CB450 frame, swing arm and a pair of wheels, so I could build a track bike using the engine I am building

    frame. .

    If I want the bike to be a historic race bike - my frame will need extra down tubes welded in and the centre tube removed, to look like this.


    And I have been busy on eBay, I got a pair of new 74mm pistons (takes the bike out to 498cc) CB500T front forks (so I can run single or dual front disc brakes) and I scored a good set of 'Hooker' brand headers and muffler for the race bike.


    Engine specifications (so far).

    498cc engine - 74mm pistons (up from 70mm).
    Megacycle mild grind cams.
    Cappellini needle roller bearing cam bearing inserts.
    New stainless steel high flow valves, new bronze valve inserts.
    Ported and polished head.
    Raised compression (to burn race fuel).
    Mikuni VM34 carbs and velocity stacks.
    Magneto electrics.

    Stock crank for a start, later on I can get real serious and fit a full pork chopped, polished and balanced crank if I need to.

    Nice pistons.

  3. japan_cr450. End of the day (or in a years time) I hope to have something that looks like this.
    • Like Like x 1
  4. Fantastic.

    Good luck with the build.
  5. This is going to be another great Maduncle thread.
  6. Not another CB450, Cliff? C'mon, couldn't you have come up with something more creative this time? ;-) :p

    Seriously though - it looks good! Can't wait to hear what comes next...
  7. Cliff, you can only be described as amazing! A "Must Follow" thread.
  8. So about those nice pistons...

    If I run the 74mm pistons, I will have a 498cc bike but I will also have 1.5mm steel skirts and be riding a 498cc hand grenade.

    So I now have a pair of 74mm bookends and I am searching for a pair of 73mm pistons, which will give me a 484cc race bike and good solid 2mm thick skirts.
  9. Steel skirts, sounds hot @Uncle Greg, you need to check this out :)
  10. Aaaaand we're back.

    So I am back to using the 74mm pistons again - they became 'unsold' when my clever engineer decided he could bore out the barrels (isn't that a song?) by and extra 1mm diameter and fit big bore sleeves, 78mm OD x 74mm ID, giving me 2mm sleeve wall thickness.


    And today I collected all my pretty engine pieces from Woody's Hydroblasting in Sandringham.

  11. I love Shiny Objects. ;)
  12. Oooh, purdy.

    Random thought - did anyone else look at that little race bike above and see a skyteam ace with a fairing? Could be a cheap source for a tank...
  13. Way ahead of you there.

    Spoke to the importers already - around $200 for a tank.
  14. Now that's interesting. You didn't price a seat unit while you were there did you?
  15. From the supplier:

    For a tank + seat we would charge $220 + $50 post + packing.

    The tank comes with the rubber strap and the seat comes with the fixing brackets.
    Ikonik Motorcycle Company
    U7 / 9 Inspiration Drive Wangara WA 6065 Tel : 08 9302 6322 Fax : 08 9302 6355
  16. Cliff, I love the passionately organised way you go about your projects, I hope I can do half as neatly when (if) I can get my new garage cleared and a project of some sort started....
  17. Messy is not an option for me Paul - my workspace is a 1.4m x 2.7m store room, everything is stacked to the ceiling, even hung on hooks from the ceiling. Not sure how I am going to work on the frame yet.

    Anyone in the Coburg Victoria got a garage/workshop space to rent?
  18. Airtech have nice stuff, it's just a shame you have to use a freight forwarder. I'm sure you're all over it, but if anyone else is interested they don't ship to Australia. They will ship to third party shipping agents, and will recommend a couple if you enquire.