Page 2 of 5 FirstFirst 12345 LastLast
Results 16 to 30 of 64
  1. #16
    Join Date
    Mar 2009
    Location
    Melbourne
    Age
    54
    Posts
    825

    Default

    Quote Originally Posted by gazza2009au View Post
    Hey Greg this is a 4 stroke cylinder no ports just a strait sleeve
    My mistake, probably should have looked at your photos more closely.
    All the YZ's run by mates I used to ride with were two strokes, mind you that was the late eighties through the nineties so things have obviously changed since then.
    Now I think about it, Honda changed their CR to a four to meet emissions compliance so I guess it makes sense that Yamaha did the same.
    Can you get a two stroke dirt bike these days?

  2. #17
    Join Date
    Aug 2009
    Location
    Sydney, NSW, Australia
    Posts
    1,836

    Default

    Yeah 2 strokes are making there way back they were ditched by a couple manufacturers think honda and possibly suzuki ditched them in the lster 00 era ktm, yamaha, husqvarna are still doing 2 strokes

    The older 2 strokes seem to be realy popular these days, the "F" in the model stands for 4 stroke YZ250F, CRF250 etc.. guys are putting the mid 1980's CR500 engines which are 500cc of pure 2 stroke addrenalin it to modern road registable 4 stroke 450cc 4 stroke frames and the authorities havent caught on yet

  3. #18
    Join Date
    Aug 2009
    Location
    Sydney, NSW, Australia
    Posts
    1,836

    Default

    Hey guys heres a question can u make your own sleeves? Do sleeves have to be any specially kind of treated steel or something?

  4. #19
    Join Date
    Aug 2011
    Location
    Perth, Western Australia
    Age
    67
    Posts
    362

    Default

    Cast iron was the go 30 years ago.
    Sleeve in the freezer for 24 hrs (or liquid nitrogen if you can get it now). Barrel in the oven to about 220 deg C. Slip it all together and don`t stuff up or it gets real messy. Hone bore to size.
    All machining to less than .001" runout.

    Not saying it cannot be done on your lathe, (never used one that small and I am no machinist) but......

    Tony

  5. #20
    Join Date
    Aug 2009
    Location
    Sydney, NSW, Australia
    Posts
    1,836

    Default

    Actually im going to send a email to the sleeve manufacturer and ask for all the dimentions than try machine my cylinder if it works out and the lathe machines the bore correctly i'll order the sleeve

  6. #21
    Join Date
    Aug 2009
    Location
    Sydney, NSW, Australia
    Posts
    1,836

    Default

    Tony yeah its still done that way L.A Sleeves has all the sleeve information on there web site, cylinder needs to be machined .004" or .012mm smaller than the sleeve or possibly bigger i will confirm this

    Sleeve than gets honed to the correct size for the piston

    Sleeves come in 1.5, 2.3 and 3mm thicknesses 2.3mm wall thickness being the majority

  7. #22
    Join Date
    Oct 2004
    Location
    Southern Highlands NSW
    Posts
    1,894

    Default

    Repairers of early motorbikes have used cast iron water pipes to make sleeves, after turning out the concrete lining.
    Used removable sleeves from diesel truck or tractor engines etc could possibly be a source, if thick enough where it's needed.

  8. #23
    Join Date
    Mar 2011
    Location
    Southern Flinders Ranges
    Posts
    1,536

    Default

    Not sure a 3jaw in a lathe would be my weapon of choice for this job

  9. #24
    Join Date
    Aug 2009
    Location
    Sydney, NSW, Australia
    Posts
    1,836

    Default

    Thanks Nad and Racing

    I will buy a proper cast sleeve, looked into how to approach this idea last night and found my self on practical machinist i read a lathe is next best thing for boring cylinders

    They were saying i need two plates one either end of the cylinder these are called torque plates than i need to bolt the plates to the carriage and make sure the cylinder is absolutely center to the chuck than run a boring bar from the chuck to the dead center

  10. #25
    Join Date
    Aug 2009
    Location
    Sydney, NSW, Australia
    Posts
    1,836

    Default

    Decided to take the approach of using my mill attachment i plan on picking up a 25mm thick adaptor plate tomorrow to go between the mill attachment and the job a plate to bolt both together with

    My bore is 77mm the new sleeve is 2.34mm thick wall since i dont have the sleeve yet i will set it all up and just skim the wall for now to check its true cutting the ehole cylinder wall evenly

    Overall cylinder boring needs to come.out from 77mm to roughly 81.6mm not being exact as the sleeves vary from each other

    But this should give me an indication if my home boring will work, if it fails the cylinder is trash at the moment anyway

    Any idea on best way to center the job?

  11. #26
    Join Date
    Jun 2007
    Location
    sydney ( st marys )
    Age
    64
    Posts
    4,887

    Default

    You would probably be best to use a dial indicator, you will need to also get the face of the cylinder square horizontally and vertically.
    Maybe you should set out your machining method step by step here first.

  12. #27
    Join Date
    Aug 2009
    Location
    Sydney, NSW, Australia
    Posts
    1,836

    Default

    Hey Pipe i was hopping to rely on the mill attachments face to be square ( the yellow L shape bracket)

    Any idea on how to set up the dial indicator?

  13. #28
    Join Date
    Aug 2009
    Location
    Sydney, NSW, Australia
    Posts
    1,836

    Question

    This is how i was setting it up there will be a custom aluminium plate/adaptor between the cylinder and the yellow L milling attachment it will all be bolted together

    Plan was to make a steel boring bar but the boring bar holder will be made so it slides inside my chucks hollow shaft as the shaft comes out into the chuck jaws it will be 50mm with an adjustable tool

    The boring bar holder will be like 100mm of 16mm dia that slides inside the chucks shaft than it will be 50mm dia right out enough to bore the cylinder planned on doing it this way so the extra shaft inside the chucks shaft should ensure the boring bar does pull out of the chucks jaws and screw the job
    Attached Images Attached Images

  14. #29
    Join Date
    Aug 2009
    Location
    Sydney, NSW, Australia
    Posts
    1,836

    Default

    Not sure how you guys would have made a 80mm+ size hole in 25mm plate but i drilled lots of holes than worked out i was undersize so now lots and lot of die grinding

    Noticed i lost a good 40% of power on my new ryobi die grinder not sure what happen there that thing was a power house not its only ok

    Hole in the aluminium still needs to come out about 3mm i was under by about 6-7mm

    Will continue tomorrow and hopefully get it mounted to the lathe

    So far im in it $22 for the plate and a bummed cylinder so its not a big investment.if it dont work out
    Attached Images Attached Images

  15. #30
    Join Date
    Jun 2007
    Location
    sydney ( st marys )
    Age
    64
    Posts
    4,887

    Default

    You will need to make sure that the angle bracket is square to the spindle.

    Can the bracket be adjusted in and out by the cross slide or compound once locked down?

    You will need to have some type of vertical adjustment for centring barrel when using the dial indicator, at this time the barrel should be locked up hard against your angle plate.

    You can just mount the dial indicator in your chuck for setting up.

    You will also need to use the dial indicator for adjusting your cutting tool.

    You may even want to consider using a boring head in your lathe spindle directly rather than making a boring bar.

Page 2 of 5 FirstFirst 12345 LastLast

Similar Threads

  1. Opening a used LPG Cylinder
    By Grahame Collins in forum WELDING
    Replies: 8
    Last Post: 21st Nov 2019, 11:24 PM
  2. Hydraulic Cylinder Fix
    By RustyArc in forum METALWORK GENERAL
    Replies: 11
    Last Post: 2nd Dec 2018, 09:22 AM
  3. Hot Cylinder on Two Stroke
    By Goggomobile in forum AUTO RESTORATION
    Replies: 13
    Last Post: 17th Sep 2016, 01:46 PM
  4. cylinder hone
    By leroy in forum METALWORK GENERAL
    Replies: 8
    Last Post: 16th Mar 2014, 02:33 PM
  5. mig gas cylinder volume ?
    By barn in forum METALWORK GENERAL
    Replies: 31
    Last Post: 18th Aug 2007, 06:07 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •