Honda 650 single build - Page 2
Close

Honda 650 single build

This is a discussion on Honda 650 single build within the Project Builds forums, part of the Caferacer.net Forums category; Its just plain MiG welded mild steel tubing except I use 304 grade stainless wire. Not totally sure its really necessary but it welds nicely ...

Page 2 of 10 FirstFirst 1234 ... LastLast
Results 11 to 20 of 97
Like Tree50Likes

Thread: Honda 650 single build

  1. #11
    Senior Member unclerob's Avatar
    Join Date
    Jun 2015
    Location
    Kent, UK
    Posts
    198
    Its just plain MiG welded mild steel tubing except I use 304 grade stainless wire. Not totally sure its really necessary but it welds nicely and I'm told its more resistant to fatigue cracking than mild steel wire....that could well be an old wives tale though!

  2. #12
    Senior Member nic579's Avatar
    Join Date
    May 2010
    Posts
    2,150
    Quote Originally Posted by unclerob View Post
    Thats interesting....tuning info on these motors is a bit thin on the ground in the UK....thinking that the amount of trouble he's gone to with the oil system is for a good reason!
    Got the fairing made today but still in the mould and halfway done with the tank....making it from 20g steel as whenever I try to make an ali one I cock it up....
    I suspect he is giving it more crankcase breathing and that that unit is also an oil cooler. I will look and see what else I have on it but fear I lost the bulk of data in an HD crash.


    Actually I was just thinking that you have a great resource for the engines on ADV rider. http://advrider.com/index.php?thread...ign-in.114834/ Guys on here are willing to be very helpful and some do extensive performance mods.

    Also XR's Only in Southern CA http://www.xrsonly.com/

    From what I have heard is that these engines can be built up to the point where the cases are the weak point and fail.
    Last edited by nic579; 05-11-2016 at 05:28 PM.

  3. #13
    Senior Member TrialsRider's Avatar
    Join Date
    Jan 2011
    Location
    Ontario, Canada
    Posts
    3,877
    Quote Originally Posted by unclerob View Post
    Its just plain MiG welded mild steel tubing except I use 304 grade stainless wire. Not totally sure its really necessary but it welds nicely and I'm told its more resistant to fatigue cracking than mild steel wire....that could well be an old wives tale though!
    That explains the appearance of the welds.
    304 stainless almost certainly contains some chromium and nickel, the nickel properties would indeed make it far more resistant to fatigue cracking in the weld material relative to mild steel wire.

    Good stuff.

  4. Remove Advertisements
    CafeRacer.net
    Advertisements
     

  5. #14
    Senior Member hillsy's Avatar
    Join Date
    Oct 2008
    Location
    Brisbane, QLD, Australia.
    Posts
    5,863
    I've been told the key to getting good welds with DOM tubing is to heat up the area before you weld with a propane torch until the steel turns blue. Apparently this really helps the weld penetration and is particularly useful in frame building.

    I got that tip from a registered chopper frame builder in Oz, so I'd say he knows what he's doing. He also just MIG welded his frames.

  6. #15
    jcw
    jcw is offline
    Senior Member jcw's Avatar
    Join Date
    Jul 2015
    Location
    chicago burbs
    Posts
    831
    Quote Originally Posted by TrialsRider View Post
    That explains the appearance of the welds.
    304 stainless almost certainly contains some chromium and nickel, the nickel properties would indeed make it far more resistant to fatigue cracking in the weld material relative to mild steel wire.

    Good stuff.
    IN GENERAL, it is NOT a good idea to weld mild steel with stainless. Why? Don't ask me but the experts claim that when the stainless is diluted with the mild steel in the weld puddle, the amount of ferrite in the weld deposit drops below a critical value and MAY cause hot cracking of the weld. You might not see it but a small even micro crack can be a starting point for a big crack.

    Also, the usual ER70S-2 rod for mild steel has much more "cleaning" action due to the precense of elements that stabilize the weld puddle.


    Yes, maybe the ductility of stainless is better, but use too little filler, or weld too deep into the mild steel or use a stainless filler with a lower ferrite number, and you could be in for problems. Particularly in a motorcycle chassis.


    I will look for the references for the above.

  7. #16
    jcw
    jcw is offline
    Senior Member jcw's Avatar
    Join Date
    Jul 2015
    Location
    chicago burbs
    Posts
    831
    Preheating DOM tubing might help in thicker section and with CroMoly, where the preheat prevents too rapid cooling and subsequent cracking of the weld.

    I've never heard of mild steel tubing needing it.

  8. #17
    jcw
    jcw is offline
    Senior Member jcw's Avatar
    Join Date
    Jul 2015
    Location
    chicago burbs
    Posts
    831
    Quote Originally Posted by jcw View Post
    IN GENERAL, it is NOT a good idea to weld mild steel with stainless. Why? Don't ask me but the experts claim that when the stainless is diluted with the mild steel in the weld puddle, the amount of ferrite in the weld deposit drops below a critical value and MAY cause hot cracking of the weld. You might not see it but a small even micro crack can be a starting point for a big crack.

    Also, the usual ER70S-2 rod for mild steel has much more "cleaning" action due to the precense of elements that stabilize the weld puddle.


    Yes, maybe the ductility of stainless is better, but use too little filler, or weld too deep into the mild steel or use a stainless filler with a lower ferrite number, and you could be in for problems. Particularly in a motorcycle chassis.


    I will look for the references for the above.
    How to Tig Weld Carbon Steel

    Here's a great video of a great guy that puts out these great tig welding videos.

    He gives examples where using stainless on mild steel would be advantageous but with the caveat,

    There is some risk of hot cracking when stainless tig rod is used for carbon steel. But in my experience, that most often happens in full penetration butt welds...or highly restrained welds.

  9. #18
    Senior Member hillsy's Avatar
    Join Date
    Oct 2008
    Location
    Brisbane, QLD, Australia.
    Posts
    5,863
    Quote Originally Posted by jcw View Post
    Preheating DOM tubing might help in thicker section and with CroMoly, where the preheat prevents too rapid cooling and subsequent cracking of the weld.

    I've never heard of mild steel tubing needing it.
    Well, the other thing he told was to ALWAYS use DOM. Not CroMoly.

    Mind you, he was building hardtail frames so it's probably a bit different.

  10. #19
    Senior Member unclerob's Avatar
    Join Date
    Jun 2015
    Location
    Kent, UK
    Posts
    198
    Thats all I've ever done before as far as bike frames go too....made some chopper frames about 30 years ago! Its all MiG rather than TiG welded as I injured my left hand quite badly a couple of years ago and though it works ok now I don't have much feeling in my thumb so TiG welds look awful nowadays!
    Using stainless wire was something I learnt when making wishbones for Lotus 7 type kitcars so seemed worth doing here too...
    As far as the motor goes again I don't have much experience but always thought Honda singles tended to be more fragile at the top end rather than the bottom, I'll definitely give it an oil cooler and theres plenty of space at least for a nice big oil tank! I've been riding a stock one the last few days and get the impression there is potential for say maybe another 8 or 10 hp.....it feels very soft....tiny exhaust pipes, massive pair of silencers and a cv carb cocked off at an angle, also some weird air recirculation system. Hoping the flatslide carb I have and a bigger bore exhaust will make an improvement though I'm thinking some changes to the cam would be worth a go....have been talking to a local firm who are going to have a go at grinding me a couple of experimental ones.....
    Newman Cams - Performance Camshafts
    And having the head looked at here....
    Cylinder Head Shop | Race-tuning, re-engineering & development of motorcycle, car, boat and other cylinder heads; including valve design & manifold re-engineering
    Thanks for the links btw....there seems to be very little about them here in the UK....

  11. #20
    Senior Member hillsy's Avatar
    Join Date
    Oct 2008
    Location
    Brisbane, QLD, Australia.
    Posts
    5,863
    Not sure if that motor is one of them, but some of the early 80s Honda big singles had a tendency to wear out the camchain guides and subsequently saw a hole in the cylinder block opening up the motor to the outside world.

    Friend of mine had this happen on an XL500 and I've heard it from other people as well.

    Something to look into anyway.

Page 2 of 10 FirstFirst 1234 ... LastLast

Sponsored Links

Posting Permissions

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

Similar Threads

  1. FAQ: Honda single piston brakes
    By JD in forum Technical FAQ's
    Replies: 1
    Last Post: 12-08-2011, 07:04 AM
  2. Ducati 250 single build thread
    By tonupoakland in forum Project Builds
    Replies: 45
    Last Post: 05-07-2010, 12:30 PM
  3. Biggest Honda single??
    By bryanderr in forum General
    Replies: 6
    Last Post: 07-16-2008, 02:04 PM
  4. FAQ: Honda single piston brakes
    By kenessex in forum Technical
    Replies: 1
    Last Post: 06-11-2007, 06:14 PM
  5. basic performance parts for honda single...
    By jaguar in forum Vintage Motorcycle Racing
    Replies: 9
    Last Post: 11-16-2006, 11:48 PM