CB450 Tracker

[1fasgsxr]

Looking good.. perfect lines on the exhaust

 

[Pete12]

Looking good.. perfect lines on the exhaust

Thank you and thanks for following along.

As I am building a 2 into 1 system I need to make a collector to transition between the two. Bell's book suggests a collector taper of 7-8 degrees (not that it's going to be a race bike, but it may as well be done somewhere near right), so I developed the pattern in AutoCAD. Even though it takes time it's still a whole lot better than taking to the bare metal with the marking blue, divider, ruler and scriber, imho.
https://i.imgur.com/nYmTlhG.jpg[/IMG]]
Once that was done I isolated the pattern outline and converted it to a BMP file. I then imported that into my sticker cutter (another great toy that I was lucky enough to buy, without any possible hope of payback), and cut the pattern.
https://i.imgur.com/WAjT4bj.jpg[/IMG]]
I then stuck the pattern onto a bit of old body steel, and cut around it with the snips.
https://i.imgur.com/mWmgxWm.jpg[/IMG]]
https://i.imgur.com/BiZST2p.jpg[/IMG]]
I then welded the seam and rolled it up around a bit of pipe in the vice, and it fits pretty good.The steel I used is quite rusty so I'll get a new sheet next week as I still have the rest of the megaphone to manufacture.

 

[cxman]

what size is your main pipe and mandrel bends

 

[Pete12]

what size is your main pipe and mandrel bends

Pipe ID about 38mm.

 

[Pete12]

Can't do much until I get some body steel so I milled some slots in the two countershaft sprocket covers. I'll let my brother decide which one he wants to go with and he if he doesn't like either then new s/h covers are plentiful and cheap

 

[Pete12]

Finally got around to making the new collector and fitted it up. I also dressed all the welds on the joins and it came up OK.
https://i.imgur.com/JmEFoDx.jpg[/IMG]]

Cut some more body steel and welded and rolled up a 50mm tube for the next part of the exhaust.
https://i.imgur.com/YSGyLLn.jpg[/IMG]]
https://i.imgur.com/RCzhmfp.jpg[/IMG]]

I then cut and tacked some segments for the bends
https://i.imgur.com/QUSYjrT.jpg[/IMG]]

Once that was done I fitted the pipes and taped the joins together to ensure the fit was OK.
https://i.imgur.com/ZzvFJtC.jpg[/IMG]]

I will make the megaphone next, mock it all up and once I'm happy with the fit, weld it all together. When that's finished I'll make and install the baffle and then move on to the tank.

 

[JadusMotorcycleParts]

Looking awesome! That rolled collector came up amazing. Cool technique.

 

[Pete12]

Looking awesome! That rolled collector came up amazing. Cool technique.

Thanks very much for the positive feedback.

Printed up some sticker templates today for the megaphone and reverse cone so I should be able to get that done in the next couple of days. Even without the sticker maker it's very easy to draw the pattern for a cone directly onto the body steel, this just makes it a little easier and quicker
https://i.imgur.com/Z36deQr.jpg[/IMG]]

Also made a couple of stickers to be placed discreetly on the swing arm ;D ;D

 

[Pete12]

Put the stickers on the body steel and cut around them ready for rolling and welding.
https://i.imgur.com/6kLxzp3.jpg[/IMG]]
Before I get onto that I want to finish the headers so I finished welding the sections together, which are just fuse welded with the oxy/acetylene.
https://i.imgur.com/Ks3bHcw.jpg[/IMG]]
There is a bit of undercut but the penetration is really good and it just leaves a nice neat bead around the inside of the weld.
https://i.imgur.com/IuXewPe.jpg[/IMG]]
I've been building two stroke pipes for a long time now and never had one so much as crack, so it works for me.

 

[Luugo86]

Nice welds, I like using the oxy/fuel rig for stuff like this. I like where this project is heading.

 

[Pete12]

Nice welds, I like using the oxy/fuel rig for stuff like this. I like where this project is heading.

Thanks very much for the comment. I have tig which I use for most things but have always used the O/A set for pipes. Very easy to control and direct the weld puddle. Someday I'll make a little speed controlled chuck so I can get a continuous weld around the butt joins.

Rolled up the cones around a length of pipe in the vice and welded the seams.
https://i.imgur.com/YaWVSBo.jpg[/IMG]]

Welded the reverse cone onto the megaphone and then tacked it onto the pipe.
https://i.imgur.com/F7XbXWR.jpg[/IMG]]

It's only tacked at this stage as it is on the mock-up bike with the rear end on the actual bike a bit different. As the actual bike doesn't have a head on it at this stage I will wait until its final assembly stage to finish welding the pipe completely. I'll also run a second pass around the join between the megaphone and the reverse cone and dress it back for a seamless finish. I will wait to install the baffle until I can actually run the bike with different baffles to see which type performs (and sounds) the best.

The exhaust looks a little out of place on the mock-up bike but I think once it's all finished and painted it will look OK. Next project, the fuel tank...

 

[Aussie Steve]

This is really very interesting. If you ever feel the urge to post a video on YouTube about your exhaust making technique, I'd watch for sure. No doubt a lot could be learnt. Keep up the nice work.

Sent from my Lenovo A6020a40 using DO THE TON mobile app

 

[Pete12]

This is really very interesting. If you ever feel the urge to post a video on YouTube about your exhaust making technique, I'd watch for sure. No doubt a lot could be learnt. Keep up the nice work.

Thanks Steve. What are you interested in particularly? Megaphone design, pattern development, material selection, shape forming or welding? Not too sure about a YouTube video but happy to share some advice, for what it's worth.

 

[jag767]

That's very impressive. I'll be interested to see your process doing that as well.

 

[Pete12]

That's very impressive. I'll be interested to see your process doing that as well.

Thanks Jag, haven't seen anything from Steve yet so not really sure what you want to see. No problem with any of it, I just don't want to tell you things you already know...

Sat the head on the good bike today to see how the exhaust fitted up and it clashes with the rear caliper hydraulic hose - good thing I only tacked it together.
https://i.imgur.com/ScPYIHc.jpg[/IMG]]

Also put the seat on off my race bike so that I can get started on building the tank. The seat has to come down about 25mm which will happen when I make up the new rear loop. This will put the seat height at just over 800mm from the ground, which should be a good height. I'm going to buy a seat, as the Knight shape is quite complex and not so easy to make from scratch out of aluminium, and they are not expensive.
https://i.imgur.com/wpJxgA9.jpg[/IMG]]

I also took the rear right hand cam bearing off my spare head and put it on the front right hand side of the new motor so I don't have that ugly obsolete tacho drive sitting there.
https://i.imgur.com/CJIVwx7.jpg[/IMG]]

Getting closer now, I'll be happy once I've got the tank made and positioned correctly. I can then make the seat loop, battery tray and front mudguard.

 

[Pete12]

I bought some cardboard to get started on the tank template but before I started I sat the old tank on to see how it would go lengthwise with regards to the seat position. Funnily enough, the original didn't look too bad on there...
https://i.imgur.com/LVshn1Z.jpg[/IMG]]

It looked a little too wide so I decided to narrow it up by 25mm. Firstly, I cut the filler cap out with a holesaw.
https://i.imgur.com/28K3El0.jpg[/IMG]]

I then cut a 25mm strip out of the centre and then cut the flanges off all the way around, so the tank is now in four pieces.
https://i.imgur.com/bDjf6jK.jpg[/IMG]]

The next thing will be to knock all the dents out, (and there are many of them ), then make a new tunnel and weld it all back together again. Once that's done I can make the new rear loop then align the tank and seat properly before finalising the tank mounts.
I taped the tank back together and these are before and after photos.
https://i.imgur.com/808Fw6J.jpg[/IMG]]
https://i.imgur.com/iTFH82L.jpg[/IMG]]

I sort of like the idea of using the original tank as it will retain some of the bike's character. If it doesn't look good when it's all fitted up then I will just revert to plan A, and make a new tank.

 

[SONICJK]

I like it.
I think I'd take it down another inch or so in width and it will be killer.

 

[Luugo86]

I like it.
I think I'd take it down another inch or so in width and it will be killer.

+1
Also, is the tailpiece a unit that you ordered up or fabricated? I like it.

 

[Pete12]

+1
Also, is the tailpiece a unit that you ordered up or fabricated? I like it.

I like it.
I think I'd take it down another inch or so in width and it will be killer.

Thanks for the feedback guys. I can't really narrow it any more at the back as it is now the correct width for the seat, which is important in my opinion. I'm also struggling to get the fuel tap in to clear the carbs, but I should be able to find a way around that. I will, however, narrow it up more at the front which I believe will still have the desired effect. I'll finish knocking all the dents out then tack it together and see how it looks.

Luugo86 - the seat is a Knight type off my race bike and I'm just using it for the mock-up but will be getting one the same for this bike. Depending on where you live you can buy them in England or the States, possibly Europe as well.

 

[Pete12]

I ended up cutting nearly 40mm out of the tank and I think it looks OK. I tried overlapping it a bit more to see how it looked but it was starting to get a little skinny for the height so I've gone with what I had. I knocked all the dents out and then welded the seam together and will make the tunnel next and then weld that in. I can then position it correctly and make the front and rear mounts. It's certainly recognisable as a CB450 tank, just looks like it has been on a diet, which is pretty much the look I was aiming for. It matches the seat where they meet, so once the two are lined up correctly height wise they should both look like they are meant to be there. We haven't decided on a colour yet, but my brother is pretty keen to use the original striping design, carried through to the seat tail. Sounds OK to me..

https://i.imgur.com/OQ5Z8tw.jpg[/IMG]]

I'm undecided at this stage whether to buy a pop-up cap or just make a regular screw-on cap, but no hurry with that at this stage.

The manifold that was supplied with the new Mikuni carbs is a universal type and doesn't match up to the head too well,

https://i.imgur.com/3u7hqUq.jpg[/IMG]]

so I milled up a transition piece that matches both sides.

https://i.imgur.com/OxkWEaM.jpg[/IMG]]
https://i.imgur.com/MzNko8n.jpg[/IMG]]

I think it looks better aesthetically, and it will also give fuel tap a little more clearance, so I'm pretty happy with that. The increased inlet tract length may even give it a bit more low down torque which will be a good result if that is the case.