'72 CB350 K4 - 'ol no.7 - Swingarm progress

I guess we'll see how it goes. I got the stock from McMaster Carr which is where I'm getting my numbers from. They give it a "Good" on their machinability scale (below Excelent and Very Good) and a Maximum Attainable Hardness of C60-62. Still working on my metals knowledge so we'll see... I think I'll use the University's tap and die set for this one....

Thanks for the info, it helps a ton, I'm looking forward to seeing your solution too!

bob.
 
Yea, just be aware that it comes unhardened when you buy it, so you will need to harden it to get it up to those numbers. Which means you need to heat the metal to something like 1200 *F (consistently, not just with a torch), hold it there for a little bit, then quench it in a vat of oil. If it were to come hardened when you bought it, then you wouldn't be able to scratch it. So just something to keep in mind, you will need to have it hardened afterwards. I would not want to do it myself. Maybe the MSE department at your school could help you with that if you don't want to spend lots of money to have it done.

What University are you at/ what are you studying? I just graduated...(haha I keep saying that, but it has almost been a year! May '10) from Arizona with my BS Mech Eng.
 
Cool, thanks for the info, I'll start looking around.

I graduated from Philadelphia University with a BS in Industrial Design in 2007. In 2009-10 I worked there as a professor and taught the ID fabrication class. So now being an alumni and previous instructor I can pretty much show up there anytime and use the shop, pretty sweet deal.

bob.
 
Bobdot said:
Cool, thanks for the info, I'll start looking around.

I graduated from Philadelphia University with a BS in Industrial Design in 2007. In 2009-10 I worked there as a professor and taught the ID fabrication class. So now being an alumni and previous instructor I can pretty much show up there anytime and use the shop, pretty sweet deal.

bob.
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Nice! I have the same access too, I worked in the machine shop as a student for 3 years and helped teach the shop class, so I still have keys to that :)

But yea, see if you can find a heat treating place near you that will do it for cheap.
 
Thanks Danish, it's getting there. Got the steel for the bracing the other day so just gotta find some time to get to the shop to bed, cut, and weld it.

In the meantime I've been getting a lot of progress made tearing down the motor and sending bits out, but in the spirit of keeping the thread somewhat organized, I'll save the documentation for after the swingarm is done. Things are rolling right along! She won't disappoint!!

bob.
 
Alright, finally took advantage of a day off and locked myself in the shop for a few hours. Swinarm is getting close to done, about 95% all tacked up and ready for final welding. Here's the progress...

Filled the 5/8" OD tube with sand and tacked caps on each end. Jerry-rigged the stone-age pipe bender and made my hoop
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Used a 5/8" mill bit to match the supports on the tubing and a 1 1/4" hole saw rigged on the lathe to match up with the stock swinger at an angle of 20deg.
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Placed for fitment and tacked up
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Only made one swingarm spool brace before running out of steam, should have the other made up sometime this week. Here's where I left off:
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I should have some more time in the shop Friday and/or the weekend to get it all welded up. Just wondering if I should take the extra time to weld up a jig... we'll see. In other news, various engine parts are in various places and should start coming back to me starting late this week, hopefully its not another month before I post more progress on this beast.

bob.
 
So..., it has almost been another month. Where are we at on this beast? Any updates? I'm hurtin' over here...
 
Yea, it pains me to let it go by day after day but money has been tight and the new job has been super busy. Luckily there is light at the end of the tunnel and I have been able to plug along a bit on the engine build. Swingarm is welded up, just need to smooth it out and paint.

Here's where we stand with the ol' ticker:

Broken down
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Hard to believe it ran as good as it did with these things in it
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Ok, so onto the good stuff. Plan is to over-bore 1.5mm, '69 cam and rockers sent out to Delta Camshaft in Washington state for an aggressive street grind, port and clean the head, and cast my own custom rubber carb boots to match the Mikuni TM's to the new port. Icing on the cake will be a new electronic ignition from Pamco. I've head really good things about these untis on other bikes, just waiting for the dude to finish production for the 350's - info here: http://www.cb750ignition.com/CB450.htm OH, look at that, he's done! Yea, thems gettin ordered this week...

Accomplished so far:

Fresh bore and hone from Bore-Tech with new 1.5mm over pistons
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Cleaned valves waiting to meet up with there new kibblewhite bronze valve guides
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'69 cam and rockers from the ever so awesome Mr. Yinzer cut and re-faced by the good people at Delta Cam. $85 for a "Street Grind" and refaced rockers beats the hell out of a new $400 MegaCycle cam
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Still waiting to find an oven so I can slip the new valve guides in and then ship it off for a port and flow. Also gottafigure something out for cam rollers... buy OEM? Lathe new ones from Delrin? Opinions? Here's what I'm workign with:
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slowly but surely fellas, slowly but surely...

bob.
 
Those pistons make me drool Bob. Gotta be honest about it.....

I talked to Les Barker before about the 350 tensioner. It was a while ago and it just came up in the conversation so I can't remember the details, but there are other options. I'm sure somebody else will chime in with a better answer.
 
Yea Rich, they really are beautiful pieces, I'll try to get another close up shot of the whole piston out of the jug. The old pistons nearly fit inside the new ones yet the over sized still weigh in lighter, mainly due to a shorter overall stature and deeper cut valve pockets.
 
Bobdot said:
Icing on the cake will be a new electronic ignition from Pamco. I've head really good things about these untis on other bikes, just waiting for the dude to finish production for the 350's - info here: http://www.cb750ignition.com/CB450.htm OH, look at that, he's done! Yea, thems gettin ordered this week...
Click to expand...
i was pretty excited about this... haven't heard a good review of newtronics, hondaman seems good but not a complete solution and bore-tech is just stupid expensive... so a new cb350 electronic ignition playa seemed good! that said, bob, do you have something different going on with your bike that will accept a 450 ignition? i emailed pamco monday and he said he doesn't yet have a 350 ignition. here's his emailed response to me:

The points plate, which my system replaces, is different between the CB450 and CB350, so the model that we just made available will not work with your CB350.
We will be making a CB350 version soon.
Pete

i said he might get a bunch of business if he made a 350 version from this site... he said he signed up here as pamcopete so if we pm him with requests maybe it'll speed up development!
 
Bobdot said:
Rich, I shot Les Barker an email, hopefully it digs up something usefull. Thanks for the info.
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Fyi- sometimes Les doesn't check his email for a while. He is just a busy dude who wants to work in the shop, not talk on the phone or check emails. Know what I mean? So don't be surprised if it takes a long time to get a response.
 
I just read this entire thing front to back. Awesome ideas and execution all the way through. Your skills and garage appear to have both improved greatly.
 
Overdraft - yea I've been talking to him back and forth for months about this. Pretty much the only difference is the backing plate so hopefully he can get something figured out soon. I'm up for anything to help speed up the proccess. If not, I might just buy the electronics and machine a plate myself.

Rich - I've heard not so great things about using the KA slipper on street engines. I contacted Ohio cafe about those steel rollers months ago and never heard back so who knows.

Indie - thanks dude, definitely glad to be out of the living room/attic/ back porch phase.
 
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