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

no word from Les yet but I did order a new rubber large cam roller today from work, which to the suprise of the parts dept. was not only in the fische but available direct from Honda. Booyah. The whole assembly was actually available but kinda pricey so I'm still pondering over the small roller which from what I read takes the brunt of the stress. Wondering now if its worth buying a new heavy duty cam chain or sticking with the perfectly healthy stocker... In any case, this puppy should start to take shape again within a couple of weeks.

Then I get to play around with jets.

bob.
 
"Also gottafigure something out for cam rollers... buy OEM? Lathe new ones from Delrin? Opinions?"

Uh, turn new ones from delrin? Why are we thinking about this Bob?
 
Say Mr. Bobdot, anything new? ;)

Btw, where did you get the materials for the swingarm pivot bolt? I found some amazing bronze bushing with needle bearings on ebay, but if I can't get a hardened bolt I might as well buy the normal bronze bushings.

Rune
 
If I recall correctly I think he got it from McMaster-Carr. We still have to machine and harden it, so that's still in the works.
 
How do you go about doing that then? Heat it up, cool it down, heat it up, cool it down? I would love to see some of the process :)

Rune
 
The hardening goes like this, using a piece of high carbon steel (must have higher than a certain percentage of carbon or it will not harden) after machining you heat it up until its a little above cherry colored, this is in the 1400 F range, it will lose it's magnetic property. Then you perform the quench, which is rapidly cooling the hot metal in a liquid, this liquid depends on the type of steel (W2 needs water, O1 needs oil, A2 D2 and a lot of special tool steels use air and some crazy setups). Assuming the quench was competed fast enough, the steel is at it's maximum hardness, it is also really brittle at this stage and would be prone to shattering. You then temper by heating it in an oven for a certain duration at a certain temperature. This all varies with the type of steel and final hardness needed. In the case of this axle the hardness should be at least RC 59, a value on a specific scale. We'll chose a tempering regimen that will shoot for 60-62.

The hardest part of the whole thing on a piece like this is quenching without warping the axle, you run into similar problems with swords and other high length : cross section ratios. I'm confident though.
 
Well put Walsh, theres a few places around philly that might be able to help out on that front. Maybe I'll set a goal to get that axle machined and ready for hardening this week.

However, other progress is at a snails pace, as I am broke...

Rune, I know the bushings you are talking about on ebay, thats where I got the idea for mine from. It just doesnt make sense to use Bronze AND needle bearings since bronze is used as the stock component for its wear resistance. I'm really just going the needle bearing route for the sheer fun and challenge of it, its a ton of extra work. If you're just looking for a solid, proven, and hassle free solution I'd stick with the stock solid bronze bushing set-up.

bob.
 
I do have a forge at my parents place that might be able to (or be modified to) take the whole axle length for the heat treat. I think that's much more in line with the home brew axle/bearing/swingarm you got going on. Plus saves $$$

That is if you're down for more epic dicking around.
 
got a link to delta cam? 85 bucks for a regrind is a DAMN good deal... I'd send my cam out in a heartbeat.
 
when is a rocker too far gone to reface? i've got two cams and rocker sets, i think i can piece together something good enough for a regrind/face, if i know the acceptable range
 
Im not sure if there is a specified measurement. From my understanding (take it for what its worth) I believe in most circumstances they actually add material in order to set the proper thickness and then grind down to match the cam. Again, thats only my understanding of the proccess, it would be worth giving them a shout to get a solid answer.

Ah, while writing this post I did a bit of research and found this little tidbit in the Megacycle catalog:
Our procedure:
We grind .035" off the existing rocker pad to remove the chrome
plating and prepare the surface for welding. We weld a .040" layer
of nickel-chrome hardfacing alloy to the surface to create the new
pad. We grind, edge, finish this new pad to the correct radius.
The finished depth of the nickel-chrome alloy is a minimum of .035".
This is double or triple the thickness of the original chrome plated

surface on the pad.
Link to the catalog: http://www.megacyclecams.com/catalog/catalog.pdf
Page 11.

Wether Delta uses the same proccess, im not sure.

bob.
 
thanks, that's perfect. that saves me finding another set of rockers in good condition. it's a shame postage from australia is such a budget-killer though. i will try and find someone local who does similar before contacting them though.
 
weird, I had a dream the other night that this thread started up again, haha. Been putting most of my time and cash into my career this past year but worked out some budget stuff with the wife so as soon as we get our tax return you'll be seeing some major progress. I can say that the new shop I'm working at has a dyno and there just so happens to be a brand new half fairing on its way to me... (treated myself for my B-day) so shits gettin serious. Stay tuned.
 
Bump for more updates. Just wanted to let you know I continue to follow your bike's development. Keep up the good work!
 
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