Topic: 6spd finally complete

[bwaller]

Well nearly.  

To update, this is based on CB360 stuff shoehorned into 550 cases. Ellis at Moore Performance Engineering made me five different gears and a new mainshaft to tighten ratios a bit. He did a nice job. These are not Yosh type ratios, but for reasonable money will be an improvement over original.

2.125:1
1.65
1.333
1.111
1.0
0.929

Overall reduction is 56.3%, but 1st gear will be launch only with 2nd through 6th at 43.7%




I asked the shop to undercut the engagement dogs full length because this gearbox shares little with the original, different shimming, dog width, etc. Well they didn't so I will finish this work by hand.





Getting the thing to fit the 550 cases took the usual machining, engine cases, gear width, bearing case widths. Fiquring the shift fork shaft placement and altering the drum took the most amount of head scratching.


All the gearbox bearings sat inside the engine cases somewhat and these needed to sit flush to gain space. On the mainshaft I used a different needle bearing and repositioned the locating pin, the opposite end ground 2mm off the outer race. On the countershaft the needle bearing case was ground thinner and a thinner 650 needle used. A new locating ring groove was cut (in the upper case)to position the opposite ball bearing outward. This means less space for the seal, but I made a seal retainer to help make sure it stays put.



This is the thinner bearing that sits flush.





This is the original. It doesn't show but it protrudes 2mm or so inside case.




This also shows the new retaining pin & ring positions for MS bearings.




Here is the 550 drum on top with the original 360 piece.





Two 360 shift drums, I'm commited now!





550 drum in center, 360 right. Machined the drum and then silver brazed a stub shaft the proper length to attach the modified drum end. When finished this will allow use of all the 550 shift mechanism.





Cut off 360 drum end compared to the 550 piece.








550 left, finished part in the center, 360 right





I wanted to use all of Hondas improvements in transmission lubrication so machined the mainshaft for the "oil auger" and the countershaft to accept the drive for the trochoid pump.







/edit : removed links to photobucket at bwallers request~mlinder

[MRieck]

Wow...great work Mr Waller. Fantastic. I can't wait to see this bike together.

[bwaller]

This post has been interupted several times & I didn't finish. It doesn't appear as though my pics are what I was looking for. I'm lacking in computer knowledge.

Maybe more later.

[MRieck]

This post has been interupted several times & I didn't finish. It doesn't appear as though my pics are what I was looking for. I'm lacking in computer knowledge.

Maybe more later.

You more than make up for it in other areas.

[cb750k77]

so you will have a 6spd 550 is that what i'm reading here??? any chance of getting a 6spd 750?

[MRieck]

so you will have a 6spd 550 is that what i'm reading here??? any chance of getting a 6spd 750?

I was waiting for that question.

[paulages]

brilliant work,  brent.

[Bill/BentON Racing]

Brent,I knew you'd get it done! WOW,sure is nice and well sorted it appears.You the man!,Bill

[mlinder]

I need to figure out how to get one of these in a 350t 

Nice work, bwaller.

[bwaller]

Thanks for tuning in guys. No plan for the 750, I'll leave that for Mike! 

Early on my wife asked what I would do if the thing blew to hell in the middle of turn one somewhere... I told her "crash I suppose".

[MRieck]

Thanks for tuning in guys. No plan for the 750, I'll leave that for Mike! 

Early on my wife asked what I would do if the thing blew to hell in the middle of turn one somewhere... I told her "crash I suppose".

  No,no,no,no Brent....I politely decline on that one. 

[Sam Green Racing]

Ellis is only about 5 miles from me Mike, I could ask him for you.

Sam.

[MRieck]

Ellis is only about 5 miles from me Mike, I could ask him for you.

Sam.

I don't need anymore on my plate Sam. Great Pub conversation though.

[Sam Green Racing]

JMC really did upset you, didn't they.

Sam.

[turboguzzi]

hei brent, my head is spinning form just imagining all the work you've done! wow....

the million dollar question:

does it actually shift all the gears? 

mlinder, all you have to do is get a 360 bottom end, no?


TG

[mlinder]

hei brent, my head is spinning form just imagining all the work you've done! wow....

the million dollar question:

does it actually shift all the gears? 

mlinder, all you have to do is get a 360 bottom end, no?


TG

350 and 360 bottom ends are pretty different. I don't think the 6spd from the 360 is a direct swap... or so I've heard.
But yeah, I need to get a 360 bottom end to see if I can't fit, somehow, the 6spd into the 350 bottom ends.

[turboguzzi]

I thought about a complete swap, a 350 top on a 360 bottom,

not that i know much about twins....

[mlinder]

I thought about a complete swap, a 350 top on a 360 bottom,

not that i know much about twins....

350 top end does not fit on 360 bottom end. They are not similar. Also, if you used the 360 bottom end, you'd be going from a 180 degree roller-bearing crank to a 360 degree solid bearing crank. Not a good trade off, IMO.

I'm just going to buy a 360 transmission and see if I cant find a way to make it fit in the 350 bottom end.

[bwaller]

mlinder, that's the right plan, buy a used 360 gearbox and take a look. I dug out some 350 cases a while ago and they are the same width as the 550 so the clusters can be made to fit.

The sticking point will be the shift drum. The 360 drum tracks are more closely spaced and there won't be enough space for the three 350 shift forks. I don't recall if there was room to "hang" the separate 360 shift fork shaft like I did on the 550 and just use the single fork on the drum.

The plot thickens, go for it.


I've got a few more pictures.

Shift fork shaft hung from the top case by steel angle pieces because of the difference in selector forks/drum meant the original 550 fork shaft and hole position in the engine case couldn't be used. This is mock up stuff understand, there was lots of tidying up afterwards.








By moving the needle bearing outward on the countershaft the oil feed hole in the bottom case for the trochoid pump had to be plugged and redirected further outward. I had to grind the locating flange (for that tiny pump) off the case and alter the inlet hole in the pump so it would align with the new oil passage.


Original passage





New position





Altered pump inlet


 


With the pump outboard of original position in the case, the shifter shaft needed to be modified to clear








OK I'm sure this has gotten boring, I'll let dead dogs lie!  

[mlinder]

Very nice, Mr. Waller.

[MRieck]

Very cool stuff Brent. I can see you pondering this stuff lying in bed trying to sleep. That's how it gets done.

[bwaller]

Very cool stuff Brent. I can see you pondering this stuff lying in bed trying to sleep. That's how it gets done.

Talking from experience no doubt. 


Oh and TG, it shifts sooooo nice.

[Hasenkopf]

ALL YOU NEED TO NOW IS OFFER THIS AS A "KIT"

[MRieck]

JMC really did upset you, didn't they.

Sam.

Funny you should mention JMC. I just picked up the polished arm this past Saturday from Alister. It is stunning

[Bill/BentON Racing]

Mike,is that an arm for a CB750A? Yeah Brent hijacking here,sorry,Sam snowing in GA.I guess the sleds will be happy ;)Mike mailed out $ this morning.Thanks,Bill.....Brent,the SOHC Creative Engineering Award 2009 goes to you! 2010 for Voxonda's dry clutch,Vox get busy  ;)way to go Brent,how many orders you got?