Topic: 1973 CB750 Four K3 -- Project "Terry's Fault" -- BUILD RESUMED

[edwardmorris]

If you plate them, do so before packing them. Removable end cap. Polished aluminum will look like plated and be easier to fab.

Even if played, you want them ceramic coated inside.

Cut off either way, whichever is more available

I don't have access to or know anyone local who can fab one on a lathe, unfortunately Aluminum end cap can also be powdered black for added accent??

Ceramic: Are you talking about plating the inside of the outer 3" dia tube? Or the inner holey one or both? I'll ask my coater and plater about working this out.

Have both dremel and angle grinder, scared of the latter so will start with dremel first, thanks!

[edwardmorris]

Coating inside provides benefits of corrosion prevention, efficiency of exhaust scavenging, and does reduce the a,being temperature of the exhaust pipe.

Coating the outside only provides minimal added ambient temperature reduction, and some cosmetic improvements.

So inside behind the glass packing is cool? Or should it be on the flow path (inner holey pipe)...

[BPellerine]

just my two cents worth but the pipes you have in mind don't flow with the old bike at all to me,they look like the pipes on one of the newer Yamaha cruisers ,I would take my time and look at some more designs,but it is your bike man,enjoy!bill

[edwardmorris]

just my two cents worth but the pipes you have in mind don't flow with the old bike at all to me,they look like the pipes on one of the newer Yamaha cruisers ,I would take my time and look at some more designs,but it is your bike man,enjoy!bill

I have a very specific look in mind, and I just googled yamaha cruisers, you're right, they're similar. I haven't yet talked about the heat shield I have in mind for this one, so I'm optimistic that the final look will be good. This won't be like my OCD K2, rather this build will have a lot of modernization (at least whatever I can afford) and hopefully fun to tinker with new things that I didn't get to do with the K2.

Appreciate the feedback though, if you have any recommendations on better designs, I'll gladly look into them.

[edwardmorris]

When I picked this one up, I had a very specific look in my mind. Its scary, how so far, I've managed to get what I want!

I wanted an early K, and landed K3 #225 (practically a K2)!
I wanted to use the old K0/K1 style tail light, the K3 came with it!
I wanted better engine mounts and Frank just dreamed up the perfect ones!
I wanted a correct looking custom/mag wheels to go tubeless and I landed these!

Should I be worried??

[BPellerine]

things are going too well?your uncle terry has what I would call a good look for these old bikes,it is very hard to integrate new with old and make it look right,I cant even make up my mind on mixing old with old,so what do I know!BILL

[seanbarney41]

not so fast Ed...I don't think Lesters are designed to run tubeless

[edwardmorris]

not so fast Ed...I don't think Lesters are designed to run tubeless

I'll ask Dean to look for the T or TL sign on them, thanks!

Info

http://forums.sohc4.net/index.php?topic=80350.msg898822#msg898822

[754]

The tubeless version should have small shallow groove where the bead seats.
 
Here is what I had in mind for exhaust tips, along these lines..
 Excuse the oily end.

[edwardmorris]

Frank, that's pretty close, I'll PM you.

Here is idea #2 that I'm now considering, I can see a bunch of headaches with the 4-4 parallel custom design the more I think it through. This is one is simple, use  2-1 collectors and single glass pack muffler on each side.

1 = 3-1/2" dia
2 = 3" dia

Inner holey tube will be 2-1/2", same as the outlet of the collector. 1/2" difference on ends makes it a less obnoxious cone, but will most likely need to be rolled from sheet. This design also cuts the end caps down to half.

Anyone good with rolling steel  ?

[goldarrow]

I'm so proud of my k5 ^^^

[edwardmorris]

I hope you don't mind me using the pic gold dude 

What exhaust is this? This would be ideal if it isn't custom.

[SOHC4 Cafe Racer Fan]

That's a gorgeous Seeley tank.

[754]

Do you mean rolling a cone? Check out Cone Engineering..

[edwardmorris]

Do you mean rolling a cone? Check out Cone Engineering..

They don't have the specs I need in their catalog. Do they do custom stuff?

[SOHC4 Cafe Racer Fan]

Yes, they do. Nice people, too. They supply to numerous pro builders who rebrand.

http://www.coneeng.com/pdf/Custom%20Cone%20Request%20(worksheet).pdf

[edwardmorris]

Thanks Don, will give them a call soon! Looks like I'll be needing custom collectors too, everything on their catalog is too short (for use with the stock headers).

I removed the banged up kerker and installed a set of stock headers and spigots ( gamble purchase as of now, if it work great, if not, more work time to fill the hole ). The seller seem to have managed to cut them pretty close to size, now I need to roll this beast over to the machine shop sometime and start working on the inner holey pipe and bends, maybe even attempt making a collector?

[edwardmorris]

The pain point when removing the kerker (and trying to install the spigots) was that it was barely hanging by a few threads on the #2, #3 and #4 ports. There was so much rust and crap on the bolts, I bet the threads are full of crap by this point. I tried and scraped out what I could with a wire and sprayed some CRC to knock it loose. Worked just enough to get the spigots installed with more than half the screw length for now but will need to be fully cleaned.

Lesson for my K2 assembly: Install the spigots while the head is out of the frame, its a PITA trying to get the right angle to screw things in with the frame and front end pestering you.

[edwardmorris]

The tubeless version should have small shallow groove where the bead seats...........

The lesters arrived! They do say TL on them but its very hard to see the shallow groove. All the reading I did on the subject suggests that I run a tube even on the tubeless rated ones, so no biggie. They still look so cool! Does anyone see the groove?

[SOHC4 Cafe Racer Fan]

Awesome hoops!

[edwardmorris]

Thanks Don! I'm glad I won't be lacing and truing this time

So I think I finally settled on option 3 for exhaust and moving forward with it. Sorry if I'm boring people, just talking out loud here in case someone has some advice. Looking for someone in the area who owns/has access to a slip roll to get a prototype going for the muffler. One of my buddies at the local autoshop was interested and offered to make a prototype collector for me, I hope it works out

Tail end 4" dia
First joint 3-1/2" dia
Collector out leading into the holey pipe is 2" dia

[edwardmorris]

Mocked it up today with cardboard, 4---3-1/2 cone is getting to be too large, have to dial it back down to the original idea of 3-1/2---3 cone, but the lengths and angles worked out perfect. Hard to see in the pix as I couldn't push myself back far enough to show the length correctly.

[edwardmorris]

So, its been a while, been working a lot and waiting on some parts to get the exhaust done. Minimally I need the center stand to get the clearances sorted out with the pipes. Had some free time to mess around with custom faces, so I scanned in my old ones and photoshopped them to this. Thoughts? The ones on the left are using a futuristic font, and on the right its the stock font. Obviously these aren't finished and I've held back some elements that will fill out the gaps when I'm done.

[edwardmorris]

Even with LED backlight and a 60% through clear back plates?

[edwardmorris]

Gauges sorted. Will post pix when I have them assembled, black and blue worked out fine with exactly the amount of illumination I wanted. Hit up Tige for suggestions with LED set up and he gave me some pointers, great guy. I'd share the mock up but that'll give away the theme  so in time

Well, the K3 drew blood today, busted up a finger trying to straighten out the center stand mounting tabs that were bent jackschit. Center stand, chain guard and some other goodies arrived from Bill Benton. There was no way I was going to throw my back out trying to pull one of these beasts up on the center stand. So I used my shiny new motorcycle lift to prop it up and swing the stand under it 

16" wheel is too small, look how far up in the air it stands, crazy  I'm glad I had the K2's stand chopped an inch. This one will follow.