CB360 Exhaust Sizing Questions

[miks15]

Hi All,

Tried lots of searches but struggling to find exactly what I am after.

I am building a Cb360 (and also have some spare Cj360 engine/parts knocking about). I am going to weld up the exhaust myself (a 2-1) but can't find what the stock pipe diameter is for the CB360, does anyone know? And what diameter is the increased section where it mates the engine?

Secondly, I have some exhaust collars knocking around in my box of bits but don't know whether they are CB or CJ parts. Is there a difference between the 2? (do they both have the same pipe diameter?) If not how can I tell which ones I have?

Thanks in advance!

 

[ridesolo]

Hi All,

Tried lots of searches but struggling to find exactly what I am after.

I am building a Cb360 (and also have some spare Cj360 engine/parts knocking about). I am going to weld up the exhaust myself (a 2-1) but can't find what the stock pipe diameter is for the CB360, does anyone know? And what diameter is the increased section where it mates the engine?

Secondly, I have some exhaust collars knocking around in my box of bits but don't know whether they are CB or CJ parts. Is there a difference between the 2? (do they both have the same pipe diameter?) If not how can I tell which ones I have?

Thanks in advance!

Hey, I'm sorry it has taken someone so long to answer your questions. Rare for this place, usually SOMEBODY chimes in about things. Those collars should all be the same for the CB and CJ. You should have the collars that bolt onto the head as well as the two-piece inserts that go in between the collar and the shoulder at the end of the pipe. If you put two of those inserts together and measure the diameter, that'll be your pipe diameter.

On another note, that CJ360 parts engine you had... if you've still got it do you still have the oil pick-up from it? Thanx, Cory

 

[crazypj]

I would have posted if I saw it sooner. If your building an exhaust, the stock is double wall so diameter looks way bigger than you actually need. I bought a bunch of mandrel bends and made a 'stepped' exhaust for mine then fitted a small 'Cherry Bomb' on the end.

The hardest part was making collector.
As new information on exhaust systems is now available (from NASCAR and F1) I would now make it slightly different with a sharp join instead of the flat that was common for years (mine is somewhere in between)

I think I started with inch and a quarter tube which is inch and one eighth inch inner diameter then used pipe that slid over the outer dia (I think iOD was 1-3/8", then 1-1/2", been quite a few years since I made it)
The outlet to silencer is 1-7/5 OD. I made new 'collars' from 5/8" 6061 aluminium plate and used alloy tube for spacer. Finding a big thick washer was 'fun' as was opening inner diameter to make a flange
Here's a pic of bike lying on side so I could tuck outlet closer to frame (better ground clearance when cornering)
I will do this differently on next system, remove brake pedal and main stand bracket to get a better curve