Topic: Pipe-to-Head Exhaust, fixing method

[beveldrive]

I'm confused
In my research there seems to be several exhaust pipe-to-head clamping methods used across the sohc 750 range.
Mine, a K7 with Motad, has the ends of the pipes formed into a narrow flange, all held in place with split collars, M6 studs and finned clamping ring. Then on some I see a drilled diamond shaped flange, loose on the pipes. Presumably this locates on studs and facing a ridge on the pipe, provides the clamping with no finned ring at all!

Can either method be used on the sohc 750 - assuming the profile machined/cast into the port opening is the same for all motors?

Thanks
Steve

[scondon]

Yes, both methods can be used. Kerker pipes are a common aftermarket exhaust for the 750's and have the diamond shaped flange you speak of. Diamond flanges can be bent if over torqued, finned collars are more robust. Bent diamond flanges don't affect seal, they're just a little harder to locate over mounting studs.

[fishhead]

Either method can be use to attach, but sometimes there can be interference at the rear muffler mouting area or underneath.
 Here are the 2 stock styles header mount
 Early ' spigot" mounts

 Later split collar mounts

[Johnny5]

It's certainly easier to mount the header to the earlier flanges than the later style. But I wonder if the later style mounts get a more positive lock onto the head?

[beveldrive]

Thanks Guys, Things are getting clearer now!

How all this question came about was I'm rebuilding my K7 in the style of an endurance racer and have recently got a new (but old stock) Marvick 4-into-1 off ebay. What I want to do is spring mount it. Looking at some pics of a Lawson Replica Kawa, this seems to be acheived by having flange plates mounted to studs about 50mm off the head, and the pipes a sliding fit in the plates. Trouble is, to do this I'm gonna have to cut the pipes to get the flanges on

[voxonda]

Hey Beveldrive,

Like to see pic's of your bike, am a endurance fan myself. This is how I am doing it with the engine I am building now.



Good luck, rob

[CBJoe]

Pardon my ignorance, I've only had CB650's with the split collar mounting type.

I thought that the header pipe mounted "over" the spigot and not "into" the spigot.  What seals/holds the pipe in the spigot above??

Regards, Joe

[voxonda]

Pardon my ignorance, I've only had CB650's with the split collar mounting type.

I thought that the header pipe mounted "over" the spigot and not "into" the spigot.  What seals/holds the pipe in the spigot above??

Regards, Joe

Hey Joe,(Great song, isn't it?)

You are right. This was the setup for my Turbo engined CB750, and I used a smaller diametre tube for that, due to gasspeed in the system. For a 'normal' 4 into 1 the diametre will mount over the spigot's. For the Turbo I used a sealent from the automotive industry, sorry but forgot the name.

Cheers, Rob

[beveldrive]

Hey Rob,
that's a nice bit of machining on those exhaust clamps!
I don't have any pics to show yet as my bike is in its very early stages, but I'll be posting some when things develop.
At the moment I'm waiting for parts to refresh the motor - chains, seals, gaskets etc.

Regards
Steve

[voxonda]

Hey Rob,
that's a nice bit of machining on those exhaust clamps!
I don't have any pics to show yet as my bike is in its very early stages, but I'll be posting some when things develop.
At the moment I'm waiting for parts to refresh the motor - chains, seals, gaskets etc.

Regards
Steve

Hey Steve,

Anything special to be done to the engine? Or refreshing it and give her a good tune?
Clamps made for my (ex) Turbo bike and made new ones for the engine I am building now. Clamps can be made available. Hope making her fast but still reliable.
Been riding my sons Triumph T595 for a few days now and man wished we could make the old girl fast enough to keep in her wheeltracks. Or am I just getting a bit old for these new(er) toys?

Cheers, Rob

[babyfood1217]

I have always love these setups.  I usually see them on race bikes when I go watch the track days, but I think it would be super simple to mod the already existent spigots I've got to make something like this happen.



Has anyone else thought about or tried something like this on these older bikes?