Topic: Project "Evolution" 78' CB750K... the morphing continues...

[madmtnmotors]

Well, I figured a drag bike should at least be sporting drag pipes, especially since I've had a set hanging from the rafters for longer than I can remember. While I was at it I went ahead and sprung for a set of Steel Dragon's velocity stacks. Now I typically refrain from putting form ahead of function, but velocity stacks are just too dang cool... and their name even sounds fast!
















I got schooled on drag pipe installation as well. Turns out the left side pipes won't clear the kickstand spring (at least on a K8 anyway). I had to move the spring from the front (outboard side) of the kickstand to the back (inboard side):






Even after lowering the front by 2" and the rear by about 1-1/2" you'll notice that the center stand only lifts the rear by about 1/2". That's because the centerstand is from a GL1100, and it's a direct bolt on. Just had to weld on a spring hook since the GL spring hook was on the wrong side. The stock 750 centerstand would hold the rear wheel almost 4" off the ground. I had to roll it up on two 2x4's just to use it. With the GL centerstand I can roll the bike up with just one hand on the bar while stepping on the lever. 

[calj737]

Pics aren't showing, Wilbur---

[madmtnmotors]

Pics aren't showing, Wilbur---

Hmmm... I've attached the photos to the previous post to see if that will coax a connection to Google-fu. I have seen sporadic broken links to the Google photos but it will usually resolve itself eventually. 

[Stev-o]

Looks good Wilber!  Should drop your ET's by at least .5 sec!!

[seanbarney41]

whoa there Steve-o!  half a second would would be a quite significant improvement!  I never figured on those "drag" pipes actually having any performance improvement whatsoever.  But then I always ditched 'em for ground clearance reasons...not an issue on the strip.  Curious if you did any street tests after installation or any jetting changes?

[madmtnmotors]

Looks good Wilber!  Should drop your ET's by at least .5 sec!!

whoa there Steve-o!  half a second would would be a quite significant improvement!  I never figured on those "drag" pipes actually having any performance improvement whatsoever.  But then I always ditched 'em for ground clearance reasons...not an issue on the strip.  Curious if you did any street tests after installation or any jetting changes?

LOL! Don't know if there will be any performance gain, simply an indulgence. I'll likely sync the carbs, do some plug chops, and index the plugs next weekend. 

[Stev-o]

Looks good Wilber!  Should drop your ET's by at least .5 sec!!

whoa there Steve-o!  half a second would would be a quite significant improvement!  I never figured on those "drag" pipes actually having any performance improvement whatsoever.  But then I always ditched 'em for ground clearance reasons...not an issue on the strip.  Curious if you did any street tests after installation or any jetting changes?

LOL! Don't know if there will be any performance gain, simply an indulgence. I'll likely sync the carbs, do some plug chops, and index the plugs next weekend. 

Ha.... wasn't being serious about the ET times but I bet it will feel more powerful on the butt dyno!

[madmtnmotors]

I bet it will feel more powerful on the butt dyno!

That's the only one that matters! 

[Don R]

  Back to your jetting, we had jr dragsters and when we went from stock stroke to the +.563 stroker cranks we actually needed a smaller main jet. The extra pull on the intake made the carburetor work better with the components we already had. I ran a 30mm lectron, most guys had a 28mm mikuni.