Bike TB's - Update with MORE pics

waitrose!! i didnt realise that you were that posh mike!!!

 

still good figures to be had i hope.

 

One lives half a mile from the Queen. I'm still council estate trash at heart though

 

Manifold in progress

Old Injector / New Vaccum for the servo



the manifold, see total length, shorter than a biro



looking down the barrels, bit of porting required



blood and all



overview


Its the first attempt bit rough looking, ill start tidying it up later.

comments please...

 

was it not possible to cut the old manifold down so that it was 4 seperate tubes that could be coupled to the tb's with 4 rubber pipes? like on the bike....

 

Hmm...

That's some tight curves for air to negotiate on cyl 2 and 3

May flow a bit worse than 1 and 4 ?

no chance manif could of been longer?

 

i was thinking that if i could use 4 pipes and just cut the manifold flange off and weld them together.

2&3 looks tight but ill see what it looks like when i have opened them out. I can see this being fun and games

 

I'd be worried about the difference in flow too. I'm sure I've seen one before using just the flange and 4 bits of tube like you describe, looked very tidy.

 

You'd be surprised what you can get away with after a bit of porting, though in the pics it does look a bit tight. The Weber carb manifold has more of an angle to it to start with, that would be a better base if you could pick one up cheap. Failing that, angle back the inner ports as best you can, plus there maybe an advantage to filling in the outer edge of the inner runners (if you see what I mean) that you've welded on to blend it all in smoother, at least thats what it looks like in the photo's.

This may give you an idea of the angle...

 

hmm will have a go at opening the ports up, but like you say a weber manifold may be a better starting point.

 

what the spacing between the port on the weber manifold?

 

I'm up that way later today, I'll measure it for you and post it up.

 

Right, the numbers are...

110mm between the carb mounting stud centres and 73mm between the carb mounting studs on the inner port runners, that should give you an idea of the angle you need to achieve.

 

I have measure the bodies, and the spacing is quite different, to the weber manifold, looks like a custom one may be the order of the day.

 

Been busy Porting its still a rough finish but it look like it may work.








What the port used to look like


any idea on best way to check the flow? or is it a specialised job

 

yea it will run .. but isn't ideal

 

the gixxer bodies i have are all seperate, so you could move them apart to match your port spacing

 

the problem isnt the outers it the inners i cant get them any close than they currently are. The outer are almost straight.