hi all

almost there with my bike carb conversion got everything now except the inline fuel filter but they are pence so will be on my next visit to ebay.

just wondered how people have taken their vacume for the dizzy from their home brew manifolds?

my vacume lines are about 4mm internal diameter and i need to run one from the 4th tube to the dizzy

how have you all sorted yours?

Cheers

Ben

Some say you can run all 4 pipes into a small cylinder and one to the dizzy
bogg brothers just set the dizzy too 34-36 %
you really need a modifide dizzy or use megajolt
Jacko

just a thought

do you have to run the vacume from the manifold or can you run it from the air box?

Manifold have a look in my photos under zx9r & manifold

the nuts that have been brazed on are for vacuum pipes and balancing the carbs .
I dont use them now for vacuum pipes know i have a modifide dizzy

view of vac take off pipe nuts

cheers mate

what do you mean when you say

set the dizzy too 34-36 %


or how do you modify the dizzy? sorry for all the questions never done anything like this before.

also i was thinking i could drill and tap the manifold to acept a fuel union

would these be ok to use?

little re think on this I was thinking

first manifold tube:



second, third and fourth:



all connected with



what would I need to run them into before the dizzy?

also I am struggling to find a reducer for the dizzy from 6mm to 4mm any ideas of where to get them?

Too set the timing to 34% use a timing gun strobe] rev the engine to 3000rpm and adjust the dizzy timing to 34/36%
the engine may be hard to start it will be a bit like a flat battery
This is only a temporary thing till you buy a modified dizzy or fit megajolt

think it will definatly be the way to run 4 vacuum outs

would it be best to run them in a continuos line from 1,2,3,4

or would it be best to run individual lines from each to a collector tube ect?

i found that when i ran 4 vacs joined, it affected the lift on the carb slides... the tap offs wernt big to start off with , but i ended up soldering them up and drilling 1mm or so holes thru the solder

so 4 8mm fuel unions may be too much?

also is it best to have them seperate or in a row all joined together?

mig tips!available with 5 or 6mm threads. Cheap and nice small bore.
I would join ideally to a small chamber (bit of copper pipe with end caps, solder on some more mig tips?) or use joiners so joining 1+4, and 2+3 then into 1.
That would be ideal for megajolt too.

But thinking about it, the old alfa engines just had a single take off no1 inlet with the dcoes/dellortos.
Hmm, that would be easier....

just been reading

http://www.turbosport.co.uk/showthread.php?t=141555

and they seam to think it is not that important to run the vacuum

i am getting confussed now what is the main benifits?

quote:

---

Originally posted by cliftyhanger
mig tips!available with 5 or 6mm threads. Cheap and nice small bore.
I would join ideally to a small chamber (bit of copper pipe with end caps, solder on some more mig tips?) or use joiners so joining 1+4, and 2+3 then into 1.
That would be ideal for megajolt too.

But thinking about it, the old alfa engines just had a single take off no1 inlet with the dcoes/dellortos.
Hmm, that would be easier....

---

Vacuum will allow extra advance on light throttle openings, allowing a better burn and more economy. Thats the main thing it does.
The cannister is to smooth the pulses from the 4 take-offs and give an "average" vacuum. This is more important with a megajolt with MAP sensor which will respond faster than the vac advance on a dizzy.
Oh, and I doubt joining the intakes will affect balance at all. Just that when you do balance the carbs probably best to blank them all off to be on the safe side.

[Edited on 25/3/09 by cliftyhanger]

Little update:

happy as a pig in the brown stuff my manifold came back today so got the silicone out and it looks good. just waiting on the jubilee clips to arrive and a 10mm union to tap in for the brake servo and then a 6mm union to tap in for the vacuum





Cheers

Ben

the worlds smallest update:

took the manifold to work today so i could get a couple of blobs of weld on the runners to help keep the jubilee clips in place and also a little spot where there was a tiny hole on the weld holding the tube to the base..

fingers crossed the jubilies arrive tomorrow.

also ordered the transaxle plugs from audi to fill the injector holes so they can be collected saturday, i really can t wait now almost there.



Cheers

Ben

What car is this going on ?the size of that manifold it cant be a 7 type can it

A brake servo too

on my porsche 924 2ltr

it is 300mm from back plate to tip of trumpet which should be ideal from what i can gather for the engine ect

another little update:

painted the manifold in matt black bar b q paint so at least it wont go rusty.



also just got the unions for the vacume take offs a 6mm for the dizzy and a 10mm for the brake servo.

think i need to weld a nut to the manifold tubes and then drill through the middle before screwing in the unions.

Any other options for mountin these unions?



also got my silcone friendly jubilee clips



and then the transaxle plugs arrived to block the injector holes.



trying to get it booked in for rolling road on the 16th aprill so fingers crossed it will all be sorted soon.

Any ideas on the vacume take off would be great.

Cheers

Ben