Italian webber carbi?

BADGEM · tinkerer Joined: 05 Nov 2001 Posts: 195

hi guys I got a question I want to fit twin webbers as big as possible ? down draft.
I got a single webber put its not enough for me .
I got a mate who owns an alfa, and his got twin webbers,
would I be able to fit the webbers to my Gem?
most webbers are italian aint they any1 got any ideas?

Frederick Stienheld · petrol head Joined: 05 Sep 2002 Posts: 2719

Yes you can put twin webers on a gemini, I have them on mine. There are italian made and also I think spanish manufacured webers available. Why do you want downdraught? as far as 4cyl engines are concerned sidedraught is a better option performnce wise. For sidedraughts you would need a TX remote brake resovior though, which is the only reason I can see that would sway you to use downdraughts instead. I also don't think you want to get them as big as possible, if the throats on your webers are too big then you lose too much airspeed and you will be down on power compared to what you could have been with a smaller set of webers so you don't want to go too big. Similar to an exhaust system you want to get the right balance between out and out size and practicality. Hope this helps.

FJ20DET · tinkerer Joined: 06 Oct 2002 Posts: 191

down draft so he can have the filters poking out the bonnet Very Happy

TXcoupe · petrol head Joined: 05 Oct 2001 Posts: 1675

i would go down drafts as the flow better than side drafts for a gemini.

My gemini has been flowed with twin down drafts at 210Hp

Adam · Site Admin Joined: 04 Oct 2001 Posts: 682

My head guy (Peter Liddle of Liddle Cylinder Head Engineering) concurs that Downdraughts (twin 44mm) flow better on geminis.

TXcoupe · petrol head Joined: 05 Oct 2001 Posts: 1675

u mean agrees adam
a flow bench is a wonmderful thing but you dont win races on the bench u win them by using the bench

CuGem · backyard mechanic Joined: 07 Oct 2001 Posts: 599

hahaha, Peter asked me why I wanted to put that bucket of shit S-bend manifold on my gemi, when I took it to him to true it up! He's definitely a DD fan. Has a gemi for hill climbing is that right?

MrSHADOW · tinkerer Joined: 15 Oct 2001 Posts: 95

I got my best HP results using twin 44mm DD Webbers on a FET intake manifold, the airspeed and atomisation of the fuel was better than with the twin SD Webbers I tested.

Spend a few extra $'s and get it flow tested, then hit the dyno and play around there with carby setups.

Frederick Stienheld · petrol head Joined: 05 Sep 2002 Posts: 2719

I consider myself corrected!
My uncle has about 240HP out of his L20B in his datsun 1600 and he's using twin 45 DCOE9 webers (sidedraught) and he gave me the impression that sidedraught was much better for straight engines because the fuel flows straight in and downdraughts were better for V engines becaust the mixture flows straight down into the valley, obviously downdraughts work better on gems. Makes me glad I got my hands on a set of DD's and not SD's

rednipper · rice boy Joined: 10 Aug 2002 Posts: 17

well from wat i understand - my point of view
side drafts work GOOD on a engine that has a stright manifold or a straight sloping manifold
but becuase the gemini has a S shape manifold it ruins the flow charastics of the side drafts. and as the down drafts have a less bend in them this gives the better flow and probaly qwiker air velocity. and fast flowing air is wat helps make power Smile

Frederick Stienheld · petrol head Joined: 05 Sep 2002 Posts: 2719

Power is good