6 replies to this topic

[Earwax]

I have a number of differing weber manifolds, of which the majority have no dizzy vacuum port - some have a servo port and this makes sense as in a majority of cases fitment of a weber is about top end performance.

 

But in the 3 1/2 variety - made for road use and not interfering with the firewall, i have the normal setup as above but i have 1 redline with a vacuum to dizzy port and 1 Cannon with a balancing tube ( albeit within the casting)

 

My question - has anyone been able to successfully pair a vacuum dizzy advance with the weber induction characteristics and if so what secrets - in my attempt the vacuum connection pulled the advance into the climbing part of the curve and made idle circuits not work.

 

and secondly - the purpose of the balancer arrangement ( either on weber or SU) -  any info welcome.  Sorry can't provide pictures at the moment am away from home 

[KernowCooper]

Trouble is webers are race carbs and therefore no provision is provided behind the butterfly for a vacuum take off, if you use a manifold take off the vacuum see's engine vacuum and therefore not ideal. Its a problem using a distributor with vacuum advance and a weber. whats the spec of the engine ? and what distributor are you using.

[albo]

weber`s are race carbs ?,,you mean high performance carbs when needed,, in the correct engine and set up right a weber will give perfect all round performance to meet your engines demands slow and at high speed ,,besides its good looks it`s not realy at home in a mini,, twin weber`s  set up`s as in lets say alfa suds ,,they woud never missed a beat,,it`s a shame they rusted away before they had chance to

[Bungle]

a dellorto carb is very similar to a weber carb but does have a vac port on the carb body

[KernowCooper]

Webers were designed as Race and high performance carbs yes, hence no need for economy take offs for vacuum advance, and yes as bungle pointed out Dellortos do have a proper vac take off.

[Earwax]

Hi  and apologies for being away from computer.. not ignoring replies. I know the full on version of the DCOE 45 was well suited to racing on a long manifold .... i have one of these and it goes great on the Appendix J (Group N) racecar... i suppose i am curious about the 3 1/2 inch manifolds , obviously made to suit the purpose of fitting without firewall mods, but also then presumably made for a more tame style of engine. 

I do think a well sorted weber can be reasonably economical but IMO not as economical as a SU.. and perhaps the difference is just the vacuum???    But i do have a short cannon weber manifold that has a internally cast balancer section similar to twin SU manifolds,, and i don't really know what the balance mechanism was for?  To KernowC... the motor is a 1310 road car, so probably on the edge of a 40/45 spec ( was going to try 34 chokes on a 45 to start)  

 

I was not aware dellortos had vacuum connections , i'll have to go back and read my des hammill books.. Cheers for replies

[KernowCooper]

Another Des Hammill book worm lol