Which Carbs?

[C-S_Cormac]

Well i was considering 40's for my 2L 8V nova but have been told that they might be too small and not deliver enough fuel for my engine.. Would 45's be a better option???

Its seems easyer and cheaper to get 40's tho so what shall i do?

[dunova]

Yes you really need 45's on a 2ltr. Infact i was told, if i bored out to above 1650cc then 40's may not be large enough. 45's aren't too much more on ebay.

[burgo]

45's for a fairly standard 2l if its a mad race beast though you'll be wanting 48's

[C-S_Cormac]

The engines had a full bottom end rebuild, rebored etc, running a 1.8 big valve head at the moment, Wen i get carbs ill prob get a cam aswell and get the head flowed....

So 45's would be best,, would 40's work ok tho?

[burgo]

40's would struggle to deliver the amount of fuel you need so id say you run the risk of fooking ya engine

[C-S_Cormac]

Would anyone know the quater mile time of a standard redtoped nova? mines doing it in 15.5 seconds @santa pod,,, The carb setup+cam im thinking off is gonna cost me in the region of ?500 then sum headwork could end up at the ?700 mark :o which is way over budget tbh im no on the notion of a redtop conversion... would cost alot less than that im sure..

[Philsutton]

times for standard 16v novas vary from mid 15s to low 14s mine did it in 14.6 standard. Then 14.5 with a bit of work.

[C-S_Cormac]

I need some advice guys dnt really know what to do, would like to do all the work on the 8V engine buts its big money :?

[MC]

Ignore the post about not delivering enough fuel.

You can plot the flow rate of carbs depending on size and choke size. The cross-over point between needing 40s and 45's is when you hit 33mm. A set of 45's with 34mm chokes will flow better than a set of 40's with 34mm chokes, and a set of 40's with 32mm chokes will flow better than a set of 45's with 32mm chokes.

Fuel is easy to deliver, but using too small a carb or choke will stifle the engines performance.

MC

[C-S_Cormac]

So a set of 40's would be ok then? You can change the chokes anyways cant you?

[MC]

No, I was just pointing out that too small a carb would restrict airflow, not fuel flow.

You'll need 45's!

MC