RS Motorsport :: Classic Speed Restored

I recently laid my hands on a set of DHLA 48's, I would prefer using 45 Webers but they are a little rare over here. Anyhow these 48's come off a N/A Cossie rally car so the jetting is obviously wrong as they will be used for road and track days.

What I want to do is flow my Pinto head, fit group 1 valves with WR40 (group 1) cam and run it with the 48's. So I need a basic guide as to jetting the carbs - There were a few spare jets that came with the carbs, I have:

Airs - 180,190,200
Mains - 150,155
Idle Jets - 55
Pump Jets - 45

Chokes are 41 I have heard that 36 chokes should be fine ?
The head has already been skimmed by 1mm when I fitted the Piper 285 last year. The bottom end is still std 205. Is there anything else I should do ?

I have used Dave Andrews chart as reference and found the following:

The following settings are for Webber DCOE or Dellorto DHLA on a 2ltr engine, with max power at 7,000 rpm and set for power rather than flexibility.

Dellorto Carb Settings
Ideal carb size.....48 DHLA
Choke size..........41
Main jets...........165
Emulsion tubes......7772.6/7772.5
Air correctors......190
Idle jets...........50/7850.2 (Weak .6/.1 Rich
Pump jets...........40
Aux venturis........7011.2

cheeRS

First thing is 48s are really to big cept for all out race car.

41 chokes will give poor low speed response, for street car etc.

2 WR40 (group 1) cam is not a good cam...probably was once but now there are faster lifting units to do a better job.

3 U might as well go for group 2 valves 44.5 & 38 mm.

Sorry, realized that this topic should be under the carbies/fueling section

Thing is I am working with what I have at hand, thus I need to know how I can make these components work in my engine. Some drivability would be ok but performance is what I am after - the car is used mostly for shows & track days. I know the WR40 is out dated but it still delivers good power 3-7K.
I would have to ask around for sample valves if I go the 44.5 & 38mm route and the valves I can get have already been made

So can I make these carbs work or do I have to start looking for 45's ?

Thanks in advance

CheeRS

Roger 48's will be fine with say a 38mm choke and will give reasonable drivability and are not for all out race cars only

Danny

i just found my specs from 15 years ago or so .
48mm webers pinto
gp 1 hd big cam
mdm head


38mm chokes 36 mm chokes chokes
3.5 aux venturis 4.5 aux venturis
145 main 135 mains
175 airs 160 airs
emul f18 emul f16
idle 45 f9 same
pumpjet 45 pump jet 40
excel pump 50 ?
getting the mains & airs right after the chokes was the best starting point
i tried a few diferent things in those days
but the 48,s were better than 45,s
these were only my starting point figures from yesteryear but
i think i went to both bigger mains & airs to get it right , but then again i was running full lead super petrol in them days
hope this helps somebody as a starting point
i didnt like the 45,s much / only for low grunt motors
40 mm webers , mikunis & delorto,s etc belong on a hyundai gemini yuk

Many thanks for the info