another question about webers!

[chris perry 1]

dear all,

 

my standard 1600 8v vauhall with twin 40's has the following jetting.

 

chokes 30

main jets 115

air correctors 195

emulsion f7

idle 50f6

 

this is as supplied by caterham from new and runs rich. has anyone changed these settings to better effect? if so what.

 

please no snide comments about buying a k series!

 

thanks in advance.

 

chris perry

[Graham Sewell]

From DVA's program:

Ideal carb size 40 DCOE

Choke size 30

Main jets 120

Emulsion tubes F15/F9/F16

Air correctors 170

Idle jets 45f9

Pump Jets 35/40

Aux Venturis 4.0

 

These basically work from the standard of getting the choke right and most of the remaining values are fixed increments/multiples. Incidentally, these values were genrated for 1600cc with max power at 5800rpm.

 

My understanding is that mains = choke*4; airs = mains+50; not sure about the remaining values.

 

Low tech luddite - xflow and proud!

[Super_Rich_Bernie]

Chris

 

The car I had until late last year had the carbs rejetted by its previous owner. I can't tell you what the new ones were but seem to recall 34mm for the choke. Mains were bigger too, and idle jets changed - though not sure what else. It ran very well with no flat spots, and pulled from low revs easily.

 

If you try a search on this forum you may find more details since I'm sure I posted about it a while back when such things were being discussed.

 

The way the 1600 Vx engine is fitted in the Caterham necesitates a horrible inlet manifold to clear the chassis diagonal. The mixture has to navigate a couple of tight bends between carb and combustion chamber to get where it needs to be. This is one of the reasons these engines are less 'tunable' than other options. I'm also told it has some impact on selection of jetting.

 

Jonathan