05-07-2018, 10:52 AM
The jets in your current setup is way out,
Remember you are now feeding four cylinders of two barrels. You will need to get much larger main jets as per Vizard, Pump jet needs to be much larger again because it has to feed two cylinder per barrel. What venturi size are you going to run? the max on a 40 is 34. You will need F16 emulsion tubes, F9 are quite common but they don't work well.
The Vizard rec's are a good start. We ran a 40 DCOE with 34 venturis, F16 emulsion tubes, idle jets were 55f2, mains were 142 and air correctors were 190, on 1380 with 649 cam, two short ram tubes inside a K&N filter. It pulled really well from low down and made plenty power up to 7000Rpm. Head was just cleaned up, nothing radical, LCB etc.
Remember you are now feeding four cylinders of two barrels. You will need to get much larger main jets as per Vizard, Pump jet needs to be much larger again because it has to feed two cylinder per barrel. What venturi size are you going to run? the max on a 40 is 34. You will need F16 emulsion tubes, F9 are quite common but they don't work well.
The Vizard rec's are a good start. We ran a 40 DCOE with 34 venturis, F16 emulsion tubes, idle jets were 55f2, mains were 142 and air correctors were 190, on 1380 with 649 cam, two short ram tubes inside a K&N filter. It pulled really well from low down and made plenty power up to 7000Rpm. Head was just cleaned up, nothing radical, LCB etc.
![[-]](https://samini.co.za/images/collapse.png)
