Jetting for Solex C40 ADDHE with modified 130 TC engine

[Abarthnorway - Remi L]

Hi Guy!


Here is another jetting question for You:

Engine: 130 TC Standard components only destined for racing series

Mods:
Ported/Flowed/Balanced/Deburred at my best effort.
CR 10:1
Cams timed 102 in/ 105 exhaust - tighter clearances
Advanced ignition timing by 2`
Std tubular manifold - straight free flow exhaust


Carbs: Solex C40 ADDHE Sport (as fitted to 130 TC)

This Carb differs from the normal ADDHE by having a mouth of 45 mm all the way to venturi choke, and differently designed emulsion tubes, air/main jets.
Original jetting:
Venturi 32 mm
Main jet 145
Air corrector 190
Ram pipes ID 45 mm 43 mm length

Planned mods:
The carb will recieve longer (approx 80mm length) ram pipes with 40 mm ID....

The original jetting of these carbs seem to be a bit "off" compared to what is recommended elsewhere......
I have choke sizes 34, 35 and 36 available + I can finally source any wanted jet size.


What setup would You use as a starting point?

Chokes?
Mains?
Airs?
Any advice against changing rampipes?

Thank You!


Best regards

Remi Løvhøiden




Solex C40 carb mouth - 48 mm without ram pipes.... 45 mm all the way to venturi chokes with std rampipes fitted




This engine now in pieces again for redoing and checking a few details

[Guy Croft]

Hi Remi

for starters - very sorry I have not yet been able to devote time to your downdrafted head idea.

As far as this setup is concerned that unit should pull 34mm chokes comfortably.

For jetting:
145 main is OK
Air corrector 180 probably better, bit richer at top end.

Ram pipes ID 45 mm 43 mm length - can't really comment except to say that longer rampipe for given ex header setup will bring the torque in at lower rpm but they are generally pretty short on all OE carb setups and you may notice no difference.

Well done with your various TC projects, always interesting!

G

[Abarthnorway - Remi L]

Hi Guy!


Thank You! No rush with replying on the downdraft version - its a future project...

Will be fun to play around a little with the standard engine, especially curious of the effect of timing the cams differently.

Will order a good selection of jets shortly for the carbs.


Best regards

Remi Lovhoiden