Race Engine Forum UK

Guy Hi Again,
I am setting up the IIIa cams at the moment. I am installing them at 110 LC intake and exhaust as opposed to 105 LC that would be used on an all out race engine.
Also rough jetting the IDF's. Can you suggest a solid starting point for sea level operations

Does this sound ok to you?
Spec refresher.
2050cc T/C Fiat
fFully ported and deshrouded
42.5 and 37mm valves
10.1-1 comp
40 IDF W/34 chokes
Ported "waffle" manifold
4-1 header and 2.5 and straight through perforated core muffler

Again, you have been a great help.
Robert and Holly

Rob, hi

40 IDF 34mm chokes on that setup:

Emulsion tubes F11 (or maybe the richer F9)
with prelim jetting:
Mains 140 (may need to go richer 145)
Air correctors 185 (don't go richer, ie smaller a/c, but might want 190)
idle jets 55
pump jets 40

Certainly at sea level that will get you 9/10 there. As for altitude, dunno really, never had to tune a car at your kind of high altitude, guess it will want leaning out some.

Glad-u-like the forum, nice of you to say so, too few do.

GC

Thanks Guy,


Does 110/110 LC sound ok?

Suppose running it will tell a bunch


Robert Kenney

Sure, 110 is fine,

especially given the small carburettors, it will lead to a stronger bottom-end mid range torque characteristic than overlapping them at 100-102 or so.

GC