International Lancia Forums

Can anyone tell me what is the recommended diameter for cam lobes for a series 1 Fulvia.1.3 rallye?

I have two sets, one with a diameter of 31mm and one with a diameter of 29 mm. The head has been skimmed as well.

Another point, there are 2 springs on trhe gearbox. One for the clutch return and one for centering the gear lever. In the parts book they are different numbers, is it important that they differ or is it a matter of feel?.... as I have a few return springs and none of the centering springs.

The cams in S1 cars are usually stamped with 818.100 (2C, GT,coupe1.2,coupe ralley 1.3) or 818342 (coupe1.3S,1.3HF) Lobe dia is half the story as the lift is the lobe diametre minus the base circle. If your base circle is 25 with lobe dis 31 the lift is 6mm. if the 29mm lobe has a basecircle of 23mm it has also a lift of 6mm. (times 1.5 due to the offcentre rocker gives about 9mm actual valve lift.)

No hat's interesting.. The set i have which are stamped 818.100 have a base diam of 23mm with 6 mm lift and the other set (not stamped) has a base 05 25mm with 6mm lift as you say.

Which do you recomend that I use and why? The car is a series 1 1.3s Rallye

Both types have the same lift but different timing. The 818.100 is milder and should not be in a 1300S engine. The unmarked cams should be compaired with a marked 818.342 set or checked with a degreewheel and dial gauge to check if it has the timing 28-66.