Race Engine Forum UK

Hi

I have a racing punto i have just bought to race in the Irish punto series it has a Tipo 1400 engine and box and everything is pretty much standard the camshaft is a Colombo Bariani FT.120.280S fitted with a vernier pulley but i cannot see any timing marks on the cam!....can anybody help me out with the valve timing with no markings as it is 23 years since i served my time and am a bit rusty.... :roll:

G

http://guy-croft.com/viewtopic.php?t=124

GC

Guy Croft wrote:http://guy-croft.com/viewtopic.php?t=124

GC

When you say Full lift spec for cam?.... my cam is a Colombo Bariani FT.103.280S so would this mean that the Full lift spec for my cam is 103deg?....

G

Hi,

I assume the C&B number in the first post was wrong.

Colombo Bariani FT.103.280S is an 8v SOHC profile with 10.3mm lift

Duration at true running clearance 0.4 in 0.5 ex : 280 crank deg in 268 deg ex

C&B recommended Inlet Full Lift: 112 crank deg ATDC on inlet stroke.

LATDC I think is 1.8mm

GC

Guy Croft wrote:Hi,

I assume the C&B number in the first post was wrong.

Colombo Bariani FT.103.280S is an 8v SOHC profile with 10.3mm lift

Duration at true running clearance 0.4 in 0.5 ex : 280 crank deg in 268 deg ex

C&B recommended Inlet Full Lift: 112 crank deg ATDC on inlet stroke.

LATDC I think is 1.8mm

GC

Guy

When you say true running clearance do you mean the clearance between the cam and the shim as in tappet clearance?. Also in your post All the power is in the head part 6 you talk about Ramp, do the clearances above take this into account?.

Gary

True running clearance is the manufacturer's stated running clearance measured between the base circle and the tappet (shim), in other words with the cam lobe point skywards.
I'm pretty sure C&B state duration based on true running clearance. In other words if you ran no clearance the duration would appear longer, not that one would do that, the cam would wear out. It's important that the cam ramp and then flank meet the tappet in an orderly fashion..

GC