Valve Clearances CGA3

[Ihtisham Rauf]

Just checked the valve clearances on the 10.2:1 CGA3 engine. The engine is sitting in the garage and cold. It has 270 deg 9mm lift Autosprint regrind cams.

I was told that a single shim was placed under each bucket to bring the valve clearances up to spec to compensate for the reground cams.

These are the results I got using a feeler gauge:

Inlet 1 - 0.203mm went in nicely, 0.229mm didn't go in
Inlet 2 - 0.152mm went in nicely, 0.178mm didn't go in
Inlet 3 - 0.127mm went in nicely, 0.178mm didn't go in
Inlet 4 - 0.203mm went in nicely, 0.229mm didn't go in

Exhaust 1 - 0.305mm went in nicely, 0.330mm didn't go in
Exhaust 2 - 0.229mm went in nicely, 0.254mm was a tight squeeze but just about went in
Exhaust 3 - 0.356mm went in nicely, 0.381mm didn't go in
Exhaust 4 - 0.254mm went in nicely, 0.279mm didn't go in

Would someone please be able to tell me whether these are okay? I have read that 0.25mm is a good target on inlet and 0.30mm on exhaust, but not sure if this is for a CG10, or CG13 or CGA3, and whether cams and compression ratio make a difference, as mine is on aftermarket cams and 10.2:1 compression ratio.

Many thanks!

 

[frank]

the 2 are a bit tight eh, but should be fine ihtisham
they usually open up when warm, its just the first few seconds of startup where they close up
when the head is still cold but the exh gasses head up the valve stems

 

[Ihtisham Rauf]

the 2 are a bit tight eh, but should be fine ihtisham
they usually open up when warm, its just the first few seconds of startup where they close up
when the head is still cold but the exh gasses head up the valve stems

Okay thanks for the info Frank