Some Qs About Fitting A Thicker Head Gasket Z20Le*

What do you guys think about fitting a thicker head gasket which has the effect of reducing compression ratio. e.g. Cometic 5-layer (1.78mm) gaskets.

• How does fitting a thicker head gasket affect the cam timings now that the belt would be stretched?
• Can I reuse the belt after I fit the gasket, or should I fit a new one?
• Can standard stock z20let ECU manage the now lower compression ratio?

best person to ask would be Chip on vauxsport

What do you guys think about fitting a thicker head gasket which has the effect of reducing compression ratio. e.g. Cometic 5-layer (1.78mm) gaskets.

• How does fitting a thicker head gasket affect the cam timings now that the belt would be stretched?
• Can I reuse the belt after I fit the gasket, or should I fit a new one?
• Can standard stock z20let ECU manage the now lower compression ratio?

1. Belt wont be affected as the adjuster will cope with the extra 0.5mm
2. I'd suggest fitting a new belt as they are cheap and saves you repeating the job. Also inspect and fit a new adjuster if it looks worn or dry (ie not flexing properly).
3. The car would benefit from a RR session and map tweak, but should run ok without I expect. You may find you are down on torque at low revs.

Why are you lowering the compression anyway, are u expecting boost to increase with some mods ?

Edited by Nev, 31 March 2012 - 12:36 PM.