[500ef]

Does anyone knows what is the service limit for "shaving" or "skimming" ecotec 1.8's cylinder head?

In Brazil we can run with E100 (It's 94% ethanol + 6% watter, actually), and this fuel allows compression ratio up to 14:1.

I already did it in other cars (S10 2.4 and Astra 2.0). The service limit for them is 1,5mm and I "shaved" 2mm from both.

But, cruze's cylinder head is less known here. The 3 years warranty of firsts cars sold here (mine included) are about to finish (October 2011 to October 2014).

I just bought another cylinder head at junkyard and did some measures:

The "half moon" mark have 2mm deep (at S10 and Astra, this mark shows how much material you can "shave").

Stock compression ratio is 10,5:1

With 1mm cylinder head shaving, compression ratio must be 11,6:1

With 1,5mm cylinder head shaving, compression ratio must be 12,2:1

With 2,0mm cylinder head shaving, compression ratio must be 12,7:1

Thanks and sorry for my bad english.

 

[500ef]

There is no such information in your service /repair manual (official or not)?

Like I said, ecotec engines are less known here and GM Brazil dont give us too much information yet (warranty).