milling e7tes and 1.7 roller rockers.....questions

[PKRWUD]

Okay, first of all you need to understand your compression. The advertised compression was 9.1:1, stock, but when calculated in the real world, including the space allowed by the head gasket and the area above the top piston rings, your real compression is closer to 8.8:1. The maximum amount of head surface that can be straight-cut milled without having an alignment problem with the intake is .040". This would decrease your combustion chamber size to roughly 57.8 cc, and would increase your real compression to approximately 9.5:1. Doing such, without any other mods, would add about 25 horsepower. I can't say for certain that 1.7 rockers would still allow the required piston to valve clearance, but I suspect you would be fine. Still, you should always check it with clay before the final assembly.

Take care,
-Chris